Reference: the agents section of the cluster's settings

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -39,6 +39,14 @@ jobs:
       - name: Build
         run: go build ./...
 
+      # llmgw-kb runs on people's own machines, Windows included, which no
+      # test here runs on: building it for each catches a Unix-only call.
+      - name: Build llmgw-kb for every system
+        run: |
+          for target in windows/amd64 windows/arm64 darwin/amd64 darwin/arm64 linux/amd64 linux/arm64; do
+            CGO_ENABLED=0 GOOS="${target%/*}" GOARCH="${target#*/}" go build -o /dev/null ./cmd/llmgw-kb
+          done
+
       # The Terraform provider is a module of its own, which ./... above does
       # not reach. Its tests check its client against docs/admin-api.openapi.json,
       # so a change to the admin API that breaks the provider fails here. The

.gitea/workflows/release.yml

@@ -55,6 +55,21 @@ jobs:
             (cd dist && sha256sum "${name}" >> checksums.txt)
           done
 
+          # llmgw-kb, which people run on their own machines to put their
+          # documents into a knowledge base: Windows too, which llmgw itself
+          # does not build for.
+          for target in windows/amd64 windows/arm64 darwin/amd64 darwin/arm64 linux/amd64 linux/arm64; do
+            os="${target%/*}"; arch="${target#*/}"
+            ext=""; [ "$os" = windows ] && ext=".exe"
+            name="llmgw-kb-${version}-${os}-${arch}${ext}"
+            echo "building $name"
+            CGO_ENABLED=0 GOOS="$os" GOARCH="$arch" go build \
+              -trimpath \
+              -ldflags "-s -w -X gitea.mynodes.xyz/ilker/llmgw/internal/version.Version=${version}" \
+              -o "dist/${name}" ./cmd/llmgw-kb
+            (cd dist && sha256sum "${name}" >> checksums.txt)
+          done
+
           # The reverse proxy configurations, so a release page carries
           # everything install.md asks for and the repository is not needed.
           for f in deploy/proxy/Caddyfile deploy/proxy/nginx.conf; do
@@ -91,6 +106,7 @@ jobs:
           # test the cross-compiled ones, which is why the native build is
           # checked rather than assumed.
           ./dist/llmgw-${version}-linux-amd64 --version
+          ./dist/llmgw-kb-${version}-linux-amd64 --version
           cat dist/checksums.txt
 
       # Signed, so a machine that trusts the key built into it installs

BACKLOG.md

@@ -807,14 +807,34 @@ Patroni configuration. The firewall's allowed set is the cluster's membership
 removed changes every machine's rules. Retires `firewall.Admit` and
 `firewall_networks` in server.yaml (imported into the store).
 
-### E3. agent.yaml down to bootstrap (M)
+### E3. agent.yaml down to bootstrap (M) — done 2026-10-08 (branch `settings-e`)
 agent.yaml keeps the control planes' addresses, its certificate and its id.
 Labels, fabrics, engines, heartbeat and supervisor settings move to the
 store per node and reach the agent over its stream; a change to the file is
 noticed and the agent restarts itself.
+Built as a section of the cluster's settings rather than a store of its own,
+so history, audit, `ctl config`, the console and the portal page cover it:
+`agents.default` and `agents.nodes.<id>` (config.AgentSettings; bootstrap
+keys node_id/server(s)/hostname/mgmt_addr/tls refused; each node's merge
+loaded as an agent would, so a bad fabric is refused on save). A live key:
+the control plane sends ControlMessage.AgentSettings on register and, a
+second apart per node, on change; the agent compares with what it started on,
+checks it loads beside its agent.yaml (else logs and keeps running), keeps it
+in /var/lib/llmgw-agent/agent-settings.yaml and restarts (engines adopted).
+At start: agent.yaml < kept settings < LLMGW_ env; kept settings that no
+longer load are set aside, never a reason not to start. agent.yaml is
+watched every 10 s and restarted on when it changes and loads. Left: file
+keys are not imported into the settings (they keep working under them);
+`node add` still writes a full agent.yaml; labels have two homes now
+(`ctl label`, which wins, and agents.*.labels).
 
-### E4. Web settings page (S)
+### E4. Web settings page (S) — done 2026-10-08 (branch `settings-e`)
 The same document, edited on /admin/settings, for whoever has no terminal.
+Built: administrators only (staff roles get 404: webhook secrets), checked by
+the same function as PUT /api/v1/settings, made from a base version or
+refused on a newer one (the edit kept in the editor), history with view and
+roll back as a new version, audit with the size not the body, English and
+Turkish, a Settings link in the menu.
 
 ---
 
@@ -829,47 +849,134 @@ ACL yet); a personal key or session names a project or team and gets that
 chain only, never the union of its person's memberships; PostgreSQL store
 only, off on SQLite with a sentence saying why.
 
-### F1. Store: collections, grants, chunks (M)
-- `pgvector` ≥ 0.8 installed on every Patroni member by `server init`
-  (`internal/cli/serverinit_postgres.go`), `CREATE EXTENSION` in the
-  migration; the SQLite migration has no tables, and the store reports the
-  feature unavailable.
-- Tables: `kb_collections` (id, org_id, owner `team:…`/`project:…`/`user:…`,
-  name, embed_model, dims, created_at), `kb_grants` (scope, scope_id,
-  collection, perm read|write — like `guard_attachments`), `kb_documents`
-  (name, digest, bytes, state, chunk count), `kb_chunks` (org_id,
-  collection, doc_id, ord, body, tsv, embedding) `PARTITION BY LIST
-  (org_id)`, a partition per organization, HNSW and GIN indexes per
-  partition.
-- Row-level security on `kb_chunks` against `current_setting('llmgw.org')`
-  and `llmgw.collections`, retrieval through its own role.
-- Rules, refused before anything is written: a grant never crosses
-  organizations; owner and grants resolve to existing scopes; deleting a
-  project/team/org and `users forget` delete their collections (`forget.go`).
-- Done: store tests on PostgreSQL, including an RLS test that a query
-  without the settings returns no rows.
+### F1. Store: collections, grants, chunks (M) — done 2026-10-08 (branch `rag`)
+Built (`internal/store/knowledge.go`, migration 0035 PostgreSQL only):
+- `kb_collections` (owner scope/id, org, embed_model, dims), `kb_grants`
+  (read|write, any scope, never across organizations; a key needs a
+  project; a person needs a membership in the organization),
+  `kb_documents` (digest: the same again is no change, a new one replaces
+  in one transaction).
+- `kb_chunks` is created when the store opens, not in a migration (a
+  migration needing an extension would stop the control plane; one that
+  skipped it would never run again): partitioned by organization (hashed
+  partition name), `tsv` generated (`simple`), GIN on the parent, one
+  partial HNSW index per collection on its organization's partition
+  (`embedding::vector(dims)`, `WHERE collection = '<id>'`). EXPLAIN on
+  20k rows: partition pruned, that index used, policy applied.
+- RLS FORCEd on `kb_chunks` against `llmgw.kb_org`/`llmgw.kb_collections`
+  (set with set_config per transaction), one role — the table owner — not
+  a separate one. Chunks are deleted by the foreign-key cascade from their
+  document, which RLS does not block.
+- `CollectionsFor(Effective, write)`: owner or grant anywhere on the chain;
+  no organization (personal key without a project) reads nothing.
+- `SearchChunks`: per collection nearest-neighbour (literal id and cast so
+  the partial index is used) plus a full-text arm with any word
+  (`a | b`, lowercased by the database, not Go), fused by reciprocal rank.
+- Deleting a project/team/org that owns collections is refused like one
+  with members (changed from "deleted with them": every other delete in the
+  tree refuses); DeleteUser/ForgetUser delete the person's collections;
+  deleting an organization drops its partition; grants to a deleted scope go.
+- `server init` installs `postgresql-N-pgvector` / `pgvector_N` and enables
+  it; pgha installs it on every member at setup and enables it on the
+  leader on every run. Neither stops on failure.
+Left: a cluster set up before (the PoC) gets no package from a rerun of
+pgha on a running cluster — install by hand or add an upgrade step;
+`server restore`/`CopyTo` do not carry kb tables (SQLite → PostgreSQL only,
+and SQLite has none); tests need `LLMGW_TEST_POSTGRES` pointing at a
+pgvector database as a non-superuser (a superuser bypasses RLS).
 
-### F2. Ingest (M)
-- `llmgw ctl kb create|list|delete|grant|revoke|docs`, `ctl kb add
-  <collection> <files…>`, admin API under `/api/v1/kb`, audit events.
-- Text from PDF (text layer), DOCX, HTML, Markdown, plain text — in Go, no
-  Python. Split on headings/paragraphs, ~500 tokens with overlap. Embedded
-  through the router at the bronze band, accounted to the collection's
-  owner. One transaction per document; same digest skipped, changed digest
-  replaces. OCR out of scope.
-- Console: a Knowledge screen (collections, documents, grants; add, grant,
-  revoke, delete); `docs/console.md`, `docs/knowledge.md`.
+### F2. Ingest on the user's machine (L) — done 2026-10-08 (branch `rag`)
+Uploading whole files to the control plane was dropped: a PDF is 20–100×
+its text, and the work belongs where the files are. Instead a small client,
+`llmgw-kb`, run by the person on their own machine with their own key:
+- **Its own binary** (`cmd/llmgw-kb`), for Windows, macOS and Linux on amd64
+  and arm64. `llmgw` itself does not build on Windows (agent syscalls), and
+  employees' laptops should not carry the server, agent and setup screens. A
+  test keeps server packages out of its imports.
+- `llmgw-kb sync <collection> <dir|file…> [--include/--exclude globs]
+  [--dry-run] [--delete]`: scan → local catalog (path, size, mtime, sha256;
+  cache under os.UserCacheDir, digests not recomputed for unchanged files)
+  → the collection's manifest from the gateway (name → digest only) → diff
+  → for new/changed files only: extract, chunk, embed through the gateway's
+  `/v1/embeddings` with the person's key (its accounting, limits, guard and
+  band apply), and send name, digest, chunk texts and vectors; `--delete`
+  removes documents whose files are gone. `--dry-run` lists what would leave
+  the machine and how much. A file that cannot be read (locked, unsupported,
+  no text) is skipped with the reason; the run goes on.
+- **Formats, as many as possible.** Built in, pure Go: PDF (text layer),
+  DOCX/XLSX/PPTX, ODT/ODS/ODP, RTF, EPUB, HTML/XHTML, EML (text and HTML
+  parts), Jupyter notebooks, subtitles (SRT/VTT), CSV/TSV, JSON/YAML/XML,
+  Markdown/RST/AsciiDoc/Org, plain text and source code; ZIP archives
+  recursed into. With a helper found on the machine: legacy DOC/XLS/PPT, RTF
+  and anything else LibreOffice opens (`soffice --headless --convert-to`),
+  images and scanned PDFs through Tesseract (`tur+eng`). Text in UTF-8,
+  UTF-16 (BOM) or Windows-1254/1252 is converted to UTF-8.
+- **Across systems:** document names relative to the synced root, `/`
+  separated, Unicode NFC (macOS hands out NFD), a warning for two names that
+  differ only in case; CRLF → LF; key from `LLMGW_API_KEY` or `llmgw-kb
+  login` (os.UserConfigDir, 0600 where that means something); the system's
+  CA store, `--ca` for another.
+- **Gateway endpoints** (client listener, person's key):
+  `GET /v1/kb/collections` (what this key may read/write),
+  `GET /v1/kb/collections/{id}/manifest`, `PUT
+  /v1/kb/collections/{id}/documents` (one document per request: name,
+  digest, bytes, chunks with text and embedding; dims checked, chunk count
+  and size bounded), `DELETE …/documents?name=`. Write needs a write grant
+  or ownership on the key's chain (`CollectionsFor(…, write)`); otherwise
+  404.
+- **Administration** stays with operators: `llmgw ctl kb
+  create|list|delete|grant|revoke|docs`, admin API `/api/v1/kb`, audit,
+  console screen; `docs/knowledge.md`.
+- Trade-off accepted: vectors come from the client, so a writer could store
+  vectors that do not match their text — only in collections they may
+  already write.
+Built: `internal/kb/extract` (formats above; helpers found on PATH and in
+each system's install places), `internal/kb/chunk` (≈1800 characters under
+the heading path, a paragraph of overlap, sections kept apart once a chunk
+is a third full), `internal/kb/kbsync` (ledger in SQLite at
+os.UserConfigDir/llmgw-kb/ledger.db: documents keyed by gateway, collection
+and name with file, size, mtime, digest, state, reason; runs), `cmd/llmgw-kb`
+(login, collections, sync, status, history, formats), `internal/router/kb.go`
+(the four gateway endpoints, `X-Llmgw-Project` for personal keys, audit),
+`internal/control/adminapi/kb.go` + `llmgw ctl kb` + console Knowledge
+screen, `docs/knowledge.md`; CI builds the client for all six targets and
+releases attach it. Tested: every format from generated fixtures and a
+Turkish PDF (OCR path with Tesseract here), sync against a fake gateway and
+end to end against the router on pgvector.
+Tried on the PoC 2026-10-08 (control planes 140 and 150 on a dev build of
+this branch; their previous binary is /usr/local/bin/llmgw.pre-rag): Ubuntu's
+pgvector 0.6.0 installed on 149/150 and enabled; bge-m3's weights were never
+in the mirror (fetched from CompendiumLabs/bge-m3-gguf@1864f47f) and it is
+held at 1 replica; tree Demo/ik/belgeler and Demo/satis/crm with a key each;
+collection Demo/politikalar filled from a Mac through an SSH tunnel with ten
+Turkish files in nine formats (9 sent in 5 s, the .doc skipped for want of
+LibreOffice; a rerun sent nothing in 0 s; a changed file alone was sent).
+Nine Turkish questions each found their page first once search scored by
+similarity plus word coverage (rank fusion had got two wrong). The other
+team's key saw no collection and got 404 by id; with a read grant it read
+and could not write; revoked, nothing again. On the live store the llmgw
+role (not superuser, no BYPASSRLS) sees 0 chunks with no scope set and 0
+with the organization alone.
+Left: the gateway's collection list shows the owner as team:ID, not its
+path; no LibreOffice on the dev machine, so the legacy
+Office path is untested beyond its error; the client is unsigned (Gatekeeper
+and SmartScreen warn); Outlook `.msg` is not read; one document over ~60 MiB
+of JSON (a few thousand pages) is refused rather than split.
+PostgreSQL tests of store, router and adminapi share LLMGW_TEST_POSTGRES and
+the store's TRUNCATE each test; run them with `go test -p 1` or one package
+at a time, or a router test loses its rows mid-run.
 
-### F3. Retrieval on the request path (M)
+### F3. Retrieval on the request path (M) — done 2026-10-08 (branch `rag`)
 - `llmgw.knowledge: [collections]` in the body (stripped before the
   engine), or default collections per project/key.
 - Allowed set from the caller's chain (§7.9.2), cached like limits; grants
   add up down the tree. Personal keys and sessions need `x-llmgw-project`
   (or the playground's picker) naming a scope the person is a member of.
 - A collection not allowed answers 404, exactly as a missing one.
-- Hybrid search with the filter inside the query (`hnsw.iterative_scan`,
-  `WHERE org_id = $1 AND collection = ANY($2)`), full-text arm merged by
-  reciprocal rank, `/v1/rerank` when a reranker is in the catalog. Top
+- Hybrid search with the filter inside the query (per collection, its own
+  partial index; pgvector 0.6 is enough —
+  scored by similarity plus the share of the question's words held (built
+  in F1/F2 as SearchChunks), `/v1/rerank` when a reranker is in the catalog. Top
   chunks into a system message with document and position;
   `x-llmgw-sources` lists them.
 - Leaks closed: answer-cache key includes the allowed set; per-organization
@@ -879,6 +986,25 @@ only, off on SQLite with a sentence saying why.
   (including via cache), that a personal key without a project is refused,
   metrics (retrieval latency, chunks returned), docs.
 
+Built (`internal/router/rag.go`): `X-Llmgw-Knowledge` (header, as the
+other llmgw extensions are, not a body field), `X-Llmgw-Knowledge-K`;
+collections from the key's chain (kbEffective, shared with the kb
+endpoints), 404 for one not readable; the question embedded through the
+ordinary path on the caller's principal; SearchChunks; passages trimmed to
+the model's context; added to the one leading system message (or a new
+one); `x-llmgw-sources`; before guardInput; never cached; metrics. Default collections built (kb_defaults on org/team/project/key, narrowest
+wins, 30 s cache, `ctl kb default`, console action; never refuse); the
+portal chat's Documents picker (collection, default or none; sources listed
+under the answer; a header the page sends itself is dropped). `cache_salt` per organization on requests given passages, sent to vLLM
+replicas only (chosen replica's engine). Checked on the PoC 2026-10-08:
+vLLM 0.30.0 (cuda01) with TinyLlama-1.1B AWQ run by hand beside the 35B in
+the card's last 2.3 GB — a 668-token prompt reused 656 tokens under the same
+salt and 0 under another's, with identical text (llmgw cannot place it
+there: placement takes whole GPUs). Live on the PoC: a team default answers
+a request without the header, `none` turns it off, an explicit header with
+k=2 gives two sources and no more, llmgw-kb lists owners by path. Left: returned passages
+are not audited per request (the header and the kept request record them).
+
 ### F4. Adapter training (L, after F1–F3)
 A run-to-completion job placed by the control plane like a replica and
 supervised by the agent like an engine, in a Python environment the agent

CHANGELOG.md

@@ -18,11 +18,86 @@ is only released once its **exit criterion** is met, not when its code lands.
 | v0.11.0 | — | High availability from setup, the setup and console screens, usage sums and per-tenant alerts | released |
 | v0.12.0 | — | The cluster's settings in the store, in force when changed; the firewall switch; wipe | released |
 | v0.13.0 | — | The whole system stopped and started from one command; Qwen3Guard judges, on a GPU and CPUs together | released |
+| v0.14.0 | — | Knowledge bases: documents from people's own machines, kept apart per tenant, answered from | released |
 | v1.0.0 | 5 | Tenancy, prefix affinity, benchmarking | planned |
 
 Until v1.0.0 the minor version is the breaking one: configuration formats and Go
 APIs change between minors without a deprecation period.
 
+## Unreleased
+
+### Added
+
+- **The cluster's settings on the portal** (BACKLOG E4): `/admin/settings`
+  for administrators. It edits the document `llmgw ctl config edit` opens:
+  checked as a control plane would load it, refused when made from a
+  version since replaced, with the history to view and roll back. Changes
+  are audited by size, never by contents.
+- **The nodes' agent settings in the cluster's settings** (BACKLOG E3):
+  `agents.default` and `agents.nodes.<id>` hold everything agent.yaml can
+  say but the agent's id, control planes, address and certificate. They are
+  sent to the agents as they change; an agent starts again on new settings,
+  or on an edited agent.yaml, with its engines serving throughout. Settings
+  that would not load are refused on save, and set aside on a node rather
+  than keep its agent from starting. Nodes need this release to follow
+  them.
+
+## v0.14.0 — 2026-10-08
+
+Knowledge bases: a company's documents, put in by people from their own
+machines, kept apart per tenant, and answered from.
+
+**Upgrading.**
+- **pgvector on a cluster set up before this release.** Knowledge bases
+  need pgvector, which `server init` and the high-availability database
+  setup now install, but a rerun on a running cluster does not:
+  1. Install `postgresql-<version>-pgvector` on every database machine.
+  2. As postgres, run `CREATE EXTENSION vector` in llmgw's database.
+  3. Restart the control planes.
+  Until then everything else works, and `llmgw ctl kb list` says why
+  knowledge bases are off. On a SQLite store they stay off.
+- **An embedding model.** A collection needs a catalog model with
+  `capabilities.embeddings`, for example bge-m3, whose weights are in the
+  mirror.
+- **The client.** People download `llmgw-kb` for their system from this
+  release.
+
+### Added
+
+- **Collections and who may read them.** A collection is owned by an
+  organization, team, project or person. Grants add up down the tenancy
+  tree and never cross an organization. A collection a key may not read is
+  answered as one that does not exist. Chunks are kept in PostgreSQL with
+  pgvector, partitioned by organization, with an HNSW index per collection,
+  and row-level security on the table as a second line behind every
+  query's own filter. A project, team or organization that owns collections
+  is not deleted; a person's collections go with their account.
+- **`llmgw-kb`**, its own download for Windows, macOS and Linux, run by
+  people with their own key. It reads documents where they are and sends
+  text and vectors, never the files, for what changed only; a SQLite ledger
+  on the machine remembers what it did.
+  - It reads PDF, Word, Excel, PowerPoint, OpenDocument, RTF, EPUB, HTML,
+    MHTML, mail with attachments, notebooks, subtitles, ZIP archives, and
+    text and source code in any common encoding.
+  - Legacy Office files are read with LibreOffice, and scanned pages with
+    Tesseract, when those are installed.
+  - `--dry-run` says what would leave the machine; `--delete` removes only
+    what that machine sent.
+- **Answers from documents.** A chat request names collections in
+  `X-Llmgw-Knowledge`, or its part of the tree has a default (`llmgw ctl kb
+  default`). The best passages, chosen by meaning plus a little for the
+  question's words, are added to the system message, numbered, and
+  `x-llmgw-sources` says which were used. This happens before the
+  guardrails judge the request, and the answer is never served from the
+  answer cache. On vLLM replicas the organization's `cache_salt` keeps
+  tenants' prefix caches apart. It works through the Responses and Messages
+  APIs too.
+- **Administration**: `llmgw ctl kb` (create, list, grant, revoke, default,
+  docs, rm, search, delete), `/api/v1/kb`, the console's Knowledge screen,
+  and a Documents picker on the portal's chat page.
+- Metrics `llmgw_kb_retrievals_total` and `llmgw_kb_retrieval_seconds`;
+  [docs/knowledge.md](docs/knowledge.md).
+
 ## v0.13.0 — 2026-10-08
 
 The whole system stopped, started and restarted from one command, a

Makefile

@@ -6,6 +6,7 @@ LDFLAGS := -X '$(MODULE)/internal/version.Version=$(VERSION)'
 
 build:
 	go build -ldflags "$(LDFLAGS)" -o bin/llmgw ./cmd/llmgw
+	go build -ldflags "$(LDFLAGS)" -o bin/llmgw-kb ./cmd/llmgw-kb
 
 test:
 	go test ./...

README.md

@@ -3,8 +3,9 @@
 A single-binary LLM gateway for clusters with multiple InfiniBand fabrics,
 NVLink domains and heterogeneous GPUs.
 
-It serves LLMs running on your own GPU servers (vLLM / SGLang) behind one
-OpenAI-compatible endpoint. Design document: [llmgw-plan.md](llmgw-plan.md).
+It serves LLMs running on your own GPU and CPU servers (vLLM, SGLang,
+llama.cpp, TensorRT-LLM) behind one OpenAI- and Anthropic-compatible
+endpoint, and answers from your own documents. Design document: [llmgw-plan.md](llmgw-plan.md).
 
 ## Getting started
 
@@ -37,6 +38,9 @@ Releases track the roadmap phases; see [CHANGELOG.md](CHANGELOG.md).
 | v0.9.0 | — | Managing people and the tenancy tree | released |
 | v0.10.0 | — | InfiniBand fabrics and NVLink, doctor, node add, engines installed by the nodes | released |
 | v0.11.0 | — | High availability from setup, the setup and console screens, usage sums and per-tenant alerts | released |
+| v0.12.0 | — | The cluster's settings in the store, in force when changed; the firewall switch; wipe | released |
+| v0.13.0 | — | The whole system stopped and started from one command; Qwen3Guard judges, on a GPU and CPUs together | released |
+| v0.14.0 | — | Knowledge bases: documents from people's own machines, kept apart per tenant, answered from | released |
 | v1.0.0 | 5 | Tenancy, prefix affinity, benchmarking | planned |
 
 As of v0.6.0 a cluster runs unattended: agents report their hardware, the
@@ -44,38 +48,60 @@ control plane places replicas — including ones larger than a single machine
 models load when someone asks for them and stop when nobody does, and keys,
 budgets and rate limits decide who may use any of it.
 
-Since v0.11.0, not yet released (see [CHANGELOG.md](CHANGELOG.md),
-"Unreleased"):
+Since v0.11.0 (each release's detail is in [CHANGELOG.md](CHANGELOG.md)):
 
-- **Security hardening** — signed releases only, a token on the admin API,
-  engines not run as root, TLS for the agent port, etcd and Patroni, a
-  firewall for llmgw's internal ports, encrypted backups, bounded
-  connections, sign-in throttling, a Content-Security-Policy.
-- **Guardrails** — policies that check requests and answers (PII, secrets,
-  prompt injection, deny patterns, a judge model such as Llama Guard), in
-  observe or enforce mode, attached to any part of the tenancy tree:
+- **Knowledge bases** (v0.14.0). People put a company's documents in from
+  their own machines with `llmgw-kb`, a separate download for Windows,
+  macOS and Linux that reads PDF, Office, OpenDocument, mail and many more
+  formats and sends text and vectors, never the files. Collections are kept
+  apart per tenant, down to row-level security in PostgreSQL. A chat
+  request, or a part of the tree by default, is answered from them with
+  its sources: [docs/knowledge.md](docs/knowledge.md).
+- **One command for the whole system** (v0.13.0): `llmgw stop`, `start` and
+  `restart`. Qwen3Guard is the guardrails' judge, on a GPU and on CPUs
+  together.
+- **Settings that apply when changed** (v0.12.0). The cluster's
+  configuration lives in the store, the same on every control plane and in
+  force within seconds (`llmgw ctl config`, the console's Settings). The
+  firewall can be switched on and off for the whole cluster.
+- **Security hardening** (v0.11.2): signed releases only, a token on the
+  admin API, engines not run as root, TLS for the agent port, etcd and
+  Patroni, a firewall for llmgw's internal ports, encrypted backups,
+  bounded connections, sign-in throttling, a Content-Security-Policy.
+- **Guardrails** (v0.11.2). Policies check requests and answers for PII,
+  secrets, prompt injection, deny patterns, and with a judge model; they
+  observe or enforce, and attach to any part of the tenancy tree:
   [docs/guardrails.md](docs/guardrails.md).
-- **Administration** — an audit log of every change (`ctl audit`), staff
-  roles (viewer, operator, billing, admin), single sign-on through OpenID
-  Connect and provisioning through SCIM 2.0, key lifetime limits and
-  rotation with overlap (`keys ttl`, `keys rotate`), usage export as CSV
-  (`ctl usage export`).
-- **Notifications** — webhooks, signed or Slack-shaped, for a model parked,
-  a node lost, a budget spent and new weights published (`notify.webhooks`,
-  `ctl notify test`), and Alertmanager receiver templates.
-- **Traffic and models** — request tags, canaries of new weights with
-  automatic rollback, quality suites gating updates, a response cache,
-  kept and replayed requests, batches, Anthropic's Messages API, more of
-  OpenAI's (structured output, images, rerank, audio, moderations),
-  scaling by the clock, SLO-aware admission, TensorRT-LLM, MIG, models
-  imported from Ollama, routing by what each vLLM replica's cache holds,
-  LoRA adapters loaded on demand, other llmgw clusters as providers, and
-  placement that knows racks, PDUs and power caps.
-- **Operations** — `server restore` and off-machine backup copies, secrets
-  in Vault, forgetting a person and keeping a project's requests in the
-  cluster, offline installs from a bundle, a Helm chart, tracing from the
-  control plane to the engines, the admin API in OpenAPI with a Terraform
-  provider, and the portal in English and Turkish with its docs at /docs.
+- **Administration** (v0.11.2):
+  - an audit log of every change (`ctl audit`);
+  - staff roles (viewer, operator, billing, admin);
+  - single sign-on through OpenID Connect and provisioning through SCIM
+    2.0;
+  - key lifetime limits, and rotation with overlap (`keys ttl`, `keys
+    rotate`);
+  - usage export as CSV (`ctl usage export`).
+- **Notifications** (v0.11.2): webhooks, signed or Slack-shaped, for a
+  model parked, a node lost, a budget spent and new weights published, and
+  Alertmanager receiver templates.
+- **Traffic and models** (v0.11.2):
+  - request tags, canaries of new weights with automatic rollback, and
+    quality suites gating updates;
+  - a response cache, kept and replayed requests, and batches;
+  - Anthropic's Messages API, and more of OpenAI's (structured output,
+    images, rerank, audio, moderations);
+  - scaling by the clock, and SLO-aware admission;
+  - TensorRT-LLM, MIG, and models imported from Ollama;
+  - routing by what each vLLM replica's cache holds, and LoRA adapters
+    loaded on demand;
+  - other llmgw clusters as providers, and placement that knows racks,
+    PDUs and power caps.
+- **Operations** (v0.11.2):
+  - `server restore`, off-machine backup copies, and secrets in Vault;
+  - forgetting a person, and keeping a project's requests in the cluster;
+  - offline installs from a bundle, and a Helm chart;
+  - tracing from the control plane to the engines;
+  - the admin API in OpenAPI, with a Terraform provider;
+  - the portal in English and Turkish, with its docs at /docs.
 
 Every one of these is in the console as well as on the command line:
 [docs/console.md](docs/console.md).
@@ -124,6 +150,9 @@ Every page is also in the binary: `llmgw docs`, or **Manual** in the console.
   official OpenAI and Anthropic SDKs, and llmgw's extensions
 - [docs/guardrails.md](docs/guardrails.md) — checking requests and answers:
   policies, detectors, a judge model, and where each applies
+- [docs/knowledge.md](docs/knowledge.md) — knowledge bases: collections,
+  who may read them, `llmgw-kb` on people's machines, and answers from
+  documents
 - [docs/choosing-models.md](docs/choosing-models.md) — which models to run,
   how many of each, and where the weights should live
 
@@ -152,7 +181,7 @@ Every page is also in the binary: `llmgw docs`, or **Manual** in the console.
 ## Building
 
 ```sh
-make build      # bin/llmgw
+make build      # bin/llmgw and bin/llmgw-kb
 make test       # unit tests
 make race       # with the race detector
 ```
@@ -169,6 +198,7 @@ llmgw ctl cordon gpu-a-01            # stop new placement, leave what runs
 sudo llmgw doctor                    # on a node: what its GPUs, NVLink and fabric need
 llmgw ctl audit --since 24h          # who changed what
 llmgw ctl usage export --from 2026-09-01 --to 2026-10-01 --by project,model
+llmgw ctl kb list                    # knowledge-base collections, grants, defaults
 ```
 
 Bare `llmgw` opens the console, which does all of this from one screen.

api/proto/llmgw/v1/agent.proto

@@ -73,6 +73,7 @@ message ControlMessage {
     ControlPlanes control_planes = 11;
     Firewall firewall = 13;
     RestartAgent restart_agent = 14;
+    AgentSettings agent_settings = 15;
   }
   // trace is the W3C trace context (traceparent, and tracestate when there
   // is one) of the control plane's span that sent this command, so what the
@@ -103,6 +104,17 @@ message Firewall {
   int32 engine_ports_to = 4;
 }
 
+// AgentSettings is what the cluster's settings say of this node's agent
+// (agents.default, with agents.nodes.<id> over it), sent when it registers
+// and whenever they change. The agent keeps it beside agent.yaml, which
+// holds only what it needs to start; over that file, it is what the agent
+// runs on. A change from what it runs on has the agent start again on it,
+// its engines serving throughout.
+message AgentSettings {
+  // yaml is agent.yaml's keys, as YAML; empty for none.
+  string yaml = 1;
+}
+
 // ControlPlanes is every control plane an agent may dial, sent by the leader
 // when an agent registers and whenever the list changes. The agent keeps it
 // beside its configuration, so a second control plane added after the node

cmd/llmgw-kb/main.go

@@ -0,0 +1,467 @@
+// Command llmgw-kb puts a person's documents into an llmgw knowledge base
+// from their own machine (BACKLOG F2): it reads the files there, cuts them
+// into chunks, has the gateway embed them with the person's key, and sends
+// the text and vectors — only for what changed since the last run, which a
+// ledger on the machine remembers.
+//
+// Its own binary, for Windows, macOS and Linux: it carries none of the
+// server, agent or setup code that llmgw does.
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"github.com/spf13/cobra"
+	"golang.org/x/term"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/extract"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/kbsync"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/version"
+)
+
+func main() {
+	if err := root().Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, "error:", err)
+		os.Exit(1)
+	}
+}
+
+// config is what `login` keeps: the gateway, the key, and for a personal key
+// the project it acts in.
+type config struct {
+	Gateway string `json:"gateway"`
+	Key     string `json:"key"`
+	Project string `json:"project,omitempty"`
+	CA      string `json:"ca,omitempty"`
+}
+
+func configPath() (string, error) {
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "llmgw-kb", "config.json"), nil
+}
+
+// loadConfig reads the saved configuration, with the environment over it:
+// LLMGW_URL, LLMGW_API_KEY, LLMGW_PROJECT.
+func loadConfig() (config, error) {
+	var c config
+	if p, err := configPath(); err == nil {
+		if b, err := os.ReadFile(p); err == nil {
+			if err := json.Unmarshal(b, &c); err != nil {
+				return c, fmt.Errorf("%s: %w", p, err)
+			}
+		}
+	}
+	for env, dst := range map[string]*string{"LLMGW_URL": &c.Gateway, "LLMGW_API_KEY": &c.Key, "LLMGW_PROJECT": &c.Project} {
+		if v := strings.TrimSpace(os.Getenv(env)); v != "" {
+			*dst = v
+		}
+	}
+	return c, nil
+}
+
+func client(flags *globalFlags) (*kbsync.Client, error) {
+	c, err := loadConfig()
+	if err != nil {
+		return nil, err
+	}
+	if flags.gateway != "" {
+		c.Gateway = flags.gateway
+	}
+	if flags.project != "" {
+		c.Project = flags.project
+	}
+	if flags.ca != "" {
+		c.CA = flags.ca
+	}
+	if c.Gateway == "" || c.Key == "" {
+		return nil, errors.New("no gateway or key: run `llmgw-kb login`, or set LLMGW_URL and LLMGW_API_KEY")
+	}
+	h, err := kbsync.NewHTTP(c.CA)
+	if err != nil {
+		return nil, err
+	}
+	return &kbsync.Client{Base: c.Gateway, Key: c.Key, Project: c.Project, HTTP: h}, nil
+}
+
+type globalFlags struct {
+	gateway, project, ca, ledger string
+}
+
+func (g *globalFlags) openLedger(ctx context.Context) (*kbsync.Ledger, error) {
+	p := g.ledger
+	if p == "" {
+		var err error
+		if p, err = kbsync.DefaultLedgerPath(); err != nil {
+			return nil, err
+		}
+	}
+	return kbsync.OpenLedger(ctx, p)
+}
+
+func root() *cobra.Command {
+	g := &globalFlags{}
+	cmd := &cobra.Command{
+		Use:   "llmgw-kb",
+		Short: "Put your documents into an llmgw knowledge base, from this machine",
+		Long: `llmgw-kb reads documents on this machine, cuts them into chunks, has the
+gateway embed them with your key, and sends the text and vectors to a
+knowledge base. Files are never uploaded. Run it as often as you like: a
+ledger on this machine remembers what was sent, and only what changed is
+read and sent again.`,
+		Version:       version.Version,
+		SilenceUsage:  true,
+		SilenceErrors: true,
+	}
+	cmd.PersistentFlags().StringVar(&g.gateway, "gateway", "", "the gateway's address (default: from login, or LLMGW_URL)")
+	cmd.PersistentFlags().StringVar(&g.project, "project", "", "the project a personal key acts in (default: from login, or LLMGW_PROJECT)")
+	cmd.PersistentFlags().StringVar(&g.ca, "ca", "", "a PEM file of certificates to trust besides the system's")
+	cmd.PersistentFlags().StringVar(&g.ledger, "ledger", "", "the ledger file (default: in your configuration directory)")
+	cmd.AddCommand(loginCmd(g), collectionsCmd(g), syncCmd(g), statusCmd(g), historyCmd(g), formatsCmd())
+	return cmd
+}
+
+func loginCmd(g *globalFlags) *cobra.Command {
+	return &cobra.Command{
+		Use:   "login",
+		Short: "Save the gateway's address and your key",
+		Long: `Asks for the gateway's address and your API key, checks them, and saves them
+in your configuration directory, readable by you only. The key is typed
+without being shown, so it does not end up in your shell's history.`,
+		Args: cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			c, _ := loadConfig()
+			in := bufio.NewReader(os.Stdin)
+			ask := func(q, def string) string {
+				if def != "" {
+					fmt.Fprintf(cmd.OutOrStdout(), "%s [%s]: ", q, def)
+				} else {
+					fmt.Fprintf(cmd.OutOrStdout(), "%s: ", q)
+				}
+				s, _ := in.ReadString('\n')
+				if s = strings.TrimSpace(s); s == "" {
+					return def
+				}
+				return s
+			}
+			c.Gateway = strings.TrimRight(ask("Gateway address (https://…)", or(g.gateway, c.Gateway)), "/")
+			fmt.Fprint(cmd.OutOrStdout(), "API key: ")
+			var key string
+			if term.IsTerminal(int(os.Stdin.Fd())) {
+				b, err := term.ReadPassword(int(os.Stdin.Fd()))
+				fmt.Fprintln(cmd.OutOrStdout())
+				if err != nil {
+					return err
+				}
+				key = strings.TrimSpace(string(b))
+			} else {
+				key, _ = in.ReadString('\n')
+				key = strings.TrimSpace(key)
+			}
+			if key != "" {
+				c.Key = key
+			}
+			c.Project = ask("Project, for a personal key (empty for a project's key)", or(g.project, c.Project))
+			if g.ca != "" {
+				c.CA = g.ca
+			}
+			h, err := kbsync.NewHTTP(c.CA)
+			if err != nil {
+				return err
+			}
+			cl := &kbsync.Client{Base: c.Gateway, Key: c.Key, Project: c.Project, HTTP: h, Wait: time.Second}
+			ctx, cancel := context.WithTimeout(cmd.Context(), 30*time.Second)
+			defer cancel()
+			cs, err := cl.Collections(ctx)
+			if err != nil {
+				return fmt.Errorf("the gateway refused: %w", err)
+			}
+			p, err := configPath()
+			if err != nil {
+				return err
+			}
+			if err := os.MkdirAll(filepath.Dir(p), 0o700); err != nil {
+				return err
+			}
+			b, _ := json.MarshalIndent(c, "", "  ")
+			if err := os.WriteFile(p, b, 0o600); err != nil {
+				return err
+			}
+			fmt.Fprintf(cmd.OutOrStdout(), "Saved in %s. This key reaches %d collection(s); `llmgw-kb collections` lists them.\n", p, len(cs))
+			return nil
+		},
+	}
+}
+
+func or(a, b string) string {
+	if a != "" {
+		return a
+	}
+	return b
+}
+
+func collectionsCmd(g *globalFlags) *cobra.Command {
+	return &cobra.Command{
+		Use:   "collections",
+		Short: "List the collections your key may read, and which it may add to",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			c, err := client(g)
+			if err != nil {
+				return err
+			}
+			cs, err := c.Collections(cmd.Context())
+			if err != nil {
+				return err
+			}
+			if len(cs) == 0 {
+				fmt.Fprintln(cmd.OutOrStdout(), "No collections. An administrator creates them and grants access (llmgw ctl kb).")
+				return nil
+			}
+			tw := tabwriter.NewWriter(cmd.OutOrStdout(), 2, 4, 2, ' ', 0)
+			fmt.Fprintln(tw, "NAME\tACCESS\tOWNER\tEMBEDDED BY")
+			for _, x := range cs {
+				access := "read"
+				if x.Writable {
+					access = "read, write"
+				}
+				fmt.Fprintf(tw, "%s\t%s\t%s\t%s (%d)\n", x.Name, access, or(x.OwnerName, x.Owner), x.EmbedModel, x.Dims)
+			}
+			return tw.Flush()
+		},
+	}
+}
+
+func syncCmd(g *globalFlags) *cobra.Command {
+	var o kbsync.Options
+	var verbose bool
+	var ocr string
+	var maxMiB int64
+	cmd := &cobra.Command{
+		Use:   "sync COLLECTION PATH...",
+		Short: "Send a collection what changed in these folders and files",
+		Long: `Reads the files under each PATH that the collection does not already have as
+they are, and sends their text and vectors. Run it again whenever you like;
+unchanged files are not even read.
+
+Documents are named by their path under PATH, with forward slashes; with
+several PATHs, each folder's own name comes first.
+
+  --dry-run   reads and cuts everything, sends nothing, and says what would
+              leave this machine
+  --delete    removes documents this machine sent whose files are gone
+              (only under these PATHs; nothing anybody else sent)
+  --retry     reads again files skipped before (after installing LibreOffice
+              or Tesseract, say)
+
+Without --include, every file of a known format is read (llmgw-kb formats);
+hidden files, version control folders and Office lock files are not.`,
+		Args: cobra.MinimumNArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			c, err := client(g)
+			if err != nil {
+				return err
+			}
+			ctx, stop := signal.NotifyContext(cmd.Context(), os.Interrupt)
+			defer stop()
+			l, err := g.openLedger(ctx)
+			if err != nil {
+				return err
+			}
+			defer l.Close()
+			o.Collection, o.Roots = args[0], args[1:]
+			o.Extract = extract.Options{Helpers: extract.FindHelpers(), OCRLanguages: ocr, MaxBytes: maxMiB << 20}
+			out := cmd.OutOrStdout()
+			c.Waiting = func(why string, d time.Duration) {
+				fmt.Fprintf(out, "  ..       waiting %s: %s\n", d, why)
+			}
+			start := time.Now()
+			rep, err := kbsync.Sync(ctx, c, l, o, func(e kbsync.Event) {
+				switch e.Kind {
+				case "unchanged":
+					if !verbose {
+						return
+					}
+					fmt.Fprintf(out, "  =        %s\n", e.Name)
+				case "sent", "would-send":
+					fmt.Fprintf(out, "  %-8s %s (%d chunks, %s)\n", label(e.Kind), e.Name, e.Chunks, size(e.Bytes))
+				default:
+					line := fmt.Sprintf("  %-8s %s", label(e.Kind), e.Name)
+					if e.Detail != "" {
+						line += ": " + e.Detail
+					}
+					fmt.Fprintln(out, line)
+				}
+			})
+			if rep.Collection.Name != "" {
+				verb := "sent"
+				if o.DryRun {
+					verb = "would send"
+				}
+				fmt.Fprintf(out, "\n%s: %d files; %s %d (%d chunks, %s), %d unchanged, %d skipped, %d failed, %d deleted, in %s\n",
+					rep.Collection.Name, rep.Files, verb, rep.Sent, rep.Chunks, size(rep.Bytes), rep.Unchanged,
+					rep.Skipped, rep.Failed, rep.Deleted, time.Since(start).Round(time.Second))
+			}
+			if err != nil {
+				return err
+			}
+			if rep.Failed > 0 {
+				return fmt.Errorf("%d document(s) failed; run again to retry them", rep.Failed)
+			}
+			return nil
+		},
+	}
+	f := cmd.Flags()
+	f.StringSliceVar(&o.Include, "include", nil, "read only files matching these globs (\"*.pdf,docs/**/*.md\")")
+	f.StringSliceVar(&o.Exclude, "exclude", nil, "never read files matching these globs")
+	f.BoolVar(&o.Hidden, "hidden", false, "read hidden files and folders too")
+	f.BoolVar(&o.DryRun, "dry-run", false, "send nothing; say what would be sent")
+	f.BoolVar(&o.Delete, "delete", false, "remove documents this machine sent whose files are gone")
+	f.BoolVar(&o.Retry, "retry", false, "read again files skipped before")
+	f.IntVar(&o.Workers, "workers", 4, "files read and sent at once")
+	f.StringVar(&ocr, "ocr-languages", "tur+eng", "Tesseract's languages for images and scanned pages")
+	f.Int64Var(&maxMiB, "max-size", 256, "skip files larger than this many MiB")
+	f.BoolVarP(&verbose, "verbose", "v", false, "list unchanged files too")
+	return cmd
+}
+
+func label(kind string) string {
+	switch kind {
+	case "would-send":
+		return "send"
+	case "would-delete":
+		return "delete"
+	}
+	return kind
+}
+
+func size(b int64) string {
+	switch {
+	case b >= 1<<20:
+		return fmt.Sprintf("%.1f MiB", float64(b)/(1<<20))
+	case b >= 1<<10:
+		return fmt.Sprintf("%.0f KiB", float64(b)/(1<<10))
+	}
+	return fmt.Sprintf("%d B", b)
+}
+
+func statusCmd(g *globalFlags) *cobra.Command {
+	var all bool
+	return &cobra.Command{
+		Use:   "status COLLECTION",
+		Short: "Show what this machine has sent to a collection, and what it skipped",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			c, err := client(g)
+			if err != nil {
+				return err
+			}
+			m, err := c.Manifest(cmd.Context(), args[0])
+			if err != nil {
+				return err
+			}
+			l, err := g.openLedger(cmd.Context())
+			if err != nil {
+				return err
+			}
+			defer l.Close()
+			es, err := l.Entries(cmd.Context(), strings.TrimRight(c.Base, "/"), m.Collection.ID)
+			if err != nil {
+				return err
+			}
+			counts := map[kbsync.State]int{}
+			tw := tabwriter.NewWriter(cmd.OutOrStdout(), 2, 4, 2, ' ', 0)
+			fmt.Fprintln(tw, "STATE\tDOCUMENT\tCHUNKS\tWHEN\tWHY")
+			for _, e := range es {
+				counts[e.State]++
+				if e.State == kbsync.Sent && !all {
+					continue
+				}
+				fmt.Fprintf(tw, "%s\t%s\t%d\t%s\t%s\n", e.State, e.Name, e.Chunks, e.At.Format("2006-01-02 15:04"), e.Reason)
+			}
+			_ = tw.Flush()
+			fmt.Fprintf(cmd.OutOrStdout(), "\n%s holds %d documents; from this machine %d sent, %d skipped, %d failed.",
+				m.Collection.Name, len(m.Documents), counts[kbsync.Sent], counts[kbsync.Skipped], counts[kbsync.Failed])
+			if !all {
+				fmt.Fprint(cmd.OutOrStdout(), " (--all lists the sent ones too)")
+			}
+			fmt.Fprintln(cmd.OutOrStdout())
+			return nil
+		},
+	}
+}
+
+func historyCmd(g *globalFlags) *cobra.Command {
+	return &cobra.Command{
+		Use:   "history",
+		Short: "List the latest syncs from this machine",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			l, err := g.openLedger(cmd.Context())
+			if err != nil {
+				return err
+			}
+			defer l.Close()
+			runs, err := l.Runs(cmd.Context(), 20)
+			if err != nil {
+				return err
+			}
+			tw := tabwriter.NewWriter(cmd.OutOrStdout(), 2, 4, 2, ' ', 0)
+			fmt.Fprintln(tw, "STARTED\tTOOK\tCOLLECTION\tSENT\tUNCHANGED\tSKIPPED\tFAILED\tDELETED")
+			for _, r := range runs {
+				took := "unfinished"
+				if !r.Finished.IsZero() {
+					took = r.Finished.Sub(r.Started).Round(time.Second).String()
+				}
+				fmt.Fprintf(tw, "%s\t%s\t%s\t%d\t%d\t%d\t%d\t%d\n", r.Started.Format("2006-01-02 15:04"), took,
+					r.Collection, r.Sent, r.Unchanged, r.Skipped, r.Failed, r.Delete)
+			}
+			return tw.Flush()
+		},
+	}
+}
+
+func formatsCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "formats",
+		Short: "List the formats read, and the helpers found on this machine",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			builtIn, helper := extract.Supported()
+			out := cmd.OutOrStdout()
+			fmt.Fprintf(out, "Read here:\n%s\n\n", wrap(builtIn))
+			fmt.Fprintf(out, "Read with a helper program:\n%s\n\n", wrap(helper))
+			fmt.Fprintln(out, "Helpers:")
+			for _, l := range extract.FindHelpers().Describe() {
+				fmt.Fprintln(out, "  "+l)
+			}
+			return nil
+		},
+	}
+}
+
+func wrap(words []string) string {
+	var b strings.Builder
+	line := "  "
+	for _, w := range words {
+		if len(line)+len(w) > 78 {
+			b.WriteString(strings.TrimRight(line, " ") + "\n")
+			line = "  "
+		}
+		line += w + " "
+	}
+	b.WriteString(strings.TrimRight(line, " "))
+	return b.String()
+}

cmd/llmgw-kb/main_test.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+// The client goes onto employees' laptops: none of the server, agent, store
+// or setup code may come with it, and it must build where llmgw does not.
+func TestTheClientCarriesNoServerCode(t *testing.T) {
+	out, err := exec.Command("go", "list", "-deps", ".").Output()
+	if err != nil {
+		t.Skipf("go list: %v", err)
+	}
+	for _, dep := range strings.Fields(string(out)) {
+		for _, banned := range []string{"/internal/store", "/internal/router", "/internal/agent", "/internal/control",
+			"/internal/cli", "/internal/guard", "github.com/jackc/pgx"} {
+			if strings.Contains(dep, banned) {
+				t.Errorf("llmgw-kb depends on %s", dep)
+			}
+		}
+	}
+}

docs.go

@@ -39,7 +39,7 @@ func (d Doc) Source() string {
 // than with either reader, because the console's manual and the gateway's
 // docs portal both list them, and two lists drift.
 var docOrder = []string{"console", "quick-install", "install", "node-onboarding", "onboarding",
-	"clients", "guardrails", "choosing-models", "fabrics", "facility-aware-placement", "data",
+	"clients", "guardrails", "knowledge", "choosing-models", "fabrics", "facility-aware-placement", "data",
 	"reference", "development"}
 
 // Manual is every document, in reading order: those docOrder names, then any

docs/admin-api.openapi.json

@@ -53,6 +53,9 @@
     {
       "name": "jobs"
     },
+    {
+      "name": "kb"
+    },
     {
       "name": "metrics"
     },
@@ -1069,6 +1072,381 @@
         }
       }
     },
+    "/api/v1/kb": {
+      "get": {
+        "operationId": "getKb",
+        "summary": "Every knowledge-base collection, with its documents' count and grants",
+        "description": "Says why there are none when the store cannot hold them (SQLite, or PostgreSQL without pgvector).",
+        "tags": [
+          "kb"
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/KBView"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/collections": {
+      "post": {
+        "operationId": "postKbCollections",
+        "summary": "Make a collection, owned by an organization, team, project or person",
+        "description": "The embedding model's dimension is asked of the model when dims is not given, so the model must be able to serve.",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/KBCreateRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/KBCollectionView"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/collections/{id}": {
+      "delete": {
+        "operationId": "deleteKbCollectionsId",
+        "summary": "Remove a collection with its documents and grants",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "description": "The collection's ID, its name when that is unique, or ORG/NAME.",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "additionalProperties": {}
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/collections/{id}/documents": {
+      "get": {
+        "operationId": "getKbCollectionsIdDocuments",
+        "summary": "A collection's documents",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "description": "The collection's ID, its name when that is unique, or ORG/NAME.",
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/components/schemas/KBDocumentView"
+                  }
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      },
+      "delete": {
+        "operationId": "deleteKbCollectionsIdDocuments",
+        "summary": "Remove one document from a collection",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "description": "The collection's ID, its name when that is unique, or ORG/NAME.",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "name": "name",
+            "in": "query",
+            "required": true,
+            "description": "The document's name, as listed.",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "additionalProperties": {}
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/defaults": {
+      "post": {
+        "operationId": "postKbDefaults",
+        "summary": "Set the collections a part of the tree answers from when a request names none",
+        "description": "On an organization, team, project or key; the narrowest one with a default wins. No collections clears it. A request's own X-Llmgw-Knowledge overrides it, and X-Llmgw-Knowledge: none turns it off.",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/KBDefaultRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/KBDefaultView"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/grants": {
+      "post": {
+        "operationId": "postKbGrants",
+        "summary": "Let a scope, and everything below it, read or write a collection",
+        "description": "Never outside the collection's organization.",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/KBGrantRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/KBGrantView"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      },
+      "delete": {
+        "operationId": "deleteKbGrants",
+        "summary": "Take a grant away",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/KBGrantRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/KBGrantView"
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/api/v1/kb/search": {
+      "post": {
+        "operationId": "postKbSearch",
+        "summary": "Try a search of a collection, as an administrator",
+        "description": "No tenancy applies: this is for checking what a collection holds and finds.",
+        "tags": [
+          "kb"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/Actor"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/KBSearchRequest"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/components/schemas/KBHitView"
+                  }
+                }
+              }
+            }
+          },
+          "401": {
+            "$ref": "#/components/responses/Unauthorized"
+          },
+          "default": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
     "/api/v1/metrics/range": {
       "post": {
         "operationId": "postMetricsRange",
@@ -4606,6 +4984,249 @@
           }
         }
       },
+      "KBCollectionView": {
+        "type": "object",
+        "description": "KBCollectionView is a collection as an administrator sees it.",
+        "properties": {
+          "id": {
+            "type": "string"
+          },
+          "name": {
+            "type": "string"
+          },
+          "org": {
+            "type": "string"
+          },
+          "org_name": {
+            "type": "string"
+          },
+          "owner": {
+            "type": "string"
+          },
+          "owner_name": {
+            "type": "string"
+          },
+          "embed_model": {
+            "type": "string"
+          },
+          "dims": {
+            "type": "integer"
+          },
+          "documents": {
+            "type": "integer"
+          },
+          "chunks": {
+            "type": "integer"
+          },
+          "grants": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/KBGrantView"
+            },
+            "description": "Grants are who else may read or write it."
+          },
+          "created_at": {
+            "type": "string",
+            "format": "date-time"
+          },
+          "created_by": {
+            "type": "string"
+          }
+        }
+      },
+      "KBCreateRequest": {
+        "type": "object",
+        "description": "KBCreateRequest makes a collection.",
+        "properties": {
+          "owner": {
+            "type": "string",
+            "description": "Owner is org:NAME, team:ORG/TEAM, project:ORG/TEAM/PROJECT (or the ID after the colon), or user:USER-ID."
+          },
+          "org": {
+            "type": "string",
+            "description": "Org is the organization a person's collection belongs to; only for user: owners."
+          },
+          "name": {
+            "type": "string"
+          },
+          "model": {
+            "type": "string",
+            "description": "Model is the catalog model that embeds its documents."
+          },
+          "dims": {
+            "type": "integer",
+            "description": "Dims is the model's embedding dimension; asked of the model when 0."
+          }
+        }
+      },
+      "KBDefaultRequest": {
+        "type": "object",
+        "description": "KBDefaultRequest sets the collections a part of the tree answers from when a request names none; none clears it.",
+        "properties": {
+          "target": {
+            "type": "string",
+            "description": "Target is org:, team:, project: (by path or ID) or key:KEY-ID."
+          },
+          "collections": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            },
+            "description": "Collections are IDs, names when unique, or ORG/NAME."
+          }
+        }
+      },
+      "KBDefaultView": {
+        "type": "object",
+        "description": "KBDefaultView is one part of the tree's default collections.",
+        "properties": {
+          "target": {
+            "type": "string"
+          },
+          "name": {
+            "type": "string"
+          },
+          "collections": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            },
+            "description": "Collections are ORG/NAME, in order."
+          },
+          "at": {
+            "type": "string",
+            "format": "date-time"
+          },
+          "by": {
+            "type": "string"
+          }
+        }
+      },
+      "KBDocumentView": {
+        "type": "object",
+        "description": "KBDocumentView is one document in a collection.",
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "digest": {
+            "type": "string"
+          },
+          "bytes": {
+            "type": "integer",
+            "format": "int64"
+          },
+          "chunks": {
+            "type": "integer"
+          },
+          "added_at": {
+            "type": "string",
+            "format": "date-time"
+          },
+          "added_by": {
+            "type": "string"
+          }
+        }
+      },
+      "KBGrantRequest": {
+        "type": "object",
+        "description": "KBGrantRequest lets a scope read or write a collection, or with DELETE takes that away.",
+        "properties": {
+          "collection": {
+            "type": "string",
+            "description": "Collection is its ID, its name when that is unique, or ORG/NAME."
+          },
+          "target": {
+            "type": "string",
+            "description": "Target is org:, team:, project:, key: or user: as for guard policies."
+          },
+          "perm": {
+            "type": "string",
+            "description": "Perm is read or write; ignored by DELETE."
+          }
+        }
+      },
+      "KBGrantView": {
+        "type": "object",
+        "description": "KBGrantView is one grant.",
+        "properties": {
+          "target": {
+            "type": "string"
+          },
+          "name": {
+            "type": "string"
+          },
+          "perm": {
+            "type": "string"
+          },
+          "at": {
+            "type": "string",
+            "format": "date-time"
+          },
+          "by": {
+            "type": "string"
+          }
+        }
+      },
+      "KBHitView": {
+        "type": "object",
+        "description": "KBHitView is one chunk a search found.",
+        "properties": {
+          "document": {
+            "type": "string"
+          },
+          "ord": {
+            "type": "integer"
+          },
+          "score": {
+            "type": "number"
+          },
+          "text": {
+            "type": "string"
+          }
+        }
+      },
+      "KBSearchRequest": {
+        "type": "object",
+        "description": "KBSearchRequest tries a search, as an administrator: no tenancy applies.",
+        "properties": {
+          "collection": {
+            "type": "string"
+          },
+          "query": {
+            "type": "string"
+          },
+          "k": {
+            "type": "integer"
+          }
+        }
+      },
+      "KBView": {
+        "type": "object",
+        "description": "KBView is every collection, or why there can be none.",
+        "properties": {
+          "available": {
+            "type": "boolean"
+          },
+          "reason": {
+            "type": "string",
+            "description": "Reason is why not, when not."
+          },
+          "collections": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/KBCollectionView"
+            }
+          },
+          "defaults": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/KBDefaultView"
+            },
+            "description": "Defaults are the collections parts of the tree answer from when a request names none."
+          }
+        }
+      },
       "Live": {
         "type": "object",
         "description": "Live is one of the cluster's adapters as its node last reported it.",

docs/console.md

@@ -164,6 +164,15 @@ which): requests, tokens, errors and spend.
 team or project is guaranteed and may at most hold, and what it holds now.
 **A** adds one; on a row, change or remove it.
 
+**Knowledge** lists the knowledge-base collections: each one's owner, the
+model that embeds it, how many documents and chunks it holds and who else it
+is granted to. **A** makes one. On a row: its **Documents**, **Grant…** a
+project, team, organization, person or key read or write access, **Revoke**
+a grant, **Answer from it by default…** for a part of the tree, **Try a
+search…** as an administrator, or **Delete…** it. People
+fill collections from their own machines with `llmgw-kb`
+([knowledge.md](knowledge.md)). Off on a SQLite store, and says why.
+
 **Mirror** is what the model mirror holds, one row for each version of each
 model — a file, or the set of files a model of several is: shards, a vision
 projector, a config and tokenizer — with how far its download has got and

docs/install.md

@@ -258,8 +258,14 @@ llmgw ctl config history                 # who changed what, when, and why
 llmgw ctl config rollback 4              # back to version 4, as a new version
 ```
 
-or on the console's **Settings** screen. A change is checked before it is
-kept — one that would not load is refused — and recorded in the audit log.
+or on the console's **Settings** screen, or in a browser on the portal's
+**Settings** page (`/admin/settings`, for administrators only: the document
+can hold webhook secrets). The page edits the same document, lists its
+history, and puts an earlier version back. A change is checked before it is
+kept, so one that would not load is refused. A change made from a version
+someone else has replaced since is refused too, rather than overwriting
+theirs. Every change is recorded in the audit log, with the document's size
+but not its contents.
 Guardrails change live; anything else has every control plane start again on
 the new settings, the standbys first and the leader half a minute later, so
 one of them is always serving. Engines keep running through it.
@@ -269,6 +275,33 @@ cluster keys — with a `baseline` guard policy, if the file had none — and
 from then on those keys in any server.yaml are not read (the server says so
 when it starts).
 
+**The nodes' agents** are set the same way, under `agents`. `agents.default`
+is for every node, and `agents.nodes.<node-id>` is for one node, laid over
+the default:
+
+```
+llmgw ctl config set agents.default.heartbeat_interval 5s
+llmgw ctl config set agents.nodes.cuda01.labels.gpu rtx6000
+llmgw ctl config edit                    # fabrics, engines, supervisor, discovery…
+```
+
+Each node's `agent.yaml` then needs only what its agent must know before it
+can be told anything: `node_id`, `server` or `servers`, `hostname`,
+`mgmt_addr` and `tls`. Those keys are refused under `agents`.
+
+- **Precedence.** Anything else in the file is still read, with the
+  cluster's settings over it.
+- **Applying a change.** The control plane sends each node its settings, a
+  second apart. An agent whose settings changed keeps them beside its
+  `agent.yaml` (in `/var/lib/llmgw-agent/agent-settings.yaml`) and starts
+  again on them, its engines serving throughout.
+- **Bad settings.** Settings that would not load are refused when they are
+  saved. If they somehow do not load beside one node's own file, that agent
+  keeps running on what it has and logs why.
+- **Editing `agent.yaml` itself.** The agent notices the change within ten
+  seconds and starts again on it. If the edited file does not load, the
+  agent reports it and keeps running on what it had.
+
 **This machine's own keys** stay in `/etc/llmgw/server.yaml`: `listen`,
 `admin_listen`, `metrics_listen`, `agent_listen`, `agent_tls`, `auth.store`,
 `secrets`, `tracing`, `monitoring`, `mirror.api` and `mirror.tls`, the backup

docs/knowledge.md

@@ -0,0 +1,349 @@
+# Knowledge bases
+
+A knowledge base is a collection of a company's documents that the cluster
+can answer from. People put their documents into it from their own machines
+with `llmgw-kb`. The tool reads the files on that machine, cuts them into
+passages ("chunks"), has the gateway embed each passage with the person's own
+key, and sends the text and the vectors. The files themselves never leave
+the machine.
+
+## Why retrieval, and not training
+
+Retrieval is the tool for *knowledge*: policies, procedures, contracts. The
+answer can name its source, a changed document is sent again in minutes, and
+a passage only ever reaches people allowed to read its collection.
+
+Training a model on the documents (LoRA) changes how it *writes*, not what it
+reliably *knows*. It has no access control: whatever goes into the weights
+is available to everyone who may use them.
+
+## What it needs
+
+- **The PostgreSQL store with pgvector.** On a SQLite store knowledge bases
+  are off, and `llmgw ctl kb list` and the console say why.
+  - `llmgw server init` and the high-availability database setup install
+    pgvector and enable it.
+  - A cluster set up before this build needs it by hand, once:
+    1. Install the package on every database machine:
+       `sudo apt-get install postgresql-16-pgvector` (use the server's
+       version number).
+    2. On the leader, enable it in llmgw's database:
+       `sudo -u postgres psql -d llmgw -c 'CREATE EXTENSION vector'`.
+    3. Restart the control planes: `llmgw restart`.
+- **An embedding model in the catalog**, with `capabilities.embeddings`.
+  Two good choices handle Turkish and run on CPUs: `BAAI/bge-m3` (1024
+  dimensions) and `Qwen/Qwen3-Embedding-0.6B`.
+
+  Add it as any model is added (**Serve a model** in the console, or the
+  catalog), with its entry saying that it embeds:
+
+  ```yaml
+  capabilities:
+    embeddings: true
+  ```
+
+  A collection stays with the model it was made with: vectors from two
+  models cannot be compared.
+
+## For administrators
+
+### Make a collection
+
+A collection belongs to one part of the tenancy tree: an organization, a
+team, a project or a person. Whoever is in the owner, at any level below it,
+may read it and add to it.
+
+```sh
+llmgw ctl kb create team:Acme/hr policies bge-m3
+llmgw ctl kb create user:USER-ID notes bge-m3 --org Acme
+```
+
+The model's dimension is asked of the model itself, so the model has to be
+able to serve when the collection is made. `--dims 1024` gives it instead.
+
+In the console: **Knowledge**, then **A**.
+
+### Who may read and add
+
+The owner, and everything below it, may read and add. A **grant** gives the
+same to another part of the same organization, to a person, or to one key:
+
+```sh
+llmgw ctl kb grant Acme/policies project:Acme/sales/crm           # read
+llmgw ctl kb grant Acme/policies team:Acme/legal --write          # read and add
+llmgw ctl kb revoke Acme/policies project:Acme/sales/crm
+```
+
+How access works:
+
+- **Grants add up down the tree.** A grant to a team reaches its projects
+  and their keys.
+- **Nothing crosses organizations.** A grant to another organization's
+  team, project, key or person is refused.
+- **A person's own key** (a key with no project) reads nothing by itself.
+  The person names the project they act in (`llmgw-kb login` asks for it,
+  or `--project`) and must be a member of it. Joining a second team
+  therefore does not quietly widen what every key of theirs can read.
+- **No access looks like no collection.** A collection a key may not read
+  is answered exactly as one that does not exist, so even its name does not
+  leak.
+
+### Answer from collections by default
+
+Clients that cannot add a header still get answers from the documents when
+their part of the tree has a default:
+
+```sh
+llmgw ctl kb default team:Acme/hr Acme/policies Acme/forms
+llmgw ctl kb default key:KEY-ID Acme/policies
+llmgw ctl kb default team:Acme/hr --clear
+```
+
+- **Which default applies.** The narrowest one: a key's over its project's,
+  a project's over its team's, a team's over its organization's.
+- **A request can override it.** A request that names collections uses
+  those instead, and `X-Llmgw-Knowledge: none` turns the default off for
+  that request.
+- **A default never refuses a request.** A collection the caller may not
+  read is left out for them. If the search fails (the embedding model is
+  down, say), the request is answered without passages and the failure is
+  logged.
+- **Changes take effect within 30 seconds.**
+
+In the console: **Knowledge**, Enter on a collection, then **Answer from it
+by default…**.
+
+### Look after it
+
+```sh
+llmgw ctl kb list                          # collections, owners, documents, grants
+llmgw ctl kb docs Acme/policies            # its documents, who added each and when
+llmgw ctl kb rm Acme/policies old/form.pdf # one document out
+llmgw ctl kb search Acme/policies how many days of annual leave
+llmgw ctl kb delete Acme/policies          # the collection, its documents and grants
+```
+
+Rules that apply:
+
+- A project, team or organization that owns a collection is not deleted
+  until its collections are. This is the same rule as for one with members.
+- A person's own collections go with their account (`users delete`,
+  `users forget`).
+- Every document added or removed is in the audit log (`llmgw ctl audit`),
+  by name. The text is never recorded.
+
+## For everyone: `llmgw-kb`
+
+### Get it
+
+Download `llmgw-kb` for your system from the release page, next to `llmgw`:
+
+| System | File |
+|---|---|
+| Windows (Intel/AMD) | `llmgw-kb-VERSION-windows-amd64.exe` |
+| Windows (ARM) | `llmgw-kb-VERSION-windows-arm64.exe` |
+| macOS (Apple silicon) | `llmgw-kb-VERSION-darwin-arm64` |
+| macOS (Intel) | `llmgw-kb-VERSION-darwin-amd64` |
+| Linux | `llmgw-kb-VERSION-linux-amd64` / `-arm64` |
+
+Rename it to `llmgw-kb` (`llmgw-kb.exe` on Windows) and put it somewhere on
+your PATH. You do not need to install anything else.
+
+On macOS, a downloaded program that is not signed is stopped the first time.
+Either right-click it and choose Open, or run
+`xattr -d com.apple.quarantine llmgw-kb`.
+
+### Log in once
+
+```sh
+llmgw-kb login
+```
+
+It asks for three things, checks them, and saves them where only you can
+read them:
+
+- **The gateway's address.**
+- **Your API key.** It is typed without being shown.
+- **A project.** Needed only for a personal key.
+
+Instead of logging in you can set `LLMGW_URL`, `LLMGW_API_KEY` and
+`LLMGW_PROJECT`.
+
+```sh
+llmgw-kb collections        # what your key may read, and which you may add to
+```
+
+### Send your documents
+
+```sh
+llmgw-kb sync policies ~/Documents/HR
+llmgw-kb sync policies "C:\Users\ayse\Documents\İK" --include "*.pdf,*.docx"
+llmgw-kb sync policies ./handbook ./forms --exclude "drafts/**"
+```
+
+Run it as often as you like. The first run sends everything. Later runs
+send only what changed, and do not even read files whose size and time have
+not changed.
+
+| Option | What it does |
+|---|---|
+| `--dry-run` | Reads and cuts everything, sends nothing, and lists what would leave the machine and how much. |
+| `--delete` | Also removes documents whose files are gone. Only those this machine sent, from these folders; never anything someone else sent. |
+| `--retry` | Reads again files skipped before, for example after installing LibreOffice. |
+| `--include`, `--exclude` | Glob patterns. `*.pdf` matches a file name; `reports/**/*.xlsx` matches a path. |
+| `--hidden` | Reads hidden files and folders too (left out by default). |
+| `-v` | Lists unchanged files too. |
+
+Documents are named by their path under the folder, with forward slashes,
+on every system. With several folders, each folder's own name comes first.
+
+```sh
+llmgw-kb status policies    # what this machine sent and skipped, and why
+llmgw-kb history            # the latest runs
+llmgw-kb formats            # what can be read here
+```
+
+### What it reads
+
+| Read here | Formats |
+|---|---|
+| Documents | PDF (text), Word (`.docx`), Excel (`.xlsx`), PowerPoint (`.pptx`, with speaker notes), OpenDocument (`.odt`, `.ods`, `.odp`), RTF, EPUB |
+| Web and mail | HTML, MHTML, e-mail (`.eml`, with its attachments) |
+| Text | Markdown, plain text, CSV, JSON, YAML, XML, subtitles, notebooks (`.ipynb`), source code |
+| Archives | ZIP, with every file inside it read in turn |
+
+| Read with a helper on your machine | Helper |
+|---|---|
+| Word, Excel and PowerPoint 97–2003 (`.doc`, `.xls`, `.ppt`), Pages, Numbers, Keynote and others | [LibreOffice](https://www.libreoffice.org) |
+| Images and scanned PDFs | [Tesseract](https://tesseract-ocr.github.io) (with the Turkish language data), plus Poppler's `pdftoppm` for PDFs |
+| PDFs the built-in reader cannot parse | Poppler's `pdftotext` |
+
+`llmgw-kb formats` says which helpers it found. Text in UTF-8, UTF-16, or
+the Windows Turkish and Western code pages is read correctly.
+
+A file that cannot be read is skipped with the reason, and the run goes on.
+Reasons include a locked Office file, a format with no helper, and a
+scanned page with no OCR.
+
+### What leaves your machine
+
+For each new or changed document, two things leave the machine, both over
+the gateway's TLS connection:
+
+- **The passages, to be embedded.** They go through `/v1/embeddings` like
+  any request of yours. Your key's limits, budget and guardrails apply.
+- **The document itself.** Its name, its file's SHA-256 digest and size,
+  and the passages with their vectors.
+
+The file itself is never sent. `--dry-run` shows exactly what would be.
+
+### The ledger
+
+`llmgw-kb` keeps a small SQLite database of what it did with every
+document: the file it came from, its size, time and digest, and whether it
+was sent, skipped or failed, with the reason.
+
+| System | Where it is |
+|---|---|
+| Windows | `%AppData%\llmgw-kb\ledger.db` |
+| macOS | `~/Library/Application Support/llmgw-kb/ledger.db` |
+| Linux | `~/.config/llmgw-kb/ledger.db` |
+
+Deleting the ledger is safe: the next run hashes every file once, finds what
+the collection already has, and sends nothing that is unchanged. `--ledger`
+uses another file.
+
+## Asking questions of a collection
+
+A chat request names the collections to answer from in a header. Any client
+that can add a header can do it: the OpenAI and Anthropic SDKs, Continue, or
+curl.
+
+```sh
+curl https://llm.example.com/v1/chat/completions \
+  -H "Authorization: Bearer $LLMGW_API_KEY" \
+  -H "X-Llmgw-Knowledge: politikalar" \
+  -d '{"model": "qwen2.5-coder-14b-instruct",
+       "messages": [{"role": "user", "content": "Kaç gün yıllık iznim var?"}]}'
+```
+
+```python
+client.chat.completions.create(
+    model="qwen2.5-coder-14b-instruct",
+    messages=[{"role": "user", "content": "Kaç gün yıllık iznim var?"}],
+    extra_headers={"X-Llmgw-Knowledge": "politikalar"},
+)
+```
+
+What the gateway does with such a request:
+
+1. **It finds the collections.** It looks up the ones named, by name or ID,
+   among those the key may read. A collection it may not read is answered
+   404, the same as one that does not exist.
+2. **It embeds the question.** The last user message is embedded by the
+   collection's model, on the caller's own account: their limits, budget and
+   guardrails apply.
+3. **It searches.** The collections are searched by meaning and by words
+   (below).
+4. **It adds the passages.** The best passages are numbered and added to the
+   system message, with an instruction to answer from them, cite them as
+   [1], [2], and say so when they do not hold the answer. The system message
+   is created if the request has none. Passages that would not fit the
+   model's context are left out, the weakest first.
+5. **It judges and sends the request.** The request, passages included, then
+   goes through the guardrails and to the model as usual. A document
+   carrying instructions aimed at its reader is judged like anything else
+   the model reads.
+
+On the portal's chat page, **Documents** picks a collection the person may
+read in the chosen project, the default, or none. Under each answer, the
+sources it was given are listed by number.
+
+How it is shaped:
+
+| | |
+|---|---|
+| `X-Llmgw-Knowledge` | Collections, comma separated; `none` for no passages, whatever the default. |
+| `X-Llmgw-Knowledge-K` | How many passages, 1 to 20; 5 by default. |
+| `X-Llmgw-Project` | For a personal key: the project it acts in. |
+| `x-llmgw-sources` (answer) | The passages given, as `document#chunk`, in their numbered order; empty when nothing matched. |
+
+Behaviour to know about:
+
+- **No passages matched.** The model is told that nothing in the documents
+  answers the question, and asked to say so rather than answer from general
+  knowledge.
+- **Other APIs.** Requests through `/v1/responses` and `/v1/messages`
+  (Codex, Claude Code) work the same way, since they are answered as chat
+  completions.
+- **Separate prefix caches.** On vLLM replicas, a request given passages
+  carries a `cache_salt` derived from its organization. One organization's
+  passages then never share cached blocks with another's, so how fast an
+  answer starts says nothing about what another tenant asked.
+- **No answer cache.** Answers from knowledge bases are never served from
+  the answer cache, because two keys of one project can read different
+  collections.
+
+### How a passage is chosen
+
+Each passage scores the following, and the highest scores win:
+
+- its similarity in meaning to the question (cosine, 0 to 1), plus
+- up to 0.3 for the share of the question's words it contains.
+
+Words almost every passage has ("ne", "için", "the", "of") are not counted.
+The meaning does most of the work: "how much leave do fathers get" finds the
+paternity page, not the annual-leave page that shares more of its words.
+The word match helps with what meaning cannot carry, such as a form number,
+a product code or a name.
+
+Metrics: `llmgw_kb_retrievals_total{result}` (found, nothing, refused) and
+`llmgw_kb_retrieval_seconds`.
+
+## How it is kept apart
+
+Passages live in PostgreSQL, partitioned by organization, with an index per
+collection. Every search and every write names the organization and the
+collections the caller may use. On top of that, row-level security on the
+table checks the same thing again, so a query that forgot its filter
+returns nothing rather than another tenant's passages.

docs/reference.md

@@ -26,6 +26,8 @@ rather than repeated.
 | `queue_capacity_per_band` | `int` | [Admission](#admission) |
 | `queue_capacity_total` | `int` | [Admission](#admission) |
 | `interval` | `time.Duration` | [Admission](#admission) |
+| `default` | `map[string]any` | [AgentSettings](#agentsettings) |
+| `nodes` | `map[string]map[string]any` | [AgentSettings](#agentsettings) |
 | `enabled` | `bool` | [Auth](#auth) |
 | `store` | `string` | [Auth](#auth) |
 | `cache_ttl` | `time.Duration` | [Auth](#auth) |
@@ -294,6 +296,7 @@ rather than repeated.
 | `mail` | `mail.Config` | [Server](#server) |
 | `serving` | `ServingSettings` | [Server](#server) |
 | `firewall` | `FirewallSettings` | [Server](#server) |
+| `agents` | `AgentSettings` | [Server](#server) |
 | `firewall_networks` | `[]string` | [Server](#server) |
 | `backup_recipients` | `[]string` | [Server](#server) |
 | `backup_copy_to` | `[]string` | [Server](#server) |
@@ -469,6 +472,21 @@ Zero takes half of all the bands' capacities together.
 
 `time.Duration`
 
+## AgentSettings
+
+### `default`
+
+`map[string]any`
+
+Default is agent.yaml's keys for every node.
+
+### `nodes`
+
+`map[string]map[string]any`
+
+Nodes are agent.yaml's keys for one node each, by node id, over
+Default.
+
 ## Auth
 
 ### `enabled`
@@ -2520,6 +2538,18 @@ Firewall turns llmgw's firewall on every machine on or off.
 
 Takes a [FirewallSettings](#firewallsettings) block.
 
+### `agents`
+
+`AgentSettings`
+
+Agents are the nodes' agent settings: agent.yaml's keys but those an
+agent needs to start, for every node (default) and for one
+(nodes.<id>). Sent to the agents as they change; an agent whose
+settings changed starts again on them, its engines serving
+throughout.
+
+Takes a [AgentSettings](#agentsettings) block.
+
 ### `firewall_networks`
 
 `[]string`

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/knadh/koanf/providers/env/v2 v2.0.1
 	github.com/knadh/koanf/providers/file v1.2.1
 	github.com/knadh/koanf/v2 v2.3.6
+	github.com/ledongthuc/pdf v0.0.0-20260907135840-6c8c28e0e8a0
 	github.com/mattn/go-isatty v0.0.24
 	github.com/prometheus/client_golang v1.24.1
 	github.com/prometheus/client_model v0.6.3
@@ -34,6 +35,7 @@ require (
 	golang.org/x/net v0.59.0
 	golang.org/x/oauth2 v0.37.0
 	golang.org/x/sync v0.23.0
+	golang.org/x/term v0.46.0
 	golang.org/x/text v0.42.0
 	google.golang.org/protobuf v1.36.12
 	modernc.org/sqlite v1.59.0

go.sum

@@ -95,6 +95,8 @@ github.com/knadh/koanf/v2 v2.3.6 h1:JoQPSJmvS4aP0xNc8xMDr5tcrkSEInL23/Il7pITAKo=
 github.com/knadh/koanf/v2 v2.3.6/go.mod h1:gRb40VRAbd4iJMYYD5IxZ6hfuopFcXBpc9bbQpZwo28=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/ledongthuc/pdf v0.0.0-20260907135840-6c8c28e0e8a0 h1:7Q+xNAZFmnfYOMweHN3c/PDFUKKfY1pVJ26K++QvVfU=
+github.com/ledongthuc/pdf v0.0.0-20260907135840-6c8c28e0e8a0/go.mod h1:1fEHWurg7pvf5SG6XNE5Q8UZmOwex51Mkx3SLhrW5B4=
 github.com/lucasb-eyer/go-colorful v1.3.0 h1:2/yBRLdWBZKrf7gB40FoiKfAWYQ0lqNcbuQwVHXptag=
 github.com/lucasb-eyer/go-colorful v1.3.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-isatty v0.0.24 h1:tGZZoVgT/KiqK1c8ocVLeDS8BSWMRd47J3Lbz7vsReI=

internal/agent/agent.go

@@ -136,6 +136,10 @@ type Agent struct {
 	// by mu.
 	kv     *kvevents.Mirror
 	kvSubs map[string]*kvevents.Subscriber
+
+	// settingsCheck says whether the cluster's settings for this agent
+	// would load beside its agent.yaml; see SetSettingsCheck.
+	settingsCheck func([]byte) error
 }
 
 // connectHTTPClient is the HTTP client connect uses; an interface so tests can
@@ -880,6 +884,8 @@ func (a *Agent) handle(ctx context.Context, msg *llmgwv1.ControlMessage, out cha
 		a.setControlPlanes(m.ControlPlanes)
 	case *llmgwv1.ControlMessage_Firewall:
 		go a.applyFirewall(m.Firewall)
+	case *llmgwv1.ControlMessage_AgentSettings:
+		go a.applySettings(m.AgentSettings)
 	case *llmgwv1.ControlMessage_RestartAgent:
 		go func() {
 			a.log.Info("restarting, as the control plane asks; the engines keep serving",

internal/agent/config.go

@@ -103,6 +103,11 @@ type Config struct {
 	Tracing obs.Tracing `koanf:"tracing"`
 
 	Version string
+
+	// Settings is the cluster's settings for this agent it was started on,
+	// as the control plane sent them: what a newly sent version is
+	// compared with.
+	Settings string `koanf:"-"`
 }
 
 // DefaultConfig returns sensible defaults.

internal/agent/settings.go

@@ -0,0 +1,109 @@
+package agent
+
+import (
+	"context"
+	"crypto/sha256"
+	"os"
+	"path/filepath"
+	"time"
+
+	llmgwv1 "gitea.mynodes.xyz/ilker/llmgw/api/gen/llmgw/v1"
+)
+
+// The cluster's settings for this agent (BACKLOG E3): what agent.yaml can
+// say but the agent's id, control planes, address and certificate, kept by
+// the control planes and sent over the stream. Kept here beside agent.yaml,
+// which then holds only what the agent needs to start; at start the two are
+// read together, these over the file.
+
+// SettingsFile keeps the settings the control plane last sent.
+var SettingsFile = "/var/lib/llmgw-agent/agent-settings.yaml"
+
+// ReadSettings is what SettingsFile holds, nil when nothing.
+func ReadSettings() []byte {
+	b, err := os.ReadFile(SettingsFile)
+	if err != nil {
+		return nil
+	}
+	return b
+}
+
+// SetSettingsCheck says how to tell whether settings would load beside this
+// agent's own file; settings that would not are not taken.
+func (a *Agent) SetSettingsCheck(f func([]byte) error) { a.settingsCheck = f }
+
+// applySettings takes the settings the control plane sent: nothing when they
+// are what this agent runs on, and otherwise kept and started again on.
+func (a *Agent) applySettings(m *llmgwv1.AgentSettings) {
+	next := m.GetYaml()
+	if next == a.cfg.Settings {
+		return
+	}
+	if a.settingsCheck != nil {
+		if err := a.settingsCheck([]byte(next)); err != nil {
+			// Kept running on what it has: settings that will not load
+			// here must not take the node out of service.
+			a.log.Error("the cluster's settings for this agent do not load beside its agent.yaml; running on what it has",
+				"err", err)
+			return
+		}
+	}
+	if err := os.MkdirAll(filepath.Dir(SettingsFile), 0o755); err != nil {
+		a.log.Error("could not keep the cluster's settings for this agent", "err", err)
+		return
+	}
+	tmp := SettingsFile + ".new"
+	if err := os.WriteFile(tmp, []byte(next), 0o600); err != nil {
+		a.log.Error("could not keep the cluster's settings for this agent", "err", err)
+		return
+	}
+	if err := os.Rename(tmp, SettingsFile); err != nil {
+		a.log.Error("could not keep the cluster's settings for this agent", "err", err)
+		return
+	}
+	a.log.Info("the cluster's settings for this agent changed; starting again on them, the engines keep serving")
+	time.Sleep(300 * time.Millisecond)
+	exitForUpgrade()
+}
+
+// WatchFile starts the agent again when its configuration file changes and
+// still loads: agent.yaml is read only at start, and a change to it that
+// waited for somebody to restart the agent was a change nobody saw take
+// effect.
+func (a *Agent) WatchFile(ctx context.Context, path string, loads func() error) {
+	if path == "" {
+		return
+	}
+	sum := func() [32]byte {
+		b, _ := os.ReadFile(path) //nolint:gosec // the agent's own configuration
+		return sha256.Sum256(b)
+	}
+	was := sum()
+	t := time.NewTicker(watchEvery)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+		}
+		now := sum()
+		if now == was {
+			continue
+		}
+		if err := loads(); err != nil {
+			// Once per change: an editor saving halfway must not stop the
+			// agent, and a broken file is reported, not restarted into.
+			a.log.Error("agent.yaml changed and does not load; running on what it had", "path", path, "err", err)
+			was = now
+			continue
+		}
+		a.log.Info("agent.yaml changed; starting again on it, the engines keep serving", "path", path)
+		time.Sleep(300 * time.Millisecond)
+		exitForUpgrade()
+		return
+	}
+}
+
+// watchEvery is how often agent.yaml is looked at.
+var watchEvery = 10 * time.Second

internal/agent/settings_test.go

@@ -0,0 +1,88 @@
+package agent
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	llmgwv1 "gitea.mynodes.xyz/ilker/llmgw/api/gen/llmgw/v1"
+)
+
+func settingsAgent(t *testing.T, running string) (*Agent, chan struct{}) {
+	t.Helper()
+	oldFile, oldExit := SettingsFile, exitForUpgrade
+	SettingsFile = filepath.Join(t.TempDir(), "agent-settings.yaml")
+	exited := make(chan struct{}, 1)
+	exitForUpgrade = func() { exited <- struct{}{} }
+	t.Cleanup(func() { SettingsFile, exitForUpgrade = oldFile, oldExit })
+	cfg := Config{Server: "127.0.0.1:7443", NodeID: "n1", WeightsCache: t.TempDir(), EnginesDir: t.TempDir(), Settings: running}
+	cfg.Superv.WorkDir = t.TempDir()
+	a, err := New(cfg, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return a, exited
+}
+
+// exitedSoon is whether the agent exited within a second: it waits a
+// moment for its log line to leave first.
+func exitedSoon(ch chan struct{}) bool {
+	select {
+	case <-ch:
+		return true
+	case <-time.After(time.Second):
+		return false
+	}
+}
+
+func TestAnAgentOnItsSettingsStaysAndOneOffThemStartsAgain(t *testing.T) {
+	a, exited := settingsAgent(t, "heartbeat_interval: 5s\n")
+	a.applySettings(&llmgwv1.AgentSettings{Yaml: "heartbeat_interval: 5s\n"})
+	if exitedSoon(exited) || ReadSettings() != nil {
+		t.Error("settings it already runs on restarted it")
+	}
+	a.applySettings(&llmgwv1.AgentSettings{Yaml: "heartbeat_interval: 2s\n"})
+	if !exitedSoon(exited) || string(ReadSettings()) != "heartbeat_interval: 2s\n" {
+		t.Errorf("new settings: kept %q", ReadSettings())
+	}
+}
+
+func TestSettingsThatWouldNotLoadAreNotTaken(t *testing.T) {
+	a, exited := settingsAgent(t, "")
+	a.SetSettingsCheck(func([]byte) error { return errors.New("fabric ib-a lists no HCAs") })
+	a.applySettings(&llmgwv1.AgentSettings{Yaml: "fabrics: [{name: ib-a}]\n"})
+	if exitedSoon(exited) || ReadSettings() != nil {
+		t.Error("settings that do not load were taken")
+	}
+}
+
+func TestAChangedAgentYamlThatLoadsStartsTheAgentAgain(t *testing.T) {
+	a, exited := settingsAgent(t, "")
+	old := watchEvery
+	watchEvery = 10 * time.Millisecond
+	t.Cleanup(func() { watchEvery = old })
+	p := filepath.Join(t.TempDir(), "agent.yaml")
+	_ = os.WriteFile(p, []byte("node_id: n1\n"), 0o600)
+	var loads atomic.Bool
+	check := func() error {
+		if loads.Load() {
+			return nil
+		}
+		return errors.New("broken")
+	}
+	go a.WatchFile(t.Context(), p, check)
+	time.Sleep(30 * time.Millisecond)
+	// Saved broken: reported, not restarted into.
+	_ = os.WriteFile(p, []byte("node_id: [\n"), 0o600)
+	if exitedSoon(exited) {
+		t.Fatal("a broken agent.yaml restarted the agent")
+	}
+	loads.Store(true)
+	_ = os.WriteFile(p, []byte("node_id: n1\nlabels: {a: b}\n"), 0o600)
+	if !exitedSoon(exited) {
+		t.Error("a changed agent.yaml did not restart the agent")
+	}
+}

internal/cli/agent.go

@@ -40,10 +40,23 @@ func newAgentCmd() *cobra.Command {
 		RunE: func(cmd *cobra.Command, _ []string) error {
 			log := logger()
 
-			cfg, err := config.LoadAgent(configPath)
+			// The cluster's settings for this agent over its file, as the
+			// control plane last sent them. Settings that no longer load
+			// beside the file are set aside rather than keeping the agent
+			// from starting: the control plane sends them again, and says
+			// why they are refused.
+			settings := agent.ReadSettings()
+			cfg, err := config.LoadAgentWith(configPath, settings)
+			if err != nil && settings != nil {
+				log.Warn("the cluster's settings kept for this agent do not load beside its agent.yaml; starting without them",
+					"err", err)
+				settings = nil
+				cfg, err = config.LoadAgent(configPath)
+			}
 			if err != nil {
 				return err
 			}
+			cfg.Settings = string(settings)
 			if server != "" {
 				cfg.Server = server
 			}
@@ -89,9 +102,17 @@ func newAgentCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
+			a.SetSettingsCheck(func(b []byte) error {
+				_, err := config.LoadAgentWith(configPath, b)
+				return err
+			})
 
 			ctx, stop := signal.NotifyContext(cmd.Context(), syscall.SIGINT, syscall.SIGTERM)
 			defer stop()
+			go a.WatchFile(ctx, configPath, func() error {
+				_, err := config.LoadAgentWith(configPath, agent.ReadSettings())
+				return err
+			})
 
 			log.Info("agent starting",
 				"node", cfg.NodeID, "server", cfg.Server,

internal/cli/clustersettings.go

@@ -241,6 +241,8 @@ var liveSettings = []string{
 	"serving",
 	// Sent to the nodes and this machine's firewall unit as they change.
 	"firewall", "firewall_networks",
+	// Sent to the nodes' agents as they change.
+	"agents",
 	// Read by server init, node add and backups, not by the server.
 	"backup_recipients", "backup_copy_to",
 }

internal/cli/ctl.go

@@ -180,6 +180,7 @@ func newCtlCmd() *cobra.Command {
 		newCapacityCmd(client, &asJSON),
 		newQuotaCmd(client, &asJSON),
 		newGuardCmd(client, &asJSON),
+		newKBCmd(client, &asJSON),
 		newConfigCmd(client, &asJSON),
 		newAuditCmd(client, &asJSON),
 		newNotifyCmd(client, &asJSON),

internal/cli/kb.go

@@ -0,0 +1,242 @@
+package cli
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/control/adminapi"
+)
+
+func newKBCmd(client func() *ctlClient, asJSON *bool) *cobra.Command {
+	c := &cobra.Command{
+		Use:   "kb",
+		Short: "Knowledge bases: collections of documents requests are answered from",
+		Long: "A collection belongs to an organization, team, project or person, and is\n" +
+			"embedded by one model of the catalog. People put documents into it from\n" +
+			"their own machines with llmgw-kb (its own download, for Windows, macOS and\n" +
+			"Linux), which sends text and vectors, never the files.\n\n" +
+			"Who may read or add to a collection: its owner and everything below it,\n" +
+			"and whoever it is granted to (grant), never outside its organization.\n" +
+			"Targets are written org:Acme, team:Acme/hr, project:Acme/hr/docs (or with\n" +
+			"IDs), key:KEY-ID or user:USER-ID. A collection is named by its ID, its name\n" +
+			"when that is unique, or ORG/NAME.\n\n" +
+			"Needs the PostgreSQL store with pgvector; `llmgw ctl kb list` says why not.",
+	}
+	c.AddCommand(&cobra.Command{
+		Use:   "list",
+		Short: "Every collection: owner, model, documents and grants",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			var v adminapi.KBView
+			if err := client().get(cmd.Context(), "/api/v1/kb", &v); err != nil {
+				return err
+			}
+			if *asJSON {
+				return json.NewEncoder(cmd.OutOrStdout()).Encode(v)
+			}
+			out := cmd.OutOrStdout()
+			if !v.Available {
+				fmt.Fprintln(out, "Knowledge bases are off: "+v.Reason)
+				return nil
+			}
+			if len(v.Collections) == 0 {
+				fmt.Fprintln(out, "No collections yet (llmgw ctl kb create).")
+				return nil
+			}
+			w := tab()
+			fmt.Fprintln(w, "COLLECTION\tOWNER\tMODEL\tDOCUMENTS\tCHUNKS\tGRANTED TO")
+			for _, c := range v.Collections {
+				var grants []string
+				for _, g := range c.Grants {
+					grants = append(grants, or(g.Name, g.Target)+" ("+g.Perm+")")
+				}
+				fmt.Fprintf(w, "%s/%s\t%s\t%s (%d)\t%d\t%d\t%s\n", or(c.OrgName, c.Org), c.Name, or(c.OwnerName, c.Owner),
+					c.EmbedModel, c.Dims, c.Documents, c.Chunks, strings.Join(grants, ", "))
+			}
+			if err := w.Flush(); err != nil {
+				return err
+			}
+			if len(v.Defaults) > 0 {
+				fmt.Fprintln(out, "\nAnswered from by default, when a request names no collection:")
+				w = tab()
+				for _, d := range v.Defaults {
+					fmt.Fprintf(w, "  %s\t%s\n", or(d.Name, d.Target), strings.Join(d.Collections, ", "))
+				}
+				return w.Flush()
+			}
+			return nil
+		},
+	})
+
+	var org string
+	var dims int
+	create := &cobra.Command{
+		Use:   "create OWNER NAME MODEL",
+		Short: "Make a collection owned by an organization, team, project or person",
+		Long: "MODEL is a catalog model with capabilities.embeddings. Its dimension is asked\n" +
+			"of it, so it has to be able to serve now; --dims gives it instead.",
+		Example: "  llmgw ctl kb create team:Acme/hr policies bge-m3\n" +
+			"  llmgw ctl kb create user:USER-ID notes bge-m3 --org Acme",
+		Args: cobra.ExactArgs(3),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			body, _ := json.Marshal(adminapi.KBCreateRequest{Owner: args[0], Name: args[1], Model: args[2], Org: org, Dims: dims})
+			var v adminapi.KBCollectionView
+			if err := client().do(cmd.Context(), "POST", "/api/v1/kb/collections", json.RawMessage(body), &v); err != nil {
+				return err
+			}
+			fmt.Fprintf(cmd.OutOrStdout(), "collection %s (%s), embedded by %s in %d dimensions\n", v.Name, v.ID, v.EmbedModel, v.Dims)
+			fmt.Fprintf(cmd.OutOrStdout(), "people with access fill it with: llmgw-kb sync %s FOLDER\n", v.Name)
+			return nil
+		},
+	}
+	create.Flags().StringVar(&org, "org", "", "the organization of a person's collection")
+	create.Flags().IntVar(&dims, "dims", 0, "the model's embedding dimension, instead of asking it")
+	c.AddCommand(create)
+
+	c.AddCommand(&cobra.Command{
+		Use:   "delete COLLECTION",
+		Short: "Remove a collection, its documents and its grants",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := client().do(cmd.Context(), "DELETE", "/api/v1/kb/collections/"+url.PathEscape(args[0]), nil, nil); err != nil {
+				return err
+			}
+			fmt.Fprintf(cmd.OutOrStdout(), "collection %s removed\n", args[0])
+			return nil
+		},
+	})
+
+	for _, verb := range []struct {
+		use, short, method string
+		perm               bool
+	}{
+		{"grant", "Let a scope and everything below it read a collection, or with --write add to it", "POST", true},
+		{"revoke", "Take a grant away", "DELETE", false},
+	} {
+		var write bool
+		cmd := &cobra.Command{
+			Use:     verb.use + " COLLECTION TARGET",
+			Short:   verb.short,
+			Example: "  llmgw ctl kb " + verb.use + " Acme/policies project:Acme/sales/crm",
+			Args:    cobra.ExactArgs(2),
+			RunE: func(cmd *cobra.Command, args []string) error {
+				req := adminapi.KBGrantRequest{Collection: args[0], Target: args[1], Perm: "read"}
+				if write {
+					req.Perm = "write"
+				}
+				body, _ := json.Marshal(req)
+				if err := client().do(cmd.Context(), verb.method, "/api/v1/kb/grants", json.RawMessage(body), nil); err != nil {
+					return err
+				}
+				if verb.perm {
+					fmt.Fprintf(cmd.OutOrStdout(), "%s may %s %s\n", args[1], req.Perm, args[0])
+				} else {
+					fmt.Fprintf(cmd.OutOrStdout(), "%s no longer granted %s\n", args[1], args[0])
+				}
+				return nil
+			},
+		}
+		if verb.perm {
+			cmd.Flags().BoolVar(&write, "write", false, "add and remove documents too")
+		}
+		c.AddCommand(cmd)
+	}
+
+	c.AddCommand(&cobra.Command{
+		Use:   "docs COLLECTION",
+		Short: "A collection's documents",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			var docs []adminapi.KBDocumentView
+			if err := client().get(cmd.Context(), "/api/v1/kb/collections/"+url.PathEscape(args[0])+"/documents", &docs); err != nil {
+				return err
+			}
+			if *asJSON {
+				return json.NewEncoder(cmd.OutOrStdout()).Encode(docs)
+			}
+			w := tab()
+			fmt.Fprintln(w, "DOCUMENT\tCHUNKS\tSIZE\tADDED\tBY")
+			for _, d := range docs {
+				fmt.Fprintf(w, "%s\t%d\t%s\t%s\t%s\n", d.Name, d.Chunks, humanBytes(d.Bytes), d.AddedAt.Local().Format("2006-01-02 15:04"), d.AddedBy)
+			}
+			return w.Flush()
+		},
+	})
+	c.AddCommand(&cobra.Command{
+		Use:   "rm COLLECTION DOCUMENT",
+		Short: "Remove one document from a collection",
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			path := "/api/v1/kb/collections/" + url.PathEscape(args[0]) + "/documents?name=" + url.QueryEscape(args[1])
+			if err := client().do(cmd.Context(), "DELETE", path, nil, nil); err != nil {
+				return err
+			}
+			fmt.Fprintf(cmd.OutOrStdout(), "%s removed from %s\n", args[1], args[0])
+			return nil
+		},
+	})
+
+	var clear bool
+	def := &cobra.Command{
+		Use:   "default TARGET [COLLECTION...]",
+		Short: "Answer a part of the tree's chat requests from collections, when they name none",
+		Long: "Requests from TARGET and everything below it are then answered from these\n" +
+			"collections without naming them (X-Llmgw-Knowledge). The narrowest default\n" +
+			"wins: a key's over its project's, a project's over its team's. A request's own\n" +
+			"header overrides it, and X-Llmgw-Knowledge: none turns it off. A collection a\n" +
+			"caller may not read is left out for them, and a search that fails answers\n" +
+			"without passages rather than refusing. In force within 30 seconds.",
+		Example: "  llmgw ctl kb default team:Acme/hr Acme/policies Acme/forms\n" +
+			"  llmgw ctl kb default team:Acme/hr --clear",
+		Args: cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if clear != (len(args) == 1) {
+				return fmt.Errorf("name collections, or --clear")
+			}
+			body, _ := json.Marshal(adminapi.KBDefaultRequest{Target: args[0], Collections: args[1:]})
+			if err := client().do(cmd.Context(), "POST", "/api/v1/kb/defaults", json.RawMessage(body), nil); err != nil {
+				return err
+			}
+			if clear {
+				fmt.Fprintf(cmd.OutOrStdout(), "%s answers from no collection by default\n", args[0])
+			} else {
+				fmt.Fprintf(cmd.OutOrStdout(), "%s answers from %s by default\n", args[0], strings.Join(args[1:], ", "))
+			}
+			return nil
+		},
+	}
+	def.Flags().BoolVar(&clear, "clear", false, "no default any more")
+	c.AddCommand(def)
+
+	var k int
+	search := &cobra.Command{
+		Use:   "search COLLECTION QUERY...",
+		Short: "Try a search of a collection, as an administrator (no tenancy applies)",
+		Args:  cobra.MinimumNArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			body, _ := json.Marshal(adminapi.KBSearchRequest{Collection: args[0], Query: strings.Join(args[1:], " "), K: k})
+			var hits []adminapi.KBHitView
+			if err := client().do(cmd.Context(), "POST", "/api/v1/kb/search", json.RawMessage(body), &hits); err != nil {
+				return err
+			}
+			if *asJSON {
+				return json.NewEncoder(cmd.OutOrStdout()).Encode(hits)
+			}
+			out := cmd.OutOrStdout()
+			if len(hits) == 0 {
+				fmt.Fprintln(out, "Nothing found.")
+			}
+			for i, h := range hits {
+				fmt.Fprintf(out, "%d. %s #%d\n%s\n\n", i+1, h.Document, h.Ord, indent(strings.TrimSpace(h.Text), "   "))
+			}
+			return nil
+		},
+	}
+	search.Flags().IntVarP(&k, "k", "k", 5, "how many chunks")
+	c.AddCommand(search)
+	return c
+}

internal/cli/server.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"crypto/tls"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"log/slog"
@@ -262,6 +263,15 @@ func newServerCmd() *cobra.Command {
 					return &llmgwv1.Firewall{Enabled: c.Firewall.Enabled, Networks: c.FirewallNetworks,
 						EnginePortsFrom: int32(from), EnginePortsTo: int32(to)} //nolint:gosec // ports
 				})
+				// What each node's agent runs on, as the settings say now.
+				svc.SetAgentSettings(func(node string) string {
+					b, err := config.Marshal(current.Load().Agents.For(node))
+					if err != nil {
+						log.Warn("could not write a node's agent settings", "node", node, "err", err)
+						return ""
+					}
+					return string(b)
+				})
 				ctl.Reconciler().SetNotifier(notifier)
 				admin = ctl
 				agentPath, agentHandler = svc.Handler()
@@ -374,10 +384,15 @@ func newServerCmd() *cobra.Command {
 						api.SetAgentRestarter(agentSvc.RestartAgents)
 					}
 					api.SetAudit(st)
+					// Knowledge bases, with the cluster's own models to embed a
+					// probe (a collection's dimension) and an operator's search.
+					api.SetKB(&adminapi.KBAdmin{Store: st, Embed: embedder(rt.Replay)})
 					// The cluster's settings, each change checked against this
 					// machine's own keys before it is kept.
 					api.SetSettings(&adminapi.Settings{Store: st, LocalKeys: config.LocalKeys(),
 						Check: func(body []byte) error { return checkClusterSettings(configPath, body) }})
+					// And the same document on the portal, for administrators.
+					rt.SetSettingsCheck(func(body []byte) error { return checkClusterSettings(configPath, body) }, config.LocalKeys())
 				}
 				// Catalog changes need somewhere to persist, so this is wired
 				// only when there is a store. Without one, the endpoints say so
@@ -713,6 +728,10 @@ func newServerCmd() *cobra.Command {
 							agentSvc.BroadcastFirewall()
 						}
 					}
+					if slices.ContainsFunc(changed, func(c string) bool { return strings.HasPrefix(c, "agents") }) && agentSvc != nil {
+						// A moment apart per node, so off this goroutine.
+						go agentSvc.BroadcastAgentSettings()
+					}
 					if slices.ContainsFunc(changed, func(c string) bool { return strings.HasPrefix(c, "guard") }) {
 						if gate == nil {
 							// Built at start, and only when there are policies.
@@ -1183,3 +1202,40 @@ func federationID(ctx context.Context, st *storepkg.DB) (string, error) {
 	// more of a secret than needed.
 	return secret[:16], nil
 }
+
+// embedder has a model embed one text through the gateway itself, the way a
+// kept request is replayed: for the administrator's knowledge-base
+// endpoints, not for anybody's traffic.
+func embedder(replay func(ctx context.Context, path, model string, body []byte) (int, []byte, time.Duration, error)) func(context.Context, string, string) ([]float32, error) {
+	return func(ctx context.Context, model, text string) ([]float32, error) {
+		body, _ := json.Marshal(map[string]any{"model": model, "input": []string{text}})
+		status, out, _, err := replay(ctx, "/v1/embeddings", model, body)
+		if err != nil {
+			return nil, err
+		}
+		if status != http.StatusOK {
+			msg := strings.TrimSpace(string(out))
+			var e struct {
+				Error struct {
+					Message string `json:"message"`
+				} `json:"error"`
+			}
+			if json.Unmarshal(out, &e) == nil && e.Error.Message != "" {
+				msg = e.Error.Message
+			}
+			return nil, fmt.Errorf("%d: %s", status, msg)
+		}
+		var res struct {
+			Data []struct {
+				Embedding []float32 `json:"embedding"`
+			} `json:"data"`
+		}
+		if err := json.Unmarshal(out, &res); err != nil {
+			return nil, err
+		}
+		if len(res.Data) != 1 || len(res.Data[0].Embedding) == 0 {
+			return nil, fmt.Errorf("%s answered no embedding", model)
+		}
+		return res.Data[0].Embedding, nil
+	}
+}

internal/cli/serverinit_postgres.go

@@ -370,6 +370,8 @@ func (in *serverInit) setupPostgres(ctx context.Context) (string, error) {
 		in.done("PostgreSQL sized for a machine it shares (shared_buffers 96MB, 40 connections)")
 	}
 
+	in.setupPgvector(ctx, discovery.DiscoverHost())
+
 	// Proof the address works, before anything is moved into it.
 	address := "@" + in.dsnPath()
 	s, err := store.Open(ctx, address)
@@ -482,8 +484,17 @@ func lastLines(b []byte, n int) string {
 
 // psql runs one statement as the postgres superuser, over the local socket.
 func (in *serverInit) psql(ctx context.Context, query string) (string, error) {
-	cmd := exec.CommandContext(ctx, "runuser", "-u", "postgres", "--",
-		in.pg.tool("psql"), "-v", "ON_ERROR_STOP=1", "-qAtX", "-c", query)
+	return in.psqlIn(ctx, "", query)
+}
+
+// psqlIn runs a statement as postgres in one database, or in postgres's
+// default one when db is "".
+func (in *serverInit) psqlIn(ctx context.Context, db, query string) (string, error) {
+	args := []string{"-v", "ON_ERROR_STOP=1", "-qAtX", "-c", query}
+	if db != "" {
+		args = append(args, "-d", db)
+	}
+	cmd := exec.CommandContext(ctx, "runuser", append([]string{"-u", "postgres", "--", in.pg.tool("psql")}, args...)...)
 	// postgres cannot enter root's home, and psql says so on every call.
 	cmd.Dir = "/"
 	out, err := cmd.CombinedOutput()
@@ -538,3 +549,50 @@ func (in *serverInit) stopService(ctx context.Context) (bool, error) {
 	in.done("llmgw-server stopped while its store moves")
 	return true, nil
 }
+
+// pgvectorPackages are the package names of pgvector for a PostgreSQL major
+// version: Debian's and Ubuntu's (and PGDG's apt repository) name it after the
+// server, PGDG's rpm repository after the version alone.
+func pgvectorPackages(major int) map[string][]string {
+	return map[string][]string{
+		"deb": {fmt.Sprintf("postgresql-%d-pgvector", major)},
+		"rpm": {fmt.Sprintf("pgvector_%d", major)},
+	}
+}
+
+// setupPgvector installs pgvector and enables it in llmgw's database, for
+// knowledge bases. Not a reason to stop: without it everything else works,
+// and the store says why knowledge bases are off when somebody asks for one.
+func (in *serverInit) setupPgvector(ctx context.Context, h discovery.Host) {
+	warn := func(format string, a ...any) {
+		fmt.Fprintf(in.out, "  !!    pgvector: "+format+"; knowledge bases stay off\n", a...)
+	}
+	if on, err := in.psqlIn(ctx, pgDatabase, "SELECT 1 FROM pg_extension WHERE extname = 'vector'"); err == nil && on == "1" {
+		in.kept("pgvector in database %s", pgDatabase)
+		return
+	}
+	have, err := in.psqlBool(ctx, "SELECT 1 FROM pg_available_extensions WHERE name = 'vector'")
+	if err != nil {
+		warn("%v", err)
+		return
+	}
+	if !have {
+		num, err := in.psql(ctx, "SHOW server_version_num")
+		n, convErr := strconv.Atoi(num)
+		if err != nil || convErr != nil || h.Family() == "" {
+			warn("cannot tell which package to install (version %q, %s)", num, h.OSID)
+			return
+		}
+		pkgs := pgvectorPackages(n / 10000)
+		pi := &provision.Installer{Host: h, Log: slog.Default()}
+		if err := pi.InstallPackages(ctx, pkgs); err != nil {
+			warn("installing %s: %v", strings.Join(pkgs[h.Family()], " "), err)
+			return
+		}
+	}
+	if _, err := in.psqlIn(ctx, pgDatabase, "CREATE EXTENSION IF NOT EXISTS vector"); err != nil {
+		warn("%v", err)
+		return
+	}
+	in.done("pgvector enabled in database %s", pgDatabase)
+}

internal/cli/tui_console.go

@@ -45,6 +45,7 @@ const (
 	cUsage
 	cQuotas
 	cGuard
+	cKB
 	cFederation
 	cMirror
 	cJobs
@@ -68,7 +69,7 @@ const (
 	cCount
 )
 
-var consoleLabels = [cCount]string{"Overview", "Monitor", "Nodes", "GPUs", "Models", "Replicas", "Usage", "Quotas", "Guardrails", "Federation", "Mirror", "Jobs", "Logs", "Accounts", "API keys", "Organizations", "Audit", "Manual",
+var consoleLabels = [cCount]string{"Overview", "Monitor", "Nodes", "GPUs", "Models", "Replicas", "Usage", "Quotas", "Guardrails", "Knowledge", "Federation", "Mirror", "Jobs", "Logs", "Accounts", "API keys", "Organizations", "Audit", "Manual",
 	"server.yaml", "Add a node", "Add a control plane", "Replicate the store", "Serve a model", "Serve the guardrails' judge", "Upgrade the cluster",
 	"Restart all replicas", "Back up now", "Wipe this machine", "Leave"}
 
@@ -177,6 +178,7 @@ type consoleModel struct {
 	quotas    []adminapi.QuotaView
 	quotasErr error
 	guard     guardState
+	kb        kbState
 
 	st     *storeHolder
 	people peopleData
@@ -323,6 +325,9 @@ func (m consoleModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if m.menu == cGuard {
 			cmds = append(cmds, m.fetchGuard())
 		}
+		if m.menu == cKB {
+			cmds = append(cmds, m.fetchKB())
+		}
 		if m.menu == cMirror {
 			cmds = append(cmds, m.fetchMirror())
 		}
@@ -381,6 +386,8 @@ func (m consoleModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.people = peopleData(msg)
 	case consoleQuotasMsg:
 		m.quotas, m.quotasErr = msg.rows, msg.err
+	case consoleKBMsg:
+		m.kb = kbState{view: msg.view, err: msg.err, loaded: true}
 	case consoleGuardMsg:
 		window := m.guard.window
 		m.guard = guardState{view: msg.view, events: msg.events, err: msg.err, window: window}
@@ -539,6 +546,8 @@ func (m consoleModel) key(k tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.menuD = m.quotaMenu(m.quotas[m.row])
 		case cGuard:
 			m.menuD = m.guardAttachmentMenu(m.guard.view.Attachments[m.row])
+		case cKB:
+			m.menuD = m.kbMenu(m.kb.view.Collections[m.row])
 		case cMirror:
 			m.menuD = m.mirrorMenu(m.mirrorGroups()[m.row])
 		case cJobs:
@@ -596,6 +605,10 @@ func (m consoleModel) key(k tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.quotaForm(adminapi.QuotaView{})
 		case cGuard:
 			m.guardAttachForm()
+		case cKB:
+			if m.kb.view.Available {
+				m.kbCreateForm()
+			}
 		case cModels:
 			m.addModelForm()
 		case cMirror:
@@ -651,6 +664,8 @@ func (m consoleModel) onEnter() tea.Cmd {
 		return m.fetchQuotas()
 	case cGuard:
 		return m.fetchGuard()
+	case cKB:
+		return m.fetchKB()
 	case cMirror:
 		return m.fetchMirror()
 	case cMonitor:
@@ -1027,6 +1042,8 @@ func (m consoleModel) rowCount() int {
 		return len(m.quotas)
 	case cGuard:
 		return len(m.guard.view.Attachments)
+	case cKB:
+		return len(m.kb.view.Collections)
 	case cMirror:
 		return len(m.mirrorGroups())
 	case cJobs:
@@ -1260,6 +1277,8 @@ func (m consoleModel) panel() (title, body, keys string) {
 		return m.quotasPanel(pw)
 	case cGuard:
 		return m.guardPanel(pw)
+	case cKB:
+		return m.kbPanel(pw)
 	case cAccounts, cKeys, cOrgs:
 		return m.peoplePanel(pw)
 	case cManual:

internal/cli/tui_kb.go

@@ -0,0 +1,242 @@
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/control/adminapi"
+)
+
+// Knowledge bases, as the console shows them: each collection with its
+// owner, model, documents and grants; Enter for what can be done to one, A
+// to make one. People fill them from their own machines with llmgw-kb.
+
+type kbState struct {
+	view adminapi.KBView
+	err  error
+	// loaded is set once an answer came, so "none yet" is not shown while
+	// asking.
+	loaded bool
+}
+
+type consoleKBMsg struct {
+	view adminapi.KBView
+	err  error
+}
+
+func (m consoleModel) fetchKB() tea.Cmd {
+	c := m.client
+	return func() tea.Msg {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		var msg consoleKBMsg
+		msg.err = c.get(ctx, "/api/v1/kb", &msg.view)
+		return msg
+	}
+}
+
+func (m consoleModel) kbPanel(pw int) (string, string, string) {
+	keys := "→ or Enter open · ↑↓ choose · Q leave"
+	if m.inPanel {
+		keys = "↑↓ collection · Enter actions · A new collection · ← back · Q leave"
+	}
+	k := m.kb
+	var b strings.Builder
+	b.WriteString("\n  " + sDim.Render("Documents requests are answered from; people add them with llmgw-kb.") + "\n\n")
+	switch {
+	case k.err != nil:
+		b.WriteString("  " + sBad.Render(k.err.Error()))
+		return "Knowledge", b.String(), keys
+	case !k.loaded:
+		b.WriteString("  " + sDim.Render("asking the control plane…"))
+		return "Knowledge", b.String(), keys
+	case !k.view.Available:
+		b.WriteString("  " + sBad.Render("Off: ") + k.view.Reason)
+		return "Knowledge", b.String(), keys
+	case len(k.view.Collections) == 0:
+		b.WriteString("  " + sDim.Render("No collections yet. A to make one."))
+		return "Knowledge", b.String(), keys
+	}
+	var rows [][]string
+	for _, c := range k.view.Collections {
+		var grants []string
+		for _, g := range c.Grants {
+			grants = append(grants, or(g.Name, g.Target)+" "+g.Perm)
+		}
+		rows = append(rows, []string{or(c.OrgName, c.Org) + "/" + c.Name, or(c.OwnerName, c.Owner),
+			fmt.Sprintf("%s (%d)", c.EmbedModel, c.Dims), fmt.Sprint(c.Documents), fmt.Sprint(c.Chunks), dash(strings.Join(grants, ", "))})
+	}
+	b.WriteString(table([]string{"COLLECTION", "OWNER", "MODEL", "DOCUMENTS", "CHUNKS", "GRANTED TO"}, rows, m.row, pw, m.inPanel))
+	if len(k.view.Defaults) > 0 {
+		b.WriteString("\n\n  " + sTitle.Render("BY DEFAULT") + "  " + sDim.Render("when a request names no collection") + "\n")
+		var drows [][]string
+		for _, d := range k.view.Defaults {
+			drows = append(drows, []string{or(d.Name, d.Target), strings.Join(d.Collections, ", ")})
+		}
+		b.WriteString(table([]string{"FOR", "ANSWERED FROM"}, drows, -1, pw, false))
+	}
+	b.WriteString("\n\n  " + sDim.Render("On a person's machine: llmgw-kb sync COLLECTION FOLDER"))
+	return "Knowledge", b.String(), keys
+}
+
+// kbRef is how the admin API is told which collection: by its ID.
+func kbRef(c adminapi.KBCollectionView) string { return url.PathEscape(c.ID) }
+
+// kbCreateForm makes a collection.
+func (m *consoleModel) kbCreateForm() {
+	model := ""
+	for _, md := range m.data.models {
+		n := strings.ToLower(md.Name)
+		if strings.Contains(n, "embed") || strings.Contains(n, "bge") || strings.Contains(n, "e5") {
+			model = md.Name
+			break
+		}
+	}
+	m.openForm(&formDialog{title: "New knowledge-base collection",
+		note: "Owned by part of the tree: it and everything below it may read and add to it.\n" +
+			"The model must embed (capabilities.embeddings) and be able to serve now.",
+		fields: []formField{
+			choiceF("owner", []string{"project", "team", "org", "user"}, "team"),
+			textF("which", "", "ORG/TEAM/PROJECT, ORG/TEAM, ORG, or the ID"),
+			textF("org", "", "for a person's collection only"),
+			textF("name", "", "how people name it to llmgw-kb"),
+			textF("model", model, "the catalog model that embeds it"),
+		},
+		submit: func(m *consoleModel, v []string) (tea.Cmd, error) {
+			for i, what := range map[int]string{1: "which " + v[0], 3: "a name", 4: "a model"} {
+				if strings.TrimSpace(v[i]) == "" {
+					return nil, fmt.Errorf("%s?", what)
+				}
+			}
+			req := adminapi.KBCreateRequest{Owner: v[0] + ":" + v[1], Org: v[2], Name: v[3], Model: v[4]}
+			return m.call("New collection "+v[3], http.MethodPost, "/api/v1/kb/collections", req, func(raw json.RawMessage) string {
+				var c adminapi.KBCollectionView
+				_ = json.Unmarshal(raw, &c)
+				return fmt.Sprintf("Collection %s, embedded by %s in %d dimensions.\n\nPeople with access fill it with:\n  llmgw-kb sync %s FOLDER",
+					c.Name, c.EmbedModel, c.Dims, c.Name)
+			}), nil
+		}})
+}
+
+// kbMenu is what can be done to one collection.
+func (m consoleModel) kbMenu(c adminapi.KBCollectionView) *menuDialog {
+	name := or(c.OrgName, c.Org) + "/" + c.Name
+	items := []menuItem{
+		{"Documents", func(m *consoleModel) tea.Cmd { return m.kbDocuments(c) }},
+		{"Grant…", func(m *consoleModel) tea.Cmd {
+			m.openForm(&formDialog{title: "Grant " + name,
+				note: "It and everything below it may then read, or with write add to, this collection.\nNever outside " + or(c.OrgName, c.Org) + ".",
+				fields: []formField{
+					choiceF("to", []string{"project", "team", "org", "user", "key"}, "project"),
+					textF("which", "", "ORG/TEAM/PROJECT, ORG/TEAM, ORG, or the ID"),
+					choiceF("may", []string{"read", "write"}, "read"),
+				},
+				submit: func(m *consoleModel, v []string) (tea.Cmd, error) {
+					if strings.TrimSpace(v[1]) == "" {
+						return nil, fmt.Errorf("which %s?", v[0])
+					}
+					req := adminapi.KBGrantRequest{Collection: c.ID, Target: v[0] + ":" + strings.TrimSpace(v[1]), Perm: v[2]}
+					return m.call("Grant "+c.Name, http.MethodPost, "/api/v1/kb/grants", req, nil), nil
+				}})
+			return nil
+		}},
+	}
+	for _, g := range c.Grants {
+		items = append(items, menuItem{"Revoke " + or(g.Name, g.Target) + " (" + g.Perm + ")…", func(m *consoleModel) tea.Cmd {
+			m.confirmD = &confirmDialog{title: "Revoke a grant on " + name,
+				text: or(g.Name, g.Target) + " may then no longer " + g.Perm + " it, unless it owns it.",
+				yes: func(m *consoleModel) tea.Cmd {
+					return m.call("Revoke", http.MethodDelete, "/api/v1/kb/grants",
+						adminapi.KBGrantRequest{Collection: c.ID, Target: g.Target}, nil)
+				}}
+			return nil
+		}})
+	}
+	items = append(items,
+		menuItem{"Answer from it by default…", func(m *consoleModel) tea.Cmd {
+			m.openForm(&formDialog{title: "Answer from " + name + " by default",
+				note: "Chat requests from there that name no collection are answered from this one.\n" +
+					"Replaces that part's default; llmgw ctl kb default sets several.",
+				fields: []formField{
+					choiceF("for", []string{"project", "team", "org", "key"}, "team"),
+					textF("which", "", "ORG/TEAM/PROJECT, ORG/TEAM, ORG, or the ID"),
+				},
+				submit: func(m *consoleModel, v []string) (tea.Cmd, error) {
+					if strings.TrimSpace(v[1]) == "" {
+						return nil, fmt.Errorf("which %s?", v[0])
+					}
+					req := adminapi.KBDefaultRequest{Target: v[0] + ":" + strings.TrimSpace(v[1]), Collections: []string{c.ID}}
+					return m.call("Default "+c.Name, http.MethodPost, "/api/v1/kb/defaults", req, nil), nil
+				}})
+			return nil
+		}},
+		menuItem{"Try a search…", func(m *consoleModel) tea.Cmd {
+			m.openForm(&formDialog{title: "Search " + name,
+				note:   "As an administrator: no tenancy applies. Shows what a question would find.",
+				fields: []formField{textF("question", "", ""), textF("results", "5", "how many chunks")},
+				submit: func(m *consoleModel, v []string) (tea.Cmd, error) {
+					if v[0] == "" {
+						return nil, fmt.Errorf("what question?")
+					}
+					k, _ := strconv.Atoi(v[1])
+					req := adminapi.KBSearchRequest{Collection: c.ID, Query: v[0], K: k}
+					return m.call("Search "+c.Name, http.MethodPost, "/api/v1/kb/search", req, func(raw json.RawMessage) string {
+						var hits []adminapi.KBHitView
+						_ = json.Unmarshal(raw, &hits)
+						if len(hits) == 0 {
+							return "Nothing found."
+						}
+						var b strings.Builder
+						for i, h := range hits {
+							text := h.Text
+							if r := []rune(text); len(r) > 400 {
+								text = string(r[:400]) + "…"
+							}
+							fmt.Fprintf(&b, "%d. %s #%d\n%s\n\n", i+1, h.Document, h.Ord, indent(strings.TrimSpace(text), "   "))
+						}
+						return strings.TrimRight(b.String(), "\n")
+					}), nil
+				}})
+			return nil
+		}},
+		menuItem{"Delete…", func(m *consoleModel) tea.Cmd {
+			m.confirmD = &confirmDialog{title: "Delete " + name,
+				text: fmt.Sprintf("Its %d documents and %d chunks, and every grant, go with it. People's own files are not touched.",
+					c.Documents, c.Chunks),
+				yes: func(m *consoleModel) tea.Cmd {
+					return m.call("Delete "+c.Name, http.MethodDelete, "/api/v1/kb/collections/"+kbRef(c), nil, nil)
+				}}
+			return nil
+		}},
+	)
+	return &menuDialog{title: name, items: items}
+}
+
+// kbDocuments shows a collection's documents in a dialog.
+func (m *consoleModel) kbDocuments(c adminapi.KBCollectionView) tea.Cmd {
+	return m.call("Documents of "+c.Name, http.MethodGet, "/api/v1/kb/collections/"+kbRef(c)+"/documents", nil,
+		func(raw json.RawMessage) string {
+			var docs []adminapi.KBDocumentView
+			_ = json.Unmarshal(raw, &docs)
+			if len(docs) == 0 {
+				return "None yet. On a person's machine: llmgw-kb sync " + c.Name + " FOLDER"
+			}
+			var b strings.Builder
+			for i, d := range docs {
+				if i == 40 {
+					fmt.Fprintf(&b, "… and %d more (llmgw ctl kb docs %s)", len(docs)-40, c.ID)
+					break
+				}
+				fmt.Fprintf(&b, "%-48s %5d chunks  %s  %s\n", d.Name, d.Chunks, d.AddedAt.Local().Format("2006-01-02 15:04"), d.AddedBy)
+			}
+			return strings.TrimRight(b.String(), "\n")
+		})
+}

internal/cli/tui_kb_test.go

@@ -0,0 +1,62 @@
+package cli
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/control/adminapi"
+)
+
+func TestACollectionIsMadeAndGrantedFromTheConsole(t *testing.T) {
+	m, s := consoleWith(t, cKB)
+	m.data.models = append(m.data.models, adminapi.ModelView{Name: "bge-m3"})
+	m.kb = kbState{loaded: true, view: adminapi.KBView{Available: true, Collections: []adminapi.KBCollectionView{{
+		ID: "kb_aaaaaaaaaaaaaaaa", Name: "policies", Org: "o1", OrgName: "Acme", Owner: "team:t1", OwnerName: "Acme / hr",
+		EmbedModel: "bge-m3", Dims: 1024, Documents: 3, Chunks: 40,
+		Grants: []adminapi.KBGrantView{{Target: "project:p9", Name: "Acme/sales/crm", Perm: "read"}},
+	}}}}
+	var tm tea.Model = m
+	view := tm.View()
+	for _, want := range []string{"Knowledge", "Acme/policies", "Acme / hr", "bge-m3 (1024)", "Acme/s", "llmgw-kb sync COLLECTION FOLDER"} {
+		if !strings.Contains(view, want) {
+			t.Errorf("missing %q in:\n%s", want, view)
+		}
+	}
+
+	// A: the form, prefilled with the embedding model.
+	tm = press(tm, "a")
+	f := tm.(consoleModel).formD
+	if f == nil || f.fields[4].value() != "bge-m3" {
+		t.Fatalf("no form, or the model not offered: %+v", f)
+	}
+	f.fields[1].text.SetValue("Acme/hr")
+	f.fields[3].text.SetValue("handbook")
+	tm = pressRun(tm, "tab", "tab", "tab", "tab", "tab", "enter")
+	var req adminapi.KBCreateRequest
+	got := s.last()
+	if !strings.HasPrefix(got, "POST /api/v1/kb/collections ") ||
+		json.Unmarshal([]byte(strings.SplitN(got, " ", 3)[2]), &req) != nil ||
+		req.Owner != "team:Acme/hr" || req.Name != "handbook" || req.Model != "bge-m3" {
+		t.Fatalf("sent %q", got)
+	}
+
+	// Enter on a row: grant to a project for writing.
+	m.formD = nil
+	tm = m
+	tm = press(tm, "enter")
+	if md := tm.(consoleModel).menuD; md == nil || !strings.Contains(md.items[2].label, "Revoke Acme/sales/crm") {
+		t.Fatalf("menu %+v", md)
+	}
+	tm = press(tm, "down", "enter")
+	f = tm.(consoleModel).formD
+	f.fields[1].text.SetValue("Acme/sales/crm")
+	f.fields[2].opt = 1 // write
+	tm = pressRun(tm, "tab", "tab", "tab", "enter")
+	if got := s.last(); got != `POST /api/v1/kb/grants {"collection":"kb_aaaaaaaaaaaaaaaa","target":"project:Acme/sales/crm","perm":"write"}` {
+		t.Fatalf("sent %q", got)
+	}
+	_ = tm
+}

internal/config/agent.go

@@ -18,7 +18,12 @@ import (
 //
 // An empty path loads the defaults, which with --server and --node-id on the
 // command line is enough for a smoke test on a node with no IB.
-func LoadAgent(path string) (agent.Config, error) {
+func LoadAgent(path string) (agent.Config, error) { return LoadAgentWith(path, nil) }
+
+// LoadAgentWith is LoadAgent with the cluster's settings for this node
+// (agents.default and agents.nodes.<id>, as YAML) laid over the file: the
+// file is what the agent needs to start, the settings what it runs on.
+func LoadAgentWith(path string, settings []byte) (agent.Config, error) {
 	cfg := agent.DefaultConfig()
 	k := koanf.New(".")
 
@@ -30,6 +35,11 @@ func LoadAgent(path string) (agent.Config, error) {
 			return cfg, fmt.Errorf("parsing %s: %w", path, err)
 		}
 	}
+	if len(settings) > 0 {
+		if err := k.Load(bytesProvider(settings), yaml.Parser()); err != nil {
+			return cfg, fmt.Errorf("parsing the cluster's settings for this agent: %w", err)
+		}
+	}
 
 	err := k.Load(env.Provider(".", env.Opt{
 		Prefix: "LLMGW_",

internal/config/agents.go

@@ -0,0 +1,110 @@
+package config
+
+import (
+	"fmt"
+	"slices"
+	"sort"
+)
+
+// AgentSettings are the nodes' agent settings, kept with the cluster's
+// (BACKLOG E3): everything agent.yaml can say except what an agent needs to
+// start — its id, the control planes to dial, its address and its
+// certificate. Default applies to every node, and Nodes, by node id, over
+// it; both over the node's own agent.yaml.
+type AgentSettings struct {
+	// Default is agent.yaml's keys for every node.
+	Default map[string]any `koanf:"default"`
+	// Nodes are agent.yaml's keys for one node each, by node id, over
+	// Default.
+	Nodes map[string]map[string]any `koanf:"nodes"`
+}
+
+// agentBootstrapKeys are what an agent needs before it can be told anything:
+// they stay in agent.yaml.
+var agentBootstrapKeys = []string{"node_id", "server", "servers", "hostname", "mgmt_addr", "tls"}
+
+// For is the settings for one node: Default with the node's own over it.
+// Empty when there are none.
+func (a AgentSettings) For(node string) map[string]any {
+	out := clone(stringKeys(a.Default))
+	if n, ok := a.Nodes[node]; ok {
+		merge(out, stringKeys(n))
+	}
+	return out
+}
+
+// Check refuses settings that set an agent's bootstrap keys, or that would
+// not load as an agent's configuration for some node.
+func (a AgentSettings) Check() error {
+	check := func(where string, m map[string]any) error {
+		for _, k := range agentBootstrapKeys {
+			if _, ok := m[k]; ok {
+				return fmt.Errorf("%s.%s stays in each node's agent.yaml: an agent needs it before it can be told anything", where, k)
+			}
+		}
+		return nil
+	}
+	if err := check("agents.default", stringKeys(a.Default)); err != nil {
+		return err
+	}
+	nodes := make([]string, 0, len(a.Nodes))
+	for n := range a.Nodes {
+		nodes = append(nodes, n)
+	}
+	sort.Strings(nodes)
+	for _, n := range nodes {
+		if err := check("agents.nodes."+n, stringKeys(a.Nodes[n])); err != nil {
+			return err
+		}
+	}
+	// Each node's settings as its agent would load them, over nothing: what
+	// its own file adds cannot be known here, and what is wrong in the
+	// settings alone is wrong on every node.
+	for _, n := range append([]string{""}, nodes...) {
+		b, err := Marshal(a.For(n))
+		if err != nil {
+			return err
+		}
+		if _, err := LoadAgentWith("", b); err != nil {
+			where := "agents.default"
+			if n != "" {
+				where = "agents.nodes." + n
+			}
+			return fmt.Errorf("%s: %w", where, err)
+		}
+	}
+	return nil
+}
+
+// AgentBootstrapKeys are the keys agent.yaml keeps, for saying so.
+func AgentBootstrapKeys() []string { return slices.Clone(agentBootstrapKeys) }
+
+// stringKeys turns YAML's map[any]any, wherever it hides, into the
+// map[string]any the rest of this package merges.
+func stringKeys(m map[string]any) map[string]any {
+	out := make(map[string]any, len(m))
+	for k, v := range m {
+		out[k] = normalize(v)
+	}
+	return out
+}
+
+func normalize(v any) any {
+	switch t := v.(type) {
+	case map[string]any:
+		return stringKeys(t)
+	case map[any]any:
+		m := make(map[string]any, len(t))
+		for k, vv := range t {
+			m[fmt.Sprint(k)] = normalize(vv)
+		}
+		return m
+	case []any:
+		out := make([]any, len(t))
+		for i, vv := range t {
+			out[i] = normalize(vv)
+		}
+		return out
+	}
+	return v
+}

internal/config/agents_test.go

@@ -0,0 +1,79 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestANodesAgentSettingsAreTheDefaultWithItsOwnOver(t *testing.T) {
+	a := AgentSettings{
+		Default: map[string]any{"heartbeat_interval": "5s", "supervisor": map[string]any{"work_dir": "/srv/w", "x": 1}},
+		Nodes: map[string]map[string]any{
+			"cuda01": {"supervisor": map[string]any{"work_dir": "/fast/w"}, "labels": map[string]any{"gpu": "rtx6000"}},
+		},
+	}
+	got := a.For("cuda01")
+	sup := got["supervisor"].(map[string]any)
+	if sup["work_dir"] != "/fast/w" || sup["x"] != 1 || got["heartbeat_interval"] != "5s" || got["labels"] == nil {
+		t.Errorf("cuda01: %v", got)
+	}
+	if got := a.For("node01"); got["labels"] != nil || got["supervisor"].(map[string]any)["work_dir"] != "/srv/w" {
+		t.Errorf("node01: %v", got)
+	}
+	if got := (AgentSettings{}).For("x"); len(got) != 0 {
+		t.Errorf("none: %v", got)
+	}
+}
+
+func TestAgentSettingsKeepBootstrapKeysInTheFileAndMustLoad(t *testing.T) {
+	for _, a := range []AgentSettings{
+		{Default: map[string]any{"servers": []any{"x:7443"}}},
+		{Nodes: map[string]map[string]any{"n1": {"node_id": "other"}}},
+		{Nodes: map[string]map[string]any{"n1": {"tls": map[string]any{"ca": "/x"}}}},
+	} {
+		if err := a.Check(); err == nil || !strings.Contains(err.Error(), "stays in each node's agent.yaml") {
+			t.Errorf("%+v: %v", a, err)
+		}
+	}
+	// A fabric with no adapters would not load on the node it names.
+	bad := AgentSettings{Nodes: map[string]map[string]any{"n1": {"fabrics": []any{map[string]any{"name": "ib-a"}}}}}
+	if err := bad.Check(); err == nil || !strings.Contains(err.Error(), "agents.nodes.n1") || !strings.Contains(err.Error(), "no HCAs") {
+		t.Errorf("a fabric without HCAs: %v", err)
+	}
+	if err := (AgentSettings{Default: map[string]any{"heartbeat_interval": "3s"}}).Check(); err != nil {
+		t.Errorf("a plain setting: %v", err)
+	}
+}
+
+func TestTheClusterSettingsCarryAgentsAndRefuseBadOnes(t *testing.T) {
+	good, err := Parse([]byte("agents:\n  default:\n    heartbeat_interval: 3s\n  nodes:\n    cuda01:\n      labels: {gpu: rtx6000}\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := FromMap(good)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Agents.For("cuda01")["labels"] == nil {
+		t.Errorf("agents not read: %+v", cfg.Agents)
+	}
+	bad, _ := Parse([]byte("agents:\n  default:\n    mgmt_addr: 10.0.0.1\n"))
+	if _, err := FromMap(bad); err == nil {
+		t.Error("a bootstrap key in the cluster's settings was taken")
+	}
+}
+
+func TestTheSettingsAreLaidOverTheAgentsFile(t *testing.T) {
+	p := filepath.Join(t.TempDir(), "agent.yaml")
+	_ = os.WriteFile(p, []byte("node_id: n1\nserver: cp:7443\nheartbeat_interval: 9s\nlabels: {rack: r1}\n"), 0o600)
+	cfg, err := LoadAgentWith(p, []byte("heartbeat_interval: 2s\nlabels: {gpu: a100}\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.NodeID != "n1" || cfg.HeartbeatInterval != 2*time.Second || cfg.Labels["rack"] != "r1" || cfg.Labels["gpu"] != "a100" {
+		t.Errorf("loaded %+v", cfg)
+	}
+}

internal/config/config.go

@@ -158,6 +158,13 @@ type Server struct {
 	// Firewall turns llmgw's firewall on every machine on or off.
 	Firewall FirewallSettings `koanf:"firewall"`
 
+	// Agents are the nodes' agent settings: agent.yaml's keys but those an
+	// agent needs to start, for every node (default) and for one
+	// (nodes.<id>). Sent to the agents as they change; an agent whose
+	// settings changed starts again on them, its engines serving
+	// throughout.
+	Agents AgentSettings `koanf:"agents"`
+
 	// FirewallNetworks are networks, besides those each machine reaches the
 	// cluster on, that llmgw's internal ports answer: a monitoring host on
 	// another subnet, nodes behind a router. Written into every machine's
@@ -887,6 +894,9 @@ func load(b []byte) (Server, error) {
 // Validate rejects configurations that would otherwise fail confusingly at
 // request time.
 func (s Server) Validate() error {
+	if err := s.Agents.Check(); err != nil {
+		return err
+	}
 	for i, o := range s.EngineOverrides {
 		if o.GPUClass == "" && len(o.Nodes) == 0 && len(o.Labels) == 0 {
 			return fmt.Errorf("engine_overrides[%d] picks no nodes: give it a gpu_class, nodes or labels", i)

internal/control/adminapi/api.go

@@ -68,7 +68,9 @@ type API struct {
 	// nil without a store.
 	federation *federation.Service
 	// guard is the guardrail policies' library and attachments.
-	guard    *GuardAdmin
+	guard *GuardAdmin
+	// kb is knowledge bases; nil without a store.
+	kb       *KBAdmin
 	settings *Settings
 	// restartAgents tells every connected agent to start again.
 	restartAgents func(reason string) []string
@@ -114,6 +116,7 @@ func (a *API) Register(mux Mux) {
 	mux.HandleFunc("POST /api/v1/models/{name}/scale", a.scaleModel)
 	mux.HandleFunc("POST /api/v1/models/{name}/resources", a.setResources)
 	a.registerQuotas(mux)
+	a.registerKB(mux)
 	a.registerGuard(mux)
 	a.registerSettings(mux)
 	mux.HandleFunc("POST /api/v1/agents/restart", a.restartAgentsHandler)

internal/control/adminapi/kb.go

@@ -0,0 +1,545 @@
+package adminapi
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+// Knowledge bases, administered (BACKLOG F): collections made, granted,
+// emptied and removed here; documents put into them by people with
+// llmgw-kb, through the gateway.
+
+// KBStore is the part of the store knowledge bases need.
+type KBStore interface {
+	KnowledgeAvailable() error
+	Collections(ctx context.Context) ([]store.KBCollection, error)
+	Collection(ctx context.Context, id string) (store.KBCollection, error)
+	CreateCollection(ctx context.Context, c store.KBCollection) (store.KBCollection, error)
+	DeleteCollection(ctx context.Context, id string) error
+	Grant(ctx context.Context, g store.KBGrant) error
+	Revoke(ctx context.Context, scope store.Scope, scopeID, collection string) (bool, error)
+	Grants(ctx context.Context, collection string) ([]store.KBGrant, error)
+	Documents(ctx context.Context, collection string) ([]store.KBDocument, error)
+	DeleteDocument(ctx context.Context, collection, name string) (bool, error)
+	SearchChunks(ctx context.Context, q store.KBSearch) ([]store.KBHit, error)
+	SetKBDefault(ctx context.Context, d store.KBDefault) error
+	KBDefaults(ctx context.Context) ([]store.KBDefault, error)
+}
+
+// KBAdmin is what the knowledge-base endpoints need: the store, and a way to
+// have a model embed a text (to learn its dimension, and to try a search).
+type KBAdmin struct {
+	Store KBStore
+	Embed func(ctx context.Context, model, text string) ([]float32, error)
+}
+
+// SetKB enables the knowledge-base endpoints.
+func (a *API) SetKB(k *KBAdmin) { a.kb = k }
+
+// KBView is every collection, or why there can be none.
+type KBView struct {
+	Available bool `json:"available"`
+	// Reason is why not, when not.
+	Reason      string             `json:"reason,omitempty"`
+	Collections []KBCollectionView `json:"collections"`
+	// Defaults are the collections parts of the tree answer from when a
+	// request names none.
+	Defaults []KBDefaultView `json:"defaults"`
+}
+
+// KBDefaultView is one part of the tree's default collections.
+type KBDefaultView struct {
+	Target string `json:"target"`
+	Name   string `json:"name,omitempty"`
+	// Collections are ORG/NAME, in order.
+	Collections []string  `json:"collections"`
+	At          time.Time `json:"at"`
+	By          string    `json:"by,omitempty"`
+}
+
+// KBDefaultRequest sets the collections a part of the tree answers from
+// when a request names none; none clears it.
+type KBDefaultRequest struct {
+	// Target is org:, team:, project: (by path or ID) or key:KEY-ID.
+	Target string `json:"target"`
+	// Collections are IDs, names when unique, or ORG/NAME.
+	Collections []string `json:"collections"`
+}
+
+// KBCollectionView is a collection as an administrator sees it.
+type KBCollectionView struct {
+	ID         string `json:"id"`
+	Name       string `json:"name"`
+	Org        string `json:"org"`
+	OrgName    string `json:"org_name,omitempty"`
+	Owner      string `json:"owner"`
+	OwnerName  string `json:"owner_name,omitempty"`
+	EmbedModel string `json:"embed_model"`
+	Dims       int    `json:"dims"`
+	Documents  int    `json:"documents"`
+	Chunks     int    `json:"chunks"`
+	// Grants are who else may read or write it.
+	Grants    []KBGrantView `json:"grants"`
+	CreatedAt time.Time     `json:"created_at"`
+	CreatedBy string        `json:"created_by,omitempty"`
+}
+
+// KBGrantView is one grant.
+type KBGrantView struct {
+	Target string    `json:"target"`
+	Name   string    `json:"name,omitempty"`
+	Perm   string    `json:"perm"`
+	At     time.Time `json:"at"`
+	By     string    `json:"by,omitempty"`
+}
+
+// KBCreateRequest makes a collection.
+type KBCreateRequest struct {
+	// Owner is org:NAME, team:ORG/TEAM, project:ORG/TEAM/PROJECT (or the ID
+	// after the colon), or user:USER-ID.
+	Owner string `json:"owner"`
+	// Org is the organization a person's collection belongs to; only for
+	// user: owners.
+	Org  string `json:"org,omitempty"`
+	Name string `json:"name"`
+	// Model is the catalog model that embeds its documents.
+	Model string `json:"model"`
+	// Dims is the model's embedding dimension; asked of the model when 0.
+	Dims int `json:"dims,omitempty"`
+}
+
+// KBGrantRequest lets a scope read or write a collection, or with DELETE
+// takes that away.
+type KBGrantRequest struct {
+	// Collection is its ID, its name when that is unique, or ORG/NAME.
+	Collection string `json:"collection"`
+	// Target is org:, team:, project:, key: or user: as for guard policies.
+	Target string `json:"target"`
+	// Perm is read or write; ignored by DELETE.
+	Perm string `json:"perm,omitempty"`
+}
+
+// KBDocumentView is one document in a collection.
+type KBDocumentView struct {
+	Name    string    `json:"name"`
+	Digest  string    `json:"digest"`
+	Bytes   int64     `json:"bytes"`
+	Chunks  int       `json:"chunks"`
+	AddedAt time.Time `json:"added_at"`
+	AddedBy string    `json:"added_by,omitempty"`
+}
+
+// KBSearchRequest tries a search, as an administrator: no tenancy applies.
+type KBSearchRequest struct {
+	Collection string `json:"collection"`
+	Query      string `json:"query"`
+	K          int    `json:"k,omitempty"`
+}
+
+// KBHitView is one chunk a search found.
+type KBHitView struct {
+	Document string  `json:"document"`
+	Ord      int     `json:"ord"`
+	Score    float64 `json:"score"`
+	Text     string  `json:"text"`
+}
+
+func (a *API) registerKB(mux Mux) {
+	mux.HandleFunc("GET /api/v1/kb", a.kbList)
+	mux.HandleFunc("POST /api/v1/kb/collections", a.kbCreate)
+	mux.HandleFunc("DELETE /api/v1/kb/collections/{id}", a.kbDelete)
+	mux.HandleFunc("GET /api/v1/kb/collections/{id}/documents", a.kbDocuments)
+	mux.HandleFunc("DELETE /api/v1/kb/collections/{id}/documents", a.kbDeleteDocument)
+	mux.HandleFunc("POST /api/v1/kb/grants", a.kbGrant(true))
+	mux.HandleFunc("DELETE /api/v1/kb/grants", a.kbGrant(false))
+	mux.HandleFunc("POST /api/v1/kb/search", a.kbSearch)
+	mux.HandleFunc("POST /api/v1/kb/defaults", a.kbSetDefault)
+}
+
+// kbReady answers for a gateway without knowledge bases, and says whether
+// it did.
+func (a *API) kbReady(w http.ResponseWriter) bool {
+	if a.kb == nil {
+		writeError(w, http.StatusNotImplemented, "knowledge bases need the store, which this control plane runs without")
+		return false
+	}
+	if err := a.kb.Store.KnowledgeAvailable(); err != nil {
+		writeError(w, http.StatusNotImplemented, err.Error())
+		return false
+	}
+	return true
+}
+
+func (a *API) names(ctx context.Context) map[string]string {
+	if a.quotas == nil {
+		return map[string]string{}
+	}
+	n, err := a.scopeNames(ctx)
+	if err != nil {
+		return map[string]string{}
+	}
+	return n
+}
+
+func (a *API) kbList(w http.ResponseWriter, r *http.Request) {
+	if a.kb == nil {
+		writeJSON(w, http.StatusOK, KBView{Reason: "knowledge bases need the store", Collections: []KBCollectionView{}, Defaults: []KBDefaultView{}})
+		return
+	}
+	if err := a.kb.Store.KnowledgeAvailable(); err != nil {
+		writeJSON(w, http.StatusOK, KBView{Reason: err.Error(), Collections: []KBCollectionView{}, Defaults: []KBDefaultView{}})
+		return
+	}
+	cs, err := a.kb.Store.Collections(r.Context())
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	grants, err := a.kb.Store.Grants(r.Context(), "")
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	names := a.names(r.Context())
+	v := KBView{Available: true, Collections: []KBCollectionView{}, Defaults: []KBDefaultView{}}
+	for _, c := range cs {
+		cv := KBCollectionView{ID: c.ID, Name: c.Name, Org: c.OrgID, OrgName: names["org:"+c.OrgID],
+			Owner: string(c.OwnerScope) + ":" + c.OwnerID, OwnerName: names[string(c.OwnerScope)+":"+c.OwnerID],
+			EmbedModel: c.EmbedModel, Dims: c.Dims, Grants: []KBGrantView{}, CreatedAt: c.CreatedAt, CreatedBy: c.CreatedBy}
+		if docs, err := a.kb.Store.Documents(r.Context(), c.ID); err == nil {
+			cv.Documents = len(docs)
+			for _, d := range docs {
+				cv.Chunks += d.Chunks
+			}
+		}
+		for _, g := range grants {
+			if g.Collection == c.ID {
+				key := string(g.Scope) + ":" + g.ScopeID
+				cv.Grants = append(cv.Grants, KBGrantView{Target: key, Name: names[key], Perm: string(g.Perm), At: g.AddedAt, By: g.AddedBy})
+			}
+		}
+		v.Collections = append(v.Collections, cv)
+	}
+	label := map[string]string{}
+	for _, c := range cs {
+		label[c.ID] = or(names["org:"+c.OrgID], c.OrgID) + "/" + c.Name
+	}
+	defaults, err := a.kb.Store.KBDefaults(r.Context())
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	for _, d := range defaults {
+		key := string(d.Scope) + ":" + d.ScopeID
+		dv := KBDefaultView{Target: key, Name: names[key], Collections: []string{}, At: d.AddedAt, By: d.AddedBy}
+		for _, id := range d.Collections {
+			dv.Collections = append(dv.Collections, or(label[id], id))
+		}
+		v.Defaults = append(v.Defaults, dv)
+	}
+	writeJSON(w, http.StatusOK, v)
+}
+
+// kbTarget reads a grant's or an owner's target: org:, team: and project:
+// by path or ID, key: and user: by ID.
+func (a *API) kbTarget(ctx context.Context, target string) (store.Scope, string, error) {
+	kind, what, ok := strings.Cut(strings.TrimSpace(target), ":")
+	what = strings.TrimSpace(what)
+	if !ok || what == "" {
+		return "", "", fmt.Errorf("%q is not org:, team:, project:, key: or user: and what", target)
+	}
+	switch store.Scope(kind) {
+	case store.ScopeKey, store.ScopeUser:
+		return store.Scope(kind), what, nil
+	case store.ScopeOrg, store.ScopeTeam, store.ScopeProject:
+		if a.quotas == nil {
+			return store.Scope(kind), what, nil
+		}
+		scope, id, _, err := a.resolveScope(ctx, target)
+		return scope, id, err
+	}
+	return "", "", fmt.Errorf("%q: org, team, project, key or user", kind)
+}
+
+// kbFind reads a collection by ID, by its name when that is unique, or by
+// ORG/NAME.
+func (a *API) kbFind(ctx context.Context, ref string) (store.KBCollection, error) {
+	ref = strings.TrimSpace(ref)
+	if c, err := a.kb.Store.Collection(ctx, ref); err == nil {
+		return c, nil
+	}
+	cs, err := a.kb.Store.Collections(ctx)
+	if err != nil {
+		return store.KBCollection{}, err
+	}
+	names := a.names(ctx)
+	org, name, scoped := strings.Cut(ref, "/")
+	var found []store.KBCollection
+	for _, c := range cs {
+		switch {
+		case scoped && strings.EqualFold(c.Name, name) &&
+			(c.OrgID == org || strings.EqualFold(names["org:"+c.OrgID], org)):
+			found = append(found, c)
+		case !scoped && strings.EqualFold(c.Name, ref):
+			found = append(found, c)
+		}
+	}
+	switch len(found) {
+	case 0:
+		return store.KBCollection{}, fmt.Errorf("no collection %q", ref)
+	case 1:
+		return found[0], nil
+	}
+	return store.KBCollection{}, fmt.Errorf("%q names a collection in more than one organization; write ORG/%s", ref, ref)
+}
+
+func (a *API) kbCreate(w http.ResponseWriter, r *http.Request) {
+	if !a.kbReady(w) {
+		return
+	}
+	var in KBCreateRequest
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	scope, id, err := a.kbTarget(r.Context(), in.Owner)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	org := ""
+	if scope == store.ScopeUser {
+		if in.Org == "" {
+			writeError(w, http.StatusBadRequest, "a person's collection names its organization (org)")
+			return
+		}
+		if _, org, err = a.kbTarget(r.Context(), "org:"+in.Org); err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+	}
+	m, ok := a.ctl.Catalog().Resolve(in.Model)
+	if !ok {
+		writeError(w, http.StatusBadRequest, "no model "+in.Model+" in the catalog")
+		return
+	}
+	if !m.Capabilities.Embeddings {
+		writeError(w, http.StatusBadRequest, m.Name+" does not embed (capabilities.embeddings); a collection needs an embedding model")
+		return
+	}
+	dims := in.Dims
+	if dims == 0 {
+		if a.kb.Embed == nil {
+			writeError(w, http.StatusBadRequest, "give the model's dimension (dims): nothing here can ask it")
+			return
+		}
+		// Asked of the model: a dimension typed by hand and wrong would be
+		// found only when the first document is refused.
+		ctx, cancel := context.WithTimeout(r.Context(), 10*time.Minute)
+		defer cancel()
+		v, err := a.kb.Embed(ctx, m.Name, "llmgw")
+		if err != nil {
+			writeError(w, http.StatusBadGateway, "asking "+m.Name+" for its dimension: "+err.Error()+
+				" (is it running? or give dims)")
+			return
+		}
+		dims = len(v)
+	}
+	c, err := a.kb.Store.CreateCollection(r.Context(), store.KBCollection{OwnerScope: scope, OwnerID: id, OrgID: org,
+		Name: in.Name, EmbedModel: m.Name, Dims: dims, CreatedBy: actorOf(r)})
+	if err != nil {
+		code := http.StatusBadRequest
+		if errors.Is(err, store.ErrNotFound) {
+			code = http.StatusNotFound
+		}
+		writeError(w, code, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusCreated, KBCollectionView{ID: c.ID, Name: c.Name, Org: c.OrgID,
+		Owner: string(c.OwnerScope) + ":" + c.OwnerID, EmbedModel: c.EmbedModel, Dims: c.Dims,
+		Grants: []KBGrantView{}, CreatedAt: c.CreatedAt, CreatedBy: c.CreatedBy})
+}
+
+func (a *API) kbCollection(w http.ResponseWriter, r *http.Request) (store.KBCollection, bool) {
+	if !a.kbReady(w) {
+		return store.KBCollection{}, false
+	}
+	c, err := a.kbFind(r.Context(), r.PathValue("id"))
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return store.KBCollection{}, false
+	}
+	return c, true
+}
+
+func (a *API) kbDelete(w http.ResponseWriter, r *http.Request) {
+	c, ok := a.kbCollection(w, r)
+	if !ok {
+		return
+	}
+	if err := a.kb.Store.DeleteCollection(r.Context(), c.ID); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"id": c.ID, "name": c.Name, "deleted": true})
+}
+
+func (a *API) kbDocuments(w http.ResponseWriter, r *http.Request) {
+	c, ok := a.kbCollection(w, r)
+	if !ok {
+		return
+	}
+	docs, err := a.kb.Store.Documents(r.Context(), c.ID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	out := []KBDocumentView{}
+	for _, d := range docs {
+		out = append(out, KBDocumentView{Name: d.Name, Digest: d.Digest, Bytes: d.Bytes, Chunks: d.Chunks,
+			AddedAt: d.AddedAt, AddedBy: d.AddedBy})
+	}
+	writeJSON(w, http.StatusOK, out)
+}
+
+func (a *API) kbDeleteDocument(w http.ResponseWriter, r *http.Request) {
+	c, ok := a.kbCollection(w, r)
+	if !ok {
+		return
+	}
+	name := r.URL.Query().Get("name")
+	gone, err := a.kb.Store.DeleteDocument(r.Context(), c.ID, name)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if !gone {
+		writeError(w, http.StatusNotFound, "no document "+name+" in "+c.Name)
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"name": name, "deleted": true})
+}
+
+func (a *API) kbGrant(grant bool) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !a.kbReady(w) {
+			return
+		}
+		var in KBGrantRequest
+		if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		c, err := a.kbFind(r.Context(), in.Collection)
+		if err != nil {
+			writeError(w, http.StatusNotFound, err.Error())
+			return
+		}
+		scope, id, err := a.kbTarget(r.Context(), in.Target)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		if !grant {
+			gone, err := a.kb.Store.Revoke(r.Context(), scope, id, c.ID)
+			if err != nil {
+				writeError(w, http.StatusInternalServerError, err.Error())
+				return
+			}
+			if !gone {
+				writeError(w, http.StatusNotFound, "no such grant")
+				return
+			}
+			writeJSON(w, http.StatusOK, KBGrantView{Target: string(scope) + ":" + id})
+			return
+		}
+		perm := store.KBPerm(strings.ToLower(strings.TrimSpace(in.Perm)))
+		if perm == "" {
+			perm = store.KBRead
+		}
+		if err := a.kb.Store.Grant(r.Context(), store.KBGrant{Scope: scope, ScopeID: id, Collection: c.ID,
+			Perm: perm, AddedBy: actorOf(r)}); err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		writeJSON(w, http.StatusOK, KBGrantView{Target: string(scope) + ":" + id, Perm: string(perm), At: time.Now(), By: actorOf(r)})
+	}
+}
+
+func (a *API) kbSearch(w http.ResponseWriter, r *http.Request) {
+	if !a.kbReady(w) {
+		return
+	}
+	var in KBSearchRequest
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	c, err := a.kbFind(r.Context(), in.Collection)
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+	k := in.K
+	if k <= 0 || k > 50 {
+		k = 5
+	}
+	q := store.KBSearch{OrgID: c.OrgID, Collections: []store.KBCollection{c}, Text: in.Query, K: k}
+	// Said, not swallowed: a search that quietly lost its meaning half
+	// looks like a collection that does not know the answer.
+	if a.kb.Embed != nil {
+		v, err := a.kb.Embed(r.Context(), c.EmbedModel, in.Query)
+		if err != nil {
+			writeError(w, http.StatusBadGateway, c.EmbedModel+" did not embed the question: "+err.Error())
+			return
+		}
+		q.Embeddings = map[string][]float32{c.EmbedModel: v}
+	}
+	hits, err := a.kb.Store.SearchChunks(r.Context(), q)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	out := []KBHitView{}
+	for _, h := range hits {
+		out = append(out, KBHitView{Document: h.Document, Ord: h.Ord, Score: h.Score, Text: h.Body})
+	}
+	writeJSON(w, http.StatusOK, out)
+}
+
+func (a *API) kbSetDefault(w http.ResponseWriter, r *http.Request) {
+	if !a.kbReady(w) {
+		return
+	}
+	var in KBDefaultRequest
+	if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	scope, id, err := a.kbTarget(r.Context(), in.Target)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	d := store.KBDefault{Scope: scope, ScopeID: id, AddedBy: actorOf(r)}
+	for _, ref := range in.Collections {
+		c, err := a.kbFind(r.Context(), ref)
+		if err != nil {
+			writeError(w, http.StatusNotFound, err.Error())
+			return
+		}
+		d.Collections = append(d.Collections, c.ID)
+	}
+	if err := a.kb.Store.SetKBDefault(r.Context(), d); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, KBDefaultView{Target: string(scope) + ":" + id, Collections: in.Collections, At: time.Now(), By: actorOf(r)})
+}

internal/control/adminapi/kb_test.go

@@ -0,0 +1,138 @@
+package adminapi
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/control/catalog"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+func kbModels() []catalog.Model {
+	return append(testModels(), catalog.Model{Name: "bge-m3", Source: "/e",
+		Capabilities: catalog.Capabilities{Embeddings: true},
+		Profiles:     []catalog.Profile{{Name: "cpu", GPUClass: "h100-80g", TP: 1}}})
+}
+
+func TestKnowledgeBasesListSaysWhyThereAreNone(t *testing.T) {
+	a, _ := setup(t, kbModels())
+	s, err := store.OpenSQLite(context.Background(), filepath.Join(t.TempDir(), "s.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Close()
+	a.SetKB(&KBAdmin{Store: s})
+	var v KBView
+	if code := call(t, a, "GET", "/api/v1/kb", "", &v); code != http.StatusOK || v.Available || !strings.Contains(v.Reason, "SQLite") {
+		t.Errorf("got %d %+v", code, v)
+	}
+	if code := call(t, a, "POST", "/api/v1/kb/collections", `{"owner":"org:x","name":"n","model":"bge-m3"}`, nil); code != http.StatusNotImplemented {
+		t.Errorf("creating on SQLite: %d", code)
+	}
+}
+
+func TestKnowledgeBasesAdministered(t *testing.T) {
+	dsn := os.Getenv("LLMGW_TEST_POSTGRES")
+	if dsn == "" {
+		t.Skip("set LLMGW_TEST_POSTGRES to a pgvector database to run this")
+	}
+	if u, err := url.Parse(dsn); err != nil || !strings.Contains(u.Path, "test") {
+		t.Fatalf("refusing a database whose name does not say test")
+	}
+	ctx := context.Background()
+	s, err := store.OpenPostgres(ctx, dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Close()
+	if err := s.KnowledgeAvailable(); err != nil {
+		t.Skip(err)
+	}
+	a, _ := setup(t, kbModels())
+	a.SetQuotas(s)
+	probes := 0
+	a.SetKB(&KBAdmin{Store: s, Embed: func(_ context.Context, model, _ string) ([]float32, error) {
+		probes++
+		return make([]float32, 4), nil
+	}})
+	sfx := strings.ToLower(store.NewID(""))
+	org, _ := s.CreateOrg(ctx, "Acme"+sfx)
+	team, _ := s.CreateTeam(ctx, org, "hr")
+	_, _ = s.CreateProject(ctx, team, "docs")
+	other, _ := s.CreateOrg(ctx, "Other"+sfx)
+
+	// Owner by path; the dimension asked of the model.
+	var c KBCollectionView
+	rec := func(method, path, body string, out any) int { return call(t, a, method, path, body, out) }
+	body := `{"owner":"team:Acme` + sfx + `/hr","name":"politikalar","model":"bge-m3"}`
+	if code := callCreated(t, a, body, &c); code != http.StatusCreated || c.Dims != 4 || probes != 1 || c.Org != org {
+		t.Fatalf("create: %d %+v (probes %d)", code, c, probes)
+	}
+	// A model that does not embed is refused before anything is written.
+	if code := rec("POST", "/api/v1/kb/collections", `{"owner":"org:`+org+`","name":"x","model":"llama"}`, nil); code != http.StatusBadRequest {
+		t.Errorf("a chat model as the embedder: %d", code)
+	}
+	// Grants by path, never across organizations.
+	if code := rec("POST", "/api/v1/kb/grants", `{"collection":"Acme`+sfx+`/politikalar","target":"project:Acme`+sfx+`/hr/docs","perm":"write"}`, nil); code != http.StatusOK {
+		t.Errorf("grant: %d", code)
+	}
+	if code := rec("POST", "/api/v1/kb/grants", `{"collection":"`+c.ID+`","target":"org:`+other+`"}`, nil); code != http.StatusBadRequest {
+		t.Errorf("a grant to another organization: %d", code)
+	}
+	var v KBView
+	rec("GET", "/api/v1/kb", "", &v)
+	var got *KBCollectionView
+	for i := range v.Collections {
+		if v.Collections[i].ID == c.ID {
+			got = &v.Collections[i]
+		}
+	}
+	if got == nil || len(got.Grants) != 1 || got.Grants[0].Perm != "write" || !strings.Contains(got.OwnerName, "hr") {
+		t.Fatalf("list: %+v", got)
+	}
+	// By ORG/NAME too.
+	if code := rec("DELETE", "/api/v1/kb/grants", `{"collection":"Acme`+sfx+`/politikalar","target":"project:Acme`+sfx+`/hr/docs"}`, nil); code != http.StatusOK {
+		t.Errorf("revoke: %d", code)
+	}
+	if code := rec("DELETE", "/api/v1/kb/collections/"+c.ID, "", nil); code != http.StatusOK {
+		t.Errorf("delete: %d", code)
+	}
+}
+
+func callCreated(t *testing.T, a *API, body string, out any) int {
+	t.Helper()
+	mux := http.NewServeMux()
+	a.Register(mux)
+	r, _ := http.NewRequest("POST", "/api/v1/kb/collections", strings.NewReader(body))
+	r.Header.Set("Content-Type", "application/json")
+	w := &recorder{h: http.Header{}}
+	mux.ServeHTTP(w, r)
+	if w.code == http.StatusCreated {
+		_ = json.Unmarshal(w.body, out)
+	} else {
+		t.Logf("create answered %d %s", w.code, w.body)
+	}
+	return w.code
+}
+
+type recorder struct {
+	h    http.Header
+	code int
+	body []byte
+}
+
+func (r *recorder) Header() http.Header { return r.h }
+func (r *recorder) Write(b []byte) (int, error) {
+	if r.code == 0 {
+		r.code = http.StatusOK
+	}
+	r.body = append(r.body, b...)
+	return len(b), nil
+}
+func (r *recorder) WriteHeader(c int) { r.code = c }

internal/control/adminapi/routes.go

@@ -66,6 +66,7 @@ var PathParams = map[string]string{
 	"quotas/{scope}":    "The scope: org:NAME, team:ORG/TEAM, project:ORG/TEAM/PROJECT, or their IDs after the colon.",
 	"federation/{peer}": "The federation peer's name, as `llmgw ctl federation list` lists it.",
 	"holds/{domain}":    "The domain as level:name, rack:r12-07, as `llmgw ctl facility` lists it.",
+	"collections/{id}":  "The collection's ID, its name when that is unique, or ORG/NAME.",
 }
 
 // Routes is every endpoint Register mounts.
@@ -263,6 +264,34 @@ var Routes = []Route{
 	{Method: "DELETE", Path: "/api/v1/guard/attachments", Summary: "Detach a guardrail policy",
 		Request: GuardAttachmentRequest{}, Response: guard.Attachment{}},
 
+	// Knowledge bases: collections of documents, which people fill with
+	// llmgw-kb from their own machines through the gateway.
+	{Method: "GET", Path: "/api/v1/kb", Summary: "Every knowledge-base collection, with its documents' count and grants",
+		Description: "Says why there are none when the store cannot hold them (SQLite, or PostgreSQL without pgvector).",
+		Response:    KBView{}},
+	{Method: "POST", Path: "/api/v1/kb/collections", Summary: "Make a collection, owned by an organization, team, project or person",
+		Description: "The embedding model's dimension is asked of the model when dims is not given, so the model must be able to serve.",
+		Request:     KBCreateRequest{}, Response: KBCollectionView{}, Status: http.StatusCreated},
+	{Method: "DELETE", Path: "/api/v1/kb/collections/{id}", Summary: "Remove a collection with its documents and grants",
+		Response: map[string]any{}},
+	{Method: "GET", Path: "/api/v1/kb/collections/{id}/documents", Summary: "A collection's documents",
+		Response: []KBDocumentView{}},
+	{Method: "DELETE", Path: "/api/v1/kb/collections/{id}/documents", Summary: "Remove one document from a collection",
+		Query:    []Param{{Name: "name", Description: "The document's name, as listed.", Required: true}},
+		Response: map[string]any{}},
+	{Method: "POST", Path: "/api/v1/kb/grants", Summary: "Let a scope, and everything below it, read or write a collection",
+		Description: "Never outside the collection's organization.",
+		Request:     KBGrantRequest{}, Response: KBGrantView{}},
+	{Method: "DELETE", Path: "/api/v1/kb/grants", Summary: "Take a grant away",
+		Request: KBGrantRequest{}, Response: KBGrantView{}},
+	{Method: "POST", Path: "/api/v1/kb/defaults", Summary: "Set the collections a part of the tree answers from when a request names none",
+		Description: "On an organization, team, project or key; the narrowest one with a default wins. No collections clears it. " +
+			"A request's own X-Llmgw-Knowledge overrides it, and X-Llmgw-Knowledge: none turns it off.",
+		Request: KBDefaultRequest{}, Response: KBDefaultView{}},
+	{Method: "POST", Path: "/api/v1/kb/search", Summary: "Try a search of a collection, as an administrator",
+		Description: "No tenancy applies: this is for checking what a collection holds and finds.",
+		Request:     KBSearchRequest{}, Response: []KBHitView{}},
+
 	{Method: "POST", Path: "/api/v1/agents/restart", Summary: "Have every node's agent start again; their engines keep serving",
 		Response: AgentRestartView{}},
 

internal/control/agentsvc/agentsettings.go

@@ -0,0 +1,50 @@
+package agentsvc
+
+import (
+	"time"
+
+	llmgwv1 "gitea.mynodes.xyz/ilker/llmgw/api/gen/llmgw/v1"
+)
+
+// SetAgentSettings gives the service each node's agent settings from the
+// cluster's (BACKLOG E3), as YAML, read at each use so a change is what is
+// sent next.
+func (s *Service) SetAgentSettings(f func(node string) string) {
+	s.mu.Lock()
+	s.agentSettings = f
+	s.mu.Unlock()
+}
+
+func (s *Service) agentSettingsMsg(node string) *llmgwv1.ControlMessage {
+	s.mu.RLock()
+	f := s.agentSettings
+	s.mu.RUnlock()
+	if f == nil {
+		return nil
+	}
+	return &llmgwv1.ControlMessage{Msg: &llmgwv1.ControlMessage_AgentSettings{
+		AgentSettings: &llmgwv1.AgentSettings{Yaml: f(node)}}}
+}
+
+// agentSettingsGap is the pause between telling one node and the next: an
+// agent whose settings changed starts again, and a whole cluster's agents
+// doing so in the same second would all re-register at once.
+var agentSettingsGap = time.Second
+
+// BroadcastAgentSettings tells every connected agent what the cluster's
+// settings now say it runs on, a moment apart. A node not connected is told
+// when it registers.
+func (s *Service) BroadcastAgentSettings() {
+	for _, node := range s.ConnectedNodes() {
+		msg := s.agentSettingsMsg(node)
+		if msg == nil {
+			return
+		}
+		if err := s.send(node, msg); err != nil {
+			s.log.Warn("could not tell a node its agent settings; it is told when it next registers",
+				"node", node, "err", err)
+			continue
+		}
+		time.Sleep(agentSettingsGap)
+	}
+}

internal/control/agentsvc/agentsettings_test.go

@@ -0,0 +1,28 @@
+package agentsvc
+
+import (
+	"log/slog"
+	"testing"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/control/inventory"
+)
+
+func TestEachNodeIsToldItsOwnAgentSettings(t *testing.T) {
+	s := New(inventory.NewStore(), nil, false, slog.New(slog.DiscardHandler))
+	if s.agentSettingsMsg("n1") != nil {
+		t.Error("told settings with nothing to read them from")
+	}
+	s.SetAgentSettings(func(node string) string {
+		if node == "cuda01" {
+			return "labels:\n  gpu: rtx6000\n"
+		}
+		return ""
+	})
+	if got := s.agentSettingsMsg("cuda01").GetAgentSettings().GetYaml(); got != "labels:\n  gpu: rtx6000\n" {
+		t.Errorf("cuda01 told %q", got)
+	}
+	// None is said too, so an agent whose settings were removed drops them.
+	if m := s.agentSettingsMsg("node01"); m == nil || m.GetAgentSettings().GetYaml() != "" {
+		t.Errorf("node01 told %v", m)
+	}
+}

internal/control/agentsvc/service.go

@@ -79,6 +79,9 @@ type Service struct {
 	controlPlanes func(context.Context) ([]string, error)
 	// firewall is what nodes are told of llmgw's firewall; see SetFirewall.
 	firewall func() *llmgwv1.Firewall
+	// agentSettings is what each node's agent is told to run on; see
+	// SetAgentSettings.
+	agentSettings func(node string) string
 
 	// logWaits are the log requests awaiting a reply, by request id.
 	logMu    sync.Mutex
@@ -296,6 +299,13 @@ func (s *Service) Connect(
 			return err
 		}
 	}
+	// What the cluster's settings say this agent runs on. An agent already
+	// on them ignores it; one that is not starts again on them.
+	if msg := s.agentSettingsMsg(nodeID); msg != nil {
+		if err := stream.Send(msg); err != nil {
+			return err
+		}
+	}
 
 	// Recover replica state from what this node is already running, before any
 	// reconciliation pass can conclude the cluster is empty and place

internal/docgen/reference_gen.go

@@ -19,6 +19,10 @@ var Reference = []Block{
 		{Key: "queue_capacity_total", Type: "int", Doc: "QueueCapacityTotal bounds everything queued across bands. Reached, a\nrequest is not refused while a lower band has any queued: the newest of\nthe lowest band is turned away instead, with a 503 and Retry-After.\nZero takes half of all the bands' capacities together.", Nested: ""},
 		{Key: "interval", Type: "time.Duration", Doc: "", Nested: ""},
 	}},
+	{Package: "config", Name: "AgentSettings", Title: "AgentSettings", Doc: "", Fields: []Field{
+		{Key: "default", Type: "map[string]any", Doc: "Default is agent.yaml's keys for every node.", Nested: ""},
+		{Key: "nodes", Type: "map[string]map[string]any", Doc: "Nodes are agent.yaml's keys for one node each, by node id, over\nDefault.", Nested: ""},
+	}},
 	{Package: "config", Name: "Auth", Title: "Auth", Doc: "", Fields: []Field{
 		{Key: "enabled", Type: "bool", Doc: "", Nested: ""},
 		{Key: "store", Type: "string", Doc: "Store is the SQLite file holding keys, tenancy and usage.", Nested: ""},
@@ -372,6 +376,7 @@ var Reference = []Block{
 		{Key: "mail", Type: "mail.Config", Doc: "Mail is where the gateway's few emails go out from: a link to set a\nforgotten password. Unset, none is sent and people ask an operator.", Nested: "mail.Config"},
 		{Key: "serving", Type: "ServingSettings", Doc: "Serving stops and starts the whole cluster's service (llmgw stop, llmgw\nstart).", Nested: "config.ServingSettings"},
 		{Key: "firewall", Type: "FirewallSettings", Doc: "Firewall turns llmgw's firewall on every machine on or off.", Nested: "config.FirewallSettings"},
+		{Key: "agents", Type: "AgentSettings", Doc: "Agents are the nodes' agent settings: agent.yaml's keys but those an\nagent needs to start, for every node (default) and for one\n(nodes.<id>). Sent to the agents as they change; an agent whose\nsettings changed starts again on them, its engines serving\nthroughout.", Nested: "config.AgentSettings"},
 		{Key: "firewall_networks", Type: "[]string", Doc: "FirewallNetworks are networks, besides those each machine reaches the\ncluster on, that llmgw's internal ports answer: a monitoring host on\nanother subnet, nodes behind a router. Written into every machine's\nfirewall by `server init`, `node add` and `server add`.", Nested: ""},
 		{Key: "backup_recipients", Type: "[]string", Doc: "BackupRecipients encrypt every archive `llmgw server backup` writes, to\nwhoever holds one of their keys: age recipients (age1…) or SSH public\nkeys (ssh-ed25519 …, ssh-rsa …), as `age` takes them. An archive holds\nthe certificate authority's key and every secret in the store, and is\ncopied off the machine; encrypted, the copy is safe wherever it lands.\nEmpty writes archives unencrypted, readable by root only.", Nested: ""},
 		{Key: "backup_copy_to", Type: "[]string", Doc: "BackupCopyTo is where each archive is copied once written, so it\nsurvives this machine: a directory (a mounted share, another disk) or\nssh://user@host[:port]/path, reached with BackupCopyKey and checked\nagainst /etc/llmgw/backup_known_hosts, which learns a host the first\ntime. The same number of archives is kept there as here. Refused\nwithout backup_recipients: an archive leaves the machine encrypted.", Nested: ""},

internal/docgen/render.go

@@ -32,6 +32,7 @@ var Sources = []string{
 	"internal/config/oidc.go",
 	"internal/config/firewall.go",
 	"internal/config/serving.go",
+	"internal/config/agents.go",
 	"internal/mail/mail.go",
 	"internal/notify/notify.go",
 	"internal/secrets/secrets.go",

internal/kb/chunk/chunk.go

@@ -0,0 +1,248 @@
+// Package chunk splits extracted text into the pieces a knowledge base keeps
+// and searches (BACKLOG F2).
+//
+// A chunk is a few paragraphs under the headings they sit beneath: about 500
+// tokens, which an embedding model reads whole and a prompt can carry several
+// of. Paragraphs are not cut while they fit; a section starts a new chunk
+// when the current one is already a fair size, so a chunk rarely mixes two
+// topics; and the last paragraph of a chunk is repeated at the start of the
+// next, so an answer that spans the boundary is found whole in one of them.
+package chunk
+
+import (
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// Options size the chunks. Zero values take the defaults.
+type Options struct {
+	// MaxChars is the most characters in a chunk's body: 1800, about 500
+	// tokens of Turkish or English.
+	MaxChars int
+	// Overlap is the most characters of the previous chunk repeated at the
+	// start of the next: 300.
+	Overlap int
+}
+
+func (o Options) max() int {
+	if o.MaxChars > 0 {
+		return o.MaxChars
+	}
+	return 1800
+}
+
+func (o Options) overlap() int {
+	if o.Overlap >= 0 && o.MaxChars > 0 {
+		return min(o.Overlap, o.max()/2)
+	}
+	return 300
+}
+
+// Chunk is one piece: the headings above it and its text.
+type Chunk struct {
+	// Headings is the path of headings the chunk starts under, widest first.
+	Headings []string
+	Body     string
+}
+
+// Text is what is stored and embedded: the heading path, then the body. The
+// path is part of it so that "how many days?" under "Annual leave" finds the
+// paragraph that says "twenty days" without naming leave.
+func (c Chunk) Text() string {
+	if len(c.Headings) == 0 {
+		return c.Body
+	}
+	return strings.Join(c.Headings, " › ") + "\n\n" + c.Body
+}
+
+// Split cuts Markdown-shaped text into chunks.
+func Split(text string, o Options) []Chunk {
+	max, overlap := o.max(), o.overlap()
+	var out []Chunk
+	type head struct {
+		level int
+		title string
+	}
+	var stack []head // the headings in force, widest first
+	titles := func() []string {
+		out := make([]string, len(stack))
+		for i, h := range stack {
+			out[i] = h.title
+		}
+		return out
+	}
+	var cur []string // blocks of the chunk being built
+	var curHeads []string
+	size := 0
+	// carried is the overlap at the start of cur: it does not count as the
+	// chunk having content of its own.
+	carried := 0
+
+	emit := func(keepOverlap bool) {
+		if size-carried <= 0 {
+			cur, size, carried = nil, 0, 0
+			return
+		}
+		out = append(out, Chunk{Headings: curHeads, Body: strings.Join(cur, "\n\n")})
+		last := cur[len(cur)-1]
+		cur, size, carried = nil, 0, 0
+		if keepOverlap && overlap > 0 && runes(last) <= overlap {
+			cur, size, carried = []string{last}, runes(last), runes(last)
+		}
+	}
+	add := func(b string) {
+		if len(cur) == 0 || size == carried {
+			curHeads = titles()
+		}
+		if size > 0 && size+2+runes(b) > max {
+			emit(true)
+			curHeads = titles()
+		}
+		cur = append(cur, b)
+		size += runes(b) + 2
+	}
+
+	for _, b := range blocks(text) {
+		if lvl, title := heading(b); lvl > 0 {
+			// A new section starts a new chunk once this one is worth
+			// keeping by itself; otherwise the heading goes into it.
+			if size-carried >= max/3 {
+				emit(false)
+			}
+			for len(stack) > 0 && stack[len(stack)-1].level >= lvl {
+				stack = stack[:len(stack)-1]
+			}
+			stack = append(stack, head{lvl, title})
+			if size-carried > 0 {
+				add(b)
+			} else {
+				// Nothing of its own yet: the chunk starts under this heading.
+				cur, size, carried = nil, 0, 0
+				curHeads = titles()
+			}
+			continue
+		}
+		for _, piece := range fit(b, max) {
+			add(piece)
+		}
+	}
+	emit(false)
+	return out
+}
+
+func runes(s string) int { return utf8.RuneCountInString(s) }
+
+// heading reads a Markdown ATX heading line: its level and title.
+func heading(b string) (int, string) {
+	if strings.Contains(b, "\n") {
+		return 0, ""
+	}
+	n := 0
+	for n < len(b) && b[n] == '#' {
+		n++
+	}
+	if n == 0 || n > 6 || n >= len(b) || b[n] != ' ' {
+		return 0, ""
+	}
+	return n, strings.TrimSpace(strings.TrimRight(strings.TrimSpace(b[n:]), "#"))
+}
+
+// blocks splits text on blank lines, keeping fenced code blocks whole.
+func blocks(text string) []string {
+	var out []string
+	var b []string
+	fenced := false
+	flush := func() {
+		s := strings.TrimSpace(strings.Join(b, "\n"))
+		if s != "" {
+			out = append(out, s)
+		}
+		b = nil
+	}
+	for _, line := range strings.Split(text, "\n") {
+		t := strings.TrimSpace(line)
+		if strings.HasPrefix(t, "```") || strings.HasPrefix(t, "~~~") {
+			fenced = !fenced
+		}
+		if !fenced && t == "" {
+			flush()
+			continue
+		}
+		// A heading line is a block of its own even without blank lines
+		// around it.
+		if !fenced && len(b) > 0 {
+			if lvl, _ := heading(t); lvl > 0 {
+				flush()
+			}
+		}
+		b = append(b, strings.TrimRight(line, " \t"))
+		if !fenced {
+			if lvl, _ := heading(t); lvl > 0 {
+				flush()
+			}
+		}
+	}
+	flush()
+	return out
+}
+
+// fit cuts a block longer than max: at line ends, then sentence ends, then
+// spaces, and only as a last resort mid-word.
+func fit(b string, max int) []string {
+	if runes(b) <= max {
+		return []string{b}
+	}
+	for _, split := range []func(string) []string{lines, sentences, words} {
+		parts := split(b)
+		if len(parts) < 2 {
+			continue
+		}
+		var out []string
+		var cur strings.Builder
+		for _, p := range parts {
+			if cur.Len() > 0 && runes(cur.String())+runes(p) > max {
+				out = append(out, strings.TrimSpace(cur.String()))
+				cur.Reset()
+			}
+			if runes(p) > max {
+				out = append(out, fit(strings.TrimSpace(p), max)...)
+				continue
+			}
+			cur.WriteString(p)
+		}
+		if strings.TrimSpace(cur.String()) != "" {
+			out = append(out, strings.TrimSpace(cur.String()))
+		}
+		return out
+	}
+	// One word longer than a chunk: a hash, a line of base64.
+	r := []rune(b)
+	var out []string
+	for len(r) > max {
+		out, r = append(out, string(r[:max])), r[max:]
+	}
+	return append(out, string(r))
+}
+
+// lines splits keeping each line's newline.
+func lines(s string) []string { return strings.SplitAfter(s, "\n") }
+
+// sentences splits after ., ? or ! followed by a space, keeping both.
+func sentences(s string) []string {
+	var out []string
+	start := 0
+	r := []rune(s)
+	for i := 0; i < len(r)-1; i++ {
+		if (r[i] == '.' || r[i] == '?' || r[i] == '!' || r[i] == '…') && unicode.IsSpace(r[i+1]) {
+			out = append(out, string(r[start:i+2]))
+			start = i + 2
+		}
+	}
+	if start < len(r) {
+		out = append(out, string(r[start:]))
+	}
+	return out
+}
+
+func words(s string) []string { return strings.SplitAfter(s, " ") }

internal/kb/chunk/chunk_test.go

@@ -0,0 +1,106 @@
+package chunk
+
+import (
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+func para(word string, n int) string { return strings.TrimSpace(strings.Repeat(word+" ", n)) }
+
+func TestShortTextIsOneChunkUnderItsHeadings(t *testing.T) {
+	cs := Split("# İzin\n\n## Yıllık\n\nYirmi gün.\n\nBayramlar ayrı.\n", Options{})
+	if len(cs) != 1 {
+		t.Fatalf("chunks %+v", cs)
+	}
+	if got := cs[0].Text(); got != "İzin › Yıllık\n\nYirmi gün.\n\nBayramlar ayrı." {
+		t.Errorf("text %q", got)
+	}
+}
+
+func TestChunksStayUnderTheLimitAndOverlap(t *testing.T) {
+	var b strings.Builder
+	for i := range 20 {
+		b.WriteString(para("kelime"+string(rune('a'+i)), 30) + "\n\n")
+	}
+	cs := Split(b.String(), Options{MaxChars: 600, Overlap: 300})
+	if len(cs) < 5 {
+		t.Fatalf("only %d chunks", len(cs))
+	}
+	for i, c := range cs {
+		if n := utf8.RuneCountInString(c.Body); n > 600 {
+			t.Errorf("chunk %d has %d characters", i, n)
+		}
+		if i > 0 {
+			prev := strings.Split(cs[i-1].Body, "\n\n")
+			if !strings.HasPrefix(c.Body, prev[len(prev)-1]) {
+				t.Errorf("chunk %d does not start with the end of chunk %d", i, i-1)
+			}
+		}
+	}
+}
+
+func TestASectionStartsAChunkOnceTheLastIsWorthKeeping(t *testing.T) {
+	text := "# A\n\n" + para("a", 400) + "\n\n# B\n\nkısa\n\n# C\n\nde kısa\n"
+	cs := Split(text, Options{MaxChars: 1800})
+	if len(cs) != 2 {
+		t.Fatalf("chunks %+v", cs)
+	}
+	if cs[1].Headings[0] != "B" || !strings.Contains(cs[1].Body, "# C") || !strings.Contains(cs[1].Body, "de kısa") {
+		t.Errorf("small sections were not kept together: %+v", cs[1])
+	}
+	// The overlap does not run into a new section.
+	if strings.HasPrefix(cs[1].Body, "a a") {
+		t.Errorf("section B starts with section A's text")
+	}
+}
+
+func TestHeadingLevelsReplaceTheirSiblings(t *testing.T) {
+	text := "## A\n\n### A1\n\n" + para("x", 300) + "\n\n## B\n\n" + para("y", 300) + "\n"
+	cs := Split(text, Options{MaxChars: 700})
+	last := cs[len(cs)-1]
+	if strings.Join(last.Headings, "/") != "B" {
+		t.Errorf("headings after a sibling: %v", last.Headings)
+	}
+	if strings.Join(cs[0].Headings, "/") != "A/A1" {
+		t.Errorf("first headings %v", cs[0].Headings)
+	}
+}
+
+func TestLongParagraphsAreCutAtSentencesThenWords(t *testing.T) {
+	long := strings.Repeat("Bu bir cümledir. ", 200)
+	for _, c := range Split(long, Options{MaxChars: 500}) {
+		if utf8.RuneCountInString(c.Body) > 500 {
+			t.Errorf("chunk of %d", utf8.RuneCountInString(c.Body))
+		}
+		if !strings.HasSuffix(c.Body, ".") {
+			t.Errorf("cut mid-sentence: …%q", c.Body[len(c.Body)-20:])
+		}
+	}
+	word := strings.Repeat("ş", 1200)
+	cs := Split(word, Options{MaxChars: 500})
+	total := 0
+	for _, c := range cs {
+		total += utf8.RuneCountInString(c.Body)
+		if !utf8.ValidString(c.Body) {
+			t.Error("a multibyte character was cut")
+		}
+	}
+	if total != 1200 {
+		t.Errorf("a long word lost characters: %d", total)
+	}
+}
+
+func TestCodeFencesStayWhole(t *testing.T) {
+	text := "Örnek:\n\n```go\nfunc a() {\n\n\treturn\n}\n```\n\nSon.\n"
+	cs := Split(text, Options{})
+	if len(cs) != 1 || !strings.Contains(cs[0].Body, "func a() {\n\n\treturn\n}") {
+		t.Errorf("chunks %+v", cs)
+	}
+}
+
+func TestNothingToSayIsNoChunk(t *testing.T) {
+	if cs := Split("# Başlık\n\n## Alt\n", Options{}); len(cs) != 0 {
+		t.Errorf("headings alone made %+v", cs)
+	}
+}

internal/kb/extract/containers.go

@@ -0,0 +1,215 @@
+package extract
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"mime/quotedprintable"
+	"net/mail"
+	"path"
+	"strings"
+)
+
+// maxArchiveMembers is the most members of one archive read; past it the
+// rest are reported skipped.
+const maxArchiveMembers = 10000
+
+// maxArchiveBytes is the most an archive's members are inflated to in all.
+const maxArchiveBytes = 2 << 30
+
+// zipParts reads every member of a zip archive this can read, each a part
+// named by its path inside.
+func zipParts(ctx context.Context, name string, b []byte, o Options, depth int) ([]Part, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return nil, err
+	}
+	var parts []Part
+	var total int64
+	for i, f := range zr.File {
+		if err := ctx.Err(); err != nil {
+			return parts, err
+		}
+		if f.FileInfo().IsDir() || skipName(f.Name) {
+			continue
+		}
+		mname := memberName(f.Name)
+		if i >= maxArchiveMembers {
+			parts = append(parts, Part{Name: mname, Err: fmt.Errorf("%w: past the first %d members", ErrUnsupported, maxArchiveMembers)})
+			continue
+		}
+		if !Known(f.Name) {
+			continue
+		}
+		if int64(f.UncompressedSize64) > o.maxBytes() {
+			parts = append(parts, Part{Name: mname, Err: fmt.Errorf("%w: %d MiB is over the limit", ErrUnsupported, f.UncompressedSize64>>20)})
+			continue
+		}
+		total += int64(f.UncompressedSize64)
+		if total > maxArchiveBytes {
+			parts = append(parts, Part{Name: mname, Err: fmt.Errorf("%w: the archive inflates past %d GiB", ErrUnsupported, maxArchiveBytes>>30)})
+			break
+		}
+		data, err := readMember(f)
+		if err != nil {
+			parts = append(parts, Part{Name: mname, Err: err})
+			continue
+		}
+		inner, err := extractNested(ctx, mname, data, o, depth+1)
+		parts = append(parts, nest(mname, inner, err)...)
+	}
+	if len(parts) == 0 {
+		return nil, ErrNoText
+	}
+	return parts, nil
+}
+
+func extractNested(ctx context.Context, name string, data []byte, o Options, depth int) ([]Part, error) {
+	return extractDepth(ctx, name, data, o, depth)
+}
+
+// nest names the parts of a member after it: "a/b.pdf", "a/c.zip!/d.txt".
+func nest(name string, parts []Part, err error) []Part {
+	if err != nil {
+		return []Part{{Name: name, Err: err}}
+	}
+	out := make([]Part, 0, len(parts))
+	for _, p := range parts {
+		if p.Name == "" {
+			p.Name = name
+		} else {
+			p.Name = name + "!/" + p.Name
+		}
+		out = append(out, p)
+	}
+	return out
+}
+
+// memberName is a member's path made safe to name a document: forward
+// slashes, no leading slash or dot segments.
+func memberName(n string) string {
+	n = strings.ReplaceAll(n, `\`, "/")
+	n = path.Clean("/" + n)
+	return strings.TrimPrefix(n, "/")
+}
+
+// skipName is what systems leave in archives that is not anybody's
+// document: macOS resource forks, Office lock files, thumbnails.
+func skipName(n string) bool {
+	base := path.Base(strings.ReplaceAll(n, `\`, "/"))
+	return strings.HasPrefix(n, "__MACOSX/") || strings.HasPrefix(base, "._") || strings.HasPrefix(base, "~$") ||
+		base == ".DS_Store" || base == "Thumbs.db" || base == "desktop.ini"
+}
+
+// mailParts reads an e-mail (.eml): the message — its headers and the plain
+// text, or the HTML when there is no plain text — and each attachment this
+// can read, named by its file name.
+func mailParts(ctx context.Context, name string, b []byte, o Options, depth int) ([]Part, error) {
+	m, err := mail.ReadMessage(bytes.NewReader(b))
+	if err != nil {
+		return nil, err
+	}
+	dec := new(mime.WordDecoder)
+	dec.CharsetReader = func(cs string, in io.Reader) (io.Reader, error) {
+		all, err := io.ReadAll(in)
+		if err != nil {
+			return nil, err
+		}
+		return strings.NewReader(decodeCharset(all, cs)), nil
+	}
+	header := func(k string) string {
+		v := m.Header.Get(k)
+		if d, err := dec.DecodeHeader(v); err == nil {
+			return d
+		}
+		return v
+	}
+	var plain, htmlBody []string
+	var attachments []Part
+	err = walkMIME(m.Header.Get("Content-Type"), m.Header.Get("Content-Transfer-Encoding"), m.Body, 0,
+		func(ctype, filename string, params map[string]string, body []byte) {
+			if filename != "" {
+				if d, err := dec.DecodeHeader(filename); err == nil {
+					filename = d
+				}
+				if Known(filename) {
+					inner, err := extractNested(ctx, filename, body, o, depth+1)
+					attachments = append(attachments, nest(memberName(filename), inner, err)...)
+				}
+				return
+			}
+			switch ctype {
+			case "text/plain":
+				plain = append(plain, decodeCharset(body, params["charset"]))
+			case "text/html":
+				if t, err := htmlFrom(strings.NewReader(decodeCharset(body, params["charset"]))); err == nil {
+					htmlBody = append(htmlBody, t)
+				}
+			case "message/rfc822":
+				if inner, err := mailParts(ctx, "", body, o, depth+1); err == nil {
+					attachments = append(attachments, nest("message", inner, nil)...)
+				}
+			}
+		})
+	if err != nil && len(plain) == 0 && len(htmlBody) == 0 {
+		return nil, err
+	}
+	var text strings.Builder
+	if s := header("Subject"); s != "" {
+		text.WriteString("# " + s + "\n\n")
+	}
+	for _, k := range []string{"From", "To", "Cc", "Date"} {
+		if v := header(k); v != "" {
+			text.WriteString(k + ": " + v + "\n")
+		}
+	}
+	text.WriteString("\n")
+	body := plain
+	if len(body) == 0 {
+		body = htmlBody
+	}
+	for _, p := range body {
+		text.WriteString(p + "\n\n")
+	}
+	parts := []Part{{Text: Clean(text.String())}}
+	parts = append(parts, attachments...)
+	return parts, nil
+}
+
+// transferDecoder undoes a MIME part's Content-Transfer-Encoding.
+func transferDecoder(cte string, r io.Reader) io.Reader {
+	switch strings.ToLower(strings.TrimSpace(cte)) {
+	case "base64":
+		return base64.NewDecoder(base64.StdEncoding, newlineStripper{r})
+	case "quoted-printable":
+		return quotedprintable.NewReader(r)
+	}
+	return r
+}
+
+// newlineStripper drops CR and LF, which base64 in mail is wrapped with and
+// encoding/base64 does not skip in every position.
+type newlineStripper struct{ r io.Reader }
+
+func (n newlineStripper) Read(p []byte) (int, error) {
+	for {
+		k, err := n.r.Read(p)
+		j := 0
+		for _, c := range p[:k] {
+			if c != '\r' && c != '\n' {
+				p[j] = c
+				j++
+			}
+		}
+		if j > 0 || err != nil {
+			if errors.Is(err, io.EOF) && j > 0 {
+				return j, nil
+			}
+			return j, err
+		}
+	}
+}

internal/kb/extract/extract.go

@@ -0,0 +1,296 @@
+// Package extract turns documents into plain text for knowledge bases
+// (BACKLOG F2), on the machine that holds them.
+//
+// The text it produces is Markdown-shaped: headings as "# ", "## ", list
+// items as "- ", paragraphs separated by a blank line. The chunker splits on
+// exactly those, so a format that knows its headings (DOCX styles, HTML h1–h6,
+// ODT outline levels, slides, sheets) says so, and its chunks carry them.
+//
+// Built-in formats are pure Go, so the client builds for every system without
+// a C toolchain. What Go cannot read — Word 97 files, scanned pages — goes to
+// a helper when one is on the machine (LibreOffice, Tesseract, Poppler), and
+// is otherwise skipped with a sentence saying which helper would read it.
+package extract
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"unicode/utf8"
+)
+
+// ErrUnsupported is a file this cannot read, with the reason wrapped around
+// it ("a .doc needs LibreOffice").
+var ErrUnsupported = errors.New("unsupported")
+
+// ErrNoText is a file that was read and held no text: a scanned PDF without
+// an OCR helper, an empty sheet.
+var ErrNoText = errors.New("no text in it")
+
+// Part is the text of one document. A file is one part; an archive or a mail
+// with attachments is several, each named by its path inside, after the
+// outer file's name and "!/".
+type Part struct {
+	// Name is "" for the file itself, or the path inside it.
+	Name string
+	Text string
+	// Err is why this part was skipped, when it was; Text is then empty.
+	Err error
+}
+
+// Options are the limits and helpers extraction uses.
+type Options struct {
+	Helpers Helpers
+	// MaxBytes is the largest file, or member of an archive, read; 0 is
+	// 256 MiB.
+	MaxBytes int64
+	// OCRLanguages are Tesseract's languages; "" is "tur+eng".
+	OCRLanguages string
+}
+
+func (o Options) maxBytes() int64 {
+	if o.MaxBytes > 0 {
+		return o.MaxBytes
+	}
+	return 256 << 20
+}
+
+// File extracts a file on disk.
+func File(ctx context.Context, name string, o Options) ([]Part, error) {
+	st, err := os.Stat(name)
+	if err != nil {
+		return nil, err
+	}
+	if st.Size() > o.maxBytes() {
+		return nil, fmt.Errorf("%w: %d MiB is over the %d MiB limit", ErrUnsupported, st.Size()>>20, o.maxBytes()>>20)
+	}
+	data, err := os.ReadFile(name)
+	if err != nil {
+		return nil, err
+	}
+	return Bytes(ctx, filepath.Base(name), data, o)
+}
+
+// Bytes extracts a document held in memory; name gives its format.
+func Bytes(ctx context.Context, name string, data []byte, o Options) ([]Part, error) {
+	return extractDepth(ctx, name, data, o, 0)
+}
+
+// maxDepth is how many archives deep members are followed: a zip in a mail
+// in a zip, and no further.
+const maxDepth = 3
+
+func extractDepth(ctx context.Context, name string, data []byte, o Options, depth int) ([]Part, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	ext := Ext(name)
+	if f, ok := containers[ext]; ok {
+		if depth >= maxDepth {
+			return nil, fmt.Errorf("%w: archives nested more than %d deep", ErrUnsupported, maxDepth)
+		}
+		return f(ctx, name, data, o, depth)
+	}
+	text, err := one(ctx, name, ext, data, o)
+	if err != nil {
+		return nil, err
+	}
+	text = Clean(text)
+	if strings.TrimSpace(text) == "" {
+		return nil, ErrNoText
+	}
+	return []Part{{Text: text}}, nil
+}
+
+// one extracts a single document.
+func one(ctx context.Context, name, ext string, data []byte, o Options) (string, error) {
+	if f, ok := builtin[ext]; ok {
+		text, err := f(data)
+		if err == nil && strings.TrimSpace(text) != "" {
+			return text, nil
+		}
+		// A PDF the Go reader cannot parse, or one with no text layer, is
+		// what the helpers are for.
+		if alt, ok := fallback[ext]; ok {
+			if t, aerr := alt(ctx, name, data, o); aerr == nil {
+				return t, nil
+			} else if err == nil {
+				err = aerr
+			}
+		}
+		if err == nil {
+			err = ErrNoText
+		}
+		return "", err
+	}
+	if alt, ok := fallback[ext]; ok {
+		return alt(ctx, name, data, o)
+	}
+	if looksLikeText(data) {
+		return decodeText(data), nil
+	}
+	if o.Helpers.Office != "" {
+		return o.Helpers.officeToText(ctx, name, data, o)
+	}
+	return "", fmt.Errorf("%w: no reader for %q files (LibreOffice, if installed, may read it)", ErrUnsupported, ext)
+}
+
+// Ext is a name's extension, lower case and without the dot.
+func Ext(name string) string {
+	return strings.TrimPrefix(strings.ToLower(path.Ext(strings.ReplaceAll(name, `\`, "/"))), ".")
+}
+
+// Supported lists the extensions read without a helper, and those read with
+// one, for --help and the docs.
+func Supported() (builtIn, withHelper []string) {
+	for e := range builtin {
+		builtIn = append(builtIn, e)
+	}
+	for e := range containers {
+		builtIn = append(builtIn, e)
+	}
+	for e := range textExts {
+		builtIn = append(builtIn, e)
+	}
+	for e := range fallback {
+		if _, ok := builtin[e]; !ok {
+			withHelper = append(withHelper, e)
+		}
+	}
+	sort.Strings(builtIn)
+	sort.Strings(withHelper)
+	return builtIn, withHelper
+}
+
+// Known reports whether a name's extension is one this reads, with or without
+// a helper, or one of the text formats.
+func Known(name string) bool {
+	e := Ext(name)
+	_, a := builtin[e]
+	_, b := containers[e]
+	_, c := fallback[e]
+	return a || b || c || textExts[e]
+}
+
+var (
+	builtin    map[string]func([]byte) (string, error)
+	containers map[string]func(context.Context, string, []byte, Options, int) ([]Part, error)
+	fallback   map[string]func(context.Context, string, []byte, Options) (string, error)
+)
+
+func init() {
+	builtin = map[string]func([]byte) (string, error){
+		"pdf":  pdfText,
+		"html": htmlText, "htm": htmlText, "xhtml": htmlText, "mht": mhtmlText, "mhtml": mhtmlText,
+		"docx": docxText, "docm": docxText, "dotx": docxText, "dotm": docxText,
+		"xlsx": xlsxText, "xlsm": xlsxText, "xltx": xlsxText, "xltm": xlsxText,
+		"pptx": pptxText, "pptm": pptxText, "ppsx": pptxText, "ppsm": pptxText, "potx": pptxText,
+		"odt": odfText, "ott": odfText, "ods": odfText, "ots": odfText, "odp": odfText, "otp": odfText,
+		"fodt": flatODFText, "fods": flatODFText, "fodp": flatODFText,
+		"rtf":   rtfText,
+		"epub":  epubText,
+		"ipynb": notebookText,
+		"srt":   subtitleText, "vtt": subtitleText,
+	}
+	for e := range textExts {
+		builtin[e] = func(b []byte) (string, error) { return decodeText(b), nil }
+	}
+	containers = map[string]func(context.Context, string, []byte, Options, int) ([]Part, error){
+		"zip": zipParts,
+		"eml": mailParts,
+	}
+	fallback = map[string]func(context.Context, string, []byte, Options) (string, error){
+		"pdf": pdfWithHelpers,
+		"rtf": viaOffice,
+	}
+	for _, e := range officeOnly {
+		fallback[e] = viaOffice
+	}
+	for _, e := range imageExts {
+		fallback[e] = viaOCR
+	}
+}
+
+// textExts are formats that are text already: read as they are, decoded.
+var textExts = map[string]bool{
+	"txt": true, "text": true, "md": true, "markdown": true, "mdx": true, "rst": true, "adoc": true,
+	"asciidoc": true, "org": true, "tex": true, "log": true, "csv": true, "tsv": true, "json": true,
+	"jsonl": true, "ndjson": true, "yaml": true, "yml": true, "toml": true, "ini": true, "cfg": true,
+	"conf": true, "properties": true, "env": true, "xml": true, "svg": true, "sql": true,
+	"go": true, "py": true, "js": true, "mjs": true, "cjs": true, "ts": true, "tsx": true, "jsx": true,
+	"java": true, "kt": true, "kts": true, "scala": true, "c": true, "h": true, "cc": true, "cpp": true,
+	"cxx": true, "hpp": true, "hh": true, "cs": true, "fs": true, "vb": true, "rs": true, "swift": true,
+	"m": true, "mm": true, "rb": true, "php": true, "pl": true, "pm": true, "lua": true, "r": true,
+	"jl": true, "dart": true, "ex": true, "exs": true, "erl": true, "hs": true, "clj": true,
+	"sh": true, "bash": true, "zsh": true, "fish": true, "ps1": true, "psm1": true, "bat": true,
+	"cmd": true, "groovy": true, "gradle": true, "tf": true, "hcl": true, "proto": true,
+	"graphql": true, "gql": true, "css": true, "scss": true, "sass": true, "less": true,
+	"vue": true, "svelte": true, "dockerfile": true, "makefile": true, "mk": true, "cmake": true,
+	"bib": true, "nfo": true, "diff": true, "patch": true,
+}
+
+// officeOnly are formats only LibreOffice reads here: the binary Office
+// formats before 2007, and others it opens.
+var officeOnly = []string{
+	"doc", "dot", "xls", "xlt", "xlsb", "ppt", "pps", "pot", "wpd", "wps", "wri",
+	"pages", "numbers", "key", "sxw", "sxc", "sxi", "hwp", "pub", "vsd", "vsdx",
+}
+
+// imageExts are read by OCR.
+var imageExts = []string{"png", "jpg", "jpeg", "tif", "tiff", "bmp", "gif", "webp", "jp2", "pnm"}
+
+// looksLikeText reports whether bytes are text: no NUL in the first 8 KiB
+// (UTF-16 has its BOM checked first), and mostly printable.
+func looksLikeText(b []byte) bool {
+	if hasUTF16BOM(b) {
+		return true
+	}
+	head := b[:min(len(b), 8192)]
+	if bytes.IndexByte(head, 0) >= 0 {
+		return false
+	}
+	if utf8.Valid(head) {
+		return true
+	}
+	// A single-byte code page: allow it when control characters are rare.
+	ctl := 0
+	for _, c := range head {
+		if c < 0x20 && c != '\n' && c != '\r' && c != '\t' && c != '\f' {
+			ctl++
+		}
+	}
+	return ctl*100 < len(head)
+}
+
+var (
+	spaceRun = regexp.MustCompile(`[ \t\x{00A0}]+\n`)
+	blankRun = regexp.MustCompile(`\n{3,}`)
+)
+
+// Clean normalises extracted text: LF line ends, no trailing spaces, no more
+// than one blank line in a row, no control characters but tab and newline.
+func Clean(s string) string {
+	s = strings.ReplaceAll(s, "\r\n", "\n")
+	s = strings.ReplaceAll(s, "\r", "\n")
+	s = strings.Map(func(r rune) rune {
+		switch {
+		case r == '\n' || r == '\t':
+			return r
+		case r == '\f' || r == '\v':
+			return '\n'
+		case r < 0x20 || r == 0x7f || r == utf8.RuneError || r == '\uFEFF':
+			return -1
+		}
+		return r
+	}, s)
+	s = spaceRun.ReplaceAllString(s, "\n")
+	s = blankRun.ReplaceAllString(s, "\n\n")
+	return strings.TrimSpace(s) + "\n"
+}

internal/kb/extract/extract_test.go

@@ -0,0 +1,323 @@
+package extract
+
+import (
+	"archive/zip"
+	"bytes"
+	"context"
+	"encoding/base64"
+	"errors"
+	"os"
+	"strings"
+	"testing"
+
+	"golang.org/x/text/encoding/charmap"
+	"golang.org/x/text/encoding/unicode"
+)
+
+// zipOf builds a zip from name → content, in the order given.
+func zipOf(t *testing.T, files ...string) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	w := zip.NewWriter(&buf)
+	for i := 0; i+1 < len(files); i += 2 {
+		f, err := w.Create(files[i])
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := f.Write([]byte(files[i+1])); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return buf.Bytes()
+}
+
+func extractOne(t *testing.T, name string, data []byte) string {
+	t.Helper()
+	parts, err := Bytes(context.Background(), name, data, Options{})
+	if err != nil {
+		t.Fatalf("%s: %v", name, err)
+	}
+	if len(parts) != 1 || parts[0].Err != nil {
+		t.Fatalf("%s: parts %+v", name, parts)
+	}
+	return parts[0].Text
+}
+
+func wants(t *testing.T, got string, want ...string) {
+	t.Helper()
+	for _, w := range want {
+		if !strings.Contains(got, w) {
+			t.Errorf("missing %q in:\n%s", w, got)
+		}
+	}
+}
+
+func TestTextInEveryEncodingBecomesUTF8(t *testing.T) {
+	const s = "Yıllık izin: Şubat'ta ğüşİöç"
+	u16, _ := unicode.UTF16(unicode.LittleEndian, unicode.UseBOM).NewEncoder().Bytes([]byte(s))
+	cp, _ := charmap.Windows1254.NewEncoder().Bytes([]byte(s))
+	for name, b := range map[string][]byte{
+		"utf8":     []byte(s),
+		"utf8-bom": append([]byte{0xEF, 0xBB, 0xBF}, s...),
+		"utf16":    u16,
+		"cp1254":   cp,
+		"crlf":     []byte(strings.ReplaceAll(s+"\nikinci", "\n", "\r\n")),
+	} {
+		got := extractOne(t, "a.txt", b)
+		if !strings.HasPrefix(got, s) {
+			t.Errorf("%s: got %q", name, got)
+		}
+		if strings.Contains(got, "\r") {
+			t.Errorf("%s: kept a CR", name)
+		}
+	}
+	// macOS writes names and sometimes text decomposed; the text comes out
+	// composed, so the same word is the same bytes everywhere.
+	if got := extractOne(t, "a.txt", []byte("Şirket")); !strings.HasPrefix(got, "Şirket") {
+		t.Errorf("NFD text came out as %q", got)
+	}
+}
+
+func TestHTMLKeepsHeadingsAndDropsScripts(t *testing.T) {
+	page := `<html><head><title>T</title><script>var x="gizli";</script></head><body>
+	<nav>menü</nav><h1>İzin Politikası</h1><p>Yıllık <b>izin</b> yirmi&nbsp;gün.</p>
+	<ul><li>Bir</li><li>İki</li></ul><table><tr><td>a</td><td>b</td></tr></table>
+	<p><b>Mer</b>haba</p></body></html>`
+	got := extractOne(t, "a.html", []byte(page))
+	wants(t, got, "# İzin Politikası", "Yıllık izin yirmi gün.", "- Bir", "- İki", "a\tb", "Merhaba")
+	for _, no := range []string{"gizli", "menü"} {
+		if strings.Contains(got, no) {
+			t.Errorf("%q leaked into:\n%s", no, got)
+		}
+	}
+	// Declared charset honoured.
+	l5, _ := charmap.ISO8859_9.NewEncoder().Bytes([]byte(`<meta charset="iso-8859-9"><p>Şirket</p>`))
+	wants(t, extractOne(t, "b.htm", l5), "Şirket")
+}
+
+func TestWordDocument(t *testing.T) {
+	doc := `<?xml version="1.0" encoding="UTF-8"?>
+<w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main"><w:body>
+<w:p><w:pPr><w:pStyle w:val="Balk1"/></w:pPr><w:r><w:t>Yıllık İzin</w:t></w:r></w:p>
+<w:p><w:r><w:t xml:space="preserve">Çalışanlar </w:t></w:r><w:r><w:t>yirmi gün</w:t></w:r><w:del><w:r><w:delText>otuz</w:delText></w:r></w:del><w:r><w:tab/><w:t>izin alır.</w:t></w:r></w:p>
+<w:p><w:pPr><w:numPr><w:ilvl w:val="0"/></w:numPr></w:pPr><w:r><w:t>Madde bir</w:t></w:r></w:p>
+<w:tbl><w:tr><w:tc><w:p><w:r><w:t>Hücre1</w:t></w:r></w:p></w:tc><w:tc><w:p><w:r><w:t>Hücre2</w:t></w:r></w:p></w:tc></w:tr></w:tbl>
+<w:p><w:pPr><w:pStyle w:val="Heading2"/></w:pPr><w:r><w:t>Masraflar</w:t></w:r></w:p>
+</w:body></w:document>`
+	got := extractOne(t, "a.docx", zipOf(t, "word/document.xml", doc,
+		"word/footnotes.xml", `<w:footnotes xmlns:w="x"><w:footnote><w:p><w:r><w:t>Dipnot</w:t></w:r></w:p></w:footnote></w:footnotes>`))
+	wants(t, got, "# Yıllık İzin", "Çalışanlar yirmi gün\tizin alır.", "- Madde bir", "Hücre1\tHücre2", "## Masraflar", "Dipnot")
+	if strings.Contains(got, "otuz") {
+		t.Errorf("a tracked deletion is in the text:\n%s", got)
+	}
+}
+
+func TestWorkbook(t *testing.T) {
+	got := extractOne(t, "a.xlsx", zipOf(t,
+		"xl/workbook.xml", `<workbook xmlns:r="r"><sheets><sheet name="Bütçe" sheetId="1" r:id="rId1"/><sheet name="Boş" sheetId="2" r:id="rId2"/></sheets></workbook>`,
+		"xl/_rels/workbook.xml.rels", `<Relationships><Relationship Id="rId1" Target="worksheets/sheet1.xml"/><Relationship Id="rId2" Target="worksheets/sheet2.xml"/></Relationships>`,
+		"xl/sharedStrings.xml", `<sst><si><t>Kalem</t></si><si><r><t>Tu</t></r><r><t>tar</t></r></si><si><t>Kira</t></si></sst>`,
+		"xl/worksheets/sheet1.xml", `<worksheet><sheetData><row><c t="s"><v>0</v></c><c t="s"><v>1</v></c></row><row><c t="s"><v>2</v></c><c><v>1500.5</v></c><c t="inlineStr"><is><t>not</t></is></c></row></sheetData></worksheet>`,
+		"xl/worksheets/sheet2.xml", `<worksheet><sheetData/></worksheet>`,
+	))
+	wants(t, got, "## Bütçe", "Kalem\tTutar", "Kira\t1500.5\tnot")
+}
+
+func TestPresentationInItsOwnOrderWithNotes(t *testing.T) {
+	slide := func(text string) string {
+		return `<p:sld xmlns:a="a" xmlns:p="p"><p:cSld><p:spTree><p:sp><p:txBody><a:p><a:r><a:t>` + text +
+			`</a:t></a:r></a:p><a:p><a:fld type="slidenum"><a:t>9</a:t></a:fld></a:p></p:txBody></p:sp></p:spTree></p:cSld></p:sld>`
+	}
+	got := extractOne(t, "a.pptx", zipOf(t,
+		"ppt/presentation.xml", `<p:presentation xmlns:p="p" xmlns:r="r"><p:sldIdLst><p:sldId id="256" r:id="rId3"/><p:sldId id="257" r:id="rId2"/></p:sldIdLst></p:presentation>`,
+		"ppt/_rels/presentation.xml.rels", `<Relationships><Relationship Id="rId2" Target="slides/slide1.xml"/><Relationship Id="rId3" Target="slides/slide2.xml"/></Relationships>`,
+		"ppt/slides/slide1.xml", slide("İkinci slayt"),
+		"ppt/slides/slide2.xml", slide("Birinci slayt"),
+		"ppt/slides/_rels/slide2.xml.rels", `<Relationships><Relationship Id="rId1" Type="http://x/notesSlide" Target="../notesSlides/notesSlide7.xml"/></Relationships>`,
+		"ppt/notesSlides/notesSlide7.xml", slide("Konuşmacı notu"),
+	))
+	first, second := strings.Index(got, "Birinci slayt"), strings.Index(got, "İkinci slayt")
+	if first < 0 || second < 0 || first > second {
+		t.Errorf("slides out of the presentation's order:\n%s", got)
+	}
+	wants(t, got, "## Slide 1", "Notes:", "Konuşmacı notu")
+	if strings.Contains(got, "9") {
+		t.Errorf("a slide number field is in the text:\n%s", got)
+	}
+}
+
+func TestOpenDocument(t *testing.T) {
+	content := `<office:document-content xmlns:office="o" xmlns:text="t" xmlns:table="tb"><office:body><office:text>
+<text:h text:outline-level="2">Bölüm</text:h><text:p>Bir<text:s text:c="2"/>iki<text:tab/>üç</text:p>
+<text:list><text:list-item><text:p>madde</text:p></text:list-item></text:list>
+<table:table table:name="Tablo1"><table:table-row><table:table-cell><text:p>x</text:p></table:table-cell><table:table-cell><text:p>y</text:p></table:table-cell></table:table-row></table:table>
+</office:text></office:body></office:document-content>`
+	got := extractOne(t, "a.odt", zipOf(t, "mimetype", "application/vnd.oasis.opendocument.text", "content.xml", content))
+	wants(t, got, "## Bölüm", "Bir  iki\tüç", "- madde", "## Tablo1", "x\ty")
+	wants(t, extractOne(t, "a.fodt", []byte(content)), "## Bölüm")
+}
+
+func TestRichText(t *testing.T) {
+	rtf := `{\rtf1\ansi\ansicpg1254\deff0{\fonttbl{\f0 Calibri;}}{\colortbl;\red0\green0\blue0;}` +
+		`{\*\generator Riched20;}\pard Y\'fdll\'fdk izin\par ` +
+		`\u350?irket \u-3913?\'3f ok\tab sonra\par{\header gizli}\cell b\row }`
+	got := extractOne(t, "a.rtf", []byte(rtf))
+	wants(t, got, "Yıllık izin", "Şirket", "ok\tsonra")
+	for _, no := range []string{"Calibri", "Riched", "gizli"} {
+		if strings.Contains(got, no) {
+			t.Errorf("%q leaked into:\n%s", no, got)
+		}
+	}
+}
+
+func TestEbookInSpineOrder(t *testing.T) {
+	got := extractOne(t, "a.epub", zipOf(t,
+		"mimetype", "application/epub+zip",
+		"META-INF/container.xml", `<container><rootfiles><rootfile full-path="OEBPS/content.opf"/></rootfiles></container>`,
+		"OEBPS/content.opf", `<package><manifest><item id="c1" href="b.xhtml"/><item id="c2" href="a.xhtml"/></manifest><spine><itemref idref="c2"/><itemref idref="c1"/></spine></package>`,
+		"OEBPS/a.xhtml", `<html><body><h1>Önce</h1></body></html>`,
+		"OEBPS/b.xhtml", `<html><body><h1>Sonra</h1></body></html>`,
+	))
+	if a, b := strings.Index(got, "Önce"), strings.Index(got, "Sonra"); a < 0 || b < a {
+		t.Errorf("chapters out of spine order:\n%s", got)
+	}
+}
+
+func TestNotebookAndSubtitles(t *testing.T) {
+	nb := `{"metadata":{"kernelspec":{"language":"python"}},"cells":[{"cell_type":"markdown","source":["# Analiz\n","Veri"]},
+	{"cell_type":"code","source":"print(1)","outputs":[{"text":"çıktı"}]}]}`
+	got := extractOne(t, "a.ipynb", []byte(nb))
+	wants(t, got, "# Analiz", "```python\nprint(1)\n```")
+	if strings.Contains(got, "çıktı") {
+		t.Errorf("an output is in the text:\n%s", got)
+	}
+	srt := "1\n00:00:01,000 --> 00:00:02,000\n<i>Merhaba</i>\n\n2\n00:00:02,000 --> 00:00:03,000\nMerhaba\nDünya\n"
+	if got := extractOne(t, "a.srt", []byte(srt)); got != "Merhaba\nDünya\n" {
+		t.Errorf("subtitles came out as %q", got)
+	}
+}
+
+func TestPDFTextLayer(t *testing.T) {
+	b, err := os.ReadFile("testdata/turkish.pdf")
+	if err != nil {
+		t.Fatal(err)
+	}
+	wants(t, extractOne(t, "a.pdf", b), "Yıllık İzin Politikası", "Masraflar finans ekibine iletilir.")
+	// Garbage is a failure, not a panic.
+	if _, err := Bytes(context.Background(), "bad.pdf", []byte("%PDF-1.4 nonsense"), Options{}); err == nil {
+		t.Error("a broken PDF was read")
+	}
+}
+
+func TestArchivesAreReadMemberByMember(t *testing.T) {
+	inner := zipOf(t, "deep/c.md", "# Derin")
+	archive := zipOf(t,
+		"docs/a.txt", "Birinci",
+		`docs\b.html`, "<p>İkinci</p>",
+		"__MACOSX/docs/._a.txt", "çöp",
+		"docs/~$kilit.docx", "çöp",
+		"inner.zip", string(inner),
+		"image.bin", "\x00\x01",
+	)
+	parts, err := Bytes(context.Background(), "arsiv.zip", archive, Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := map[string]string{}
+	for _, p := range parts {
+		if p.Err != nil {
+			t.Errorf("%s: %v", p.Name, p.Err)
+		}
+		got[p.Name] = p.Text
+	}
+	if len(got) != 3 || !strings.Contains(got["docs/a.txt"], "Birinci") || !strings.Contains(got["docs/b.html"], "İkinci") ||
+		!strings.Contains(got["inner.zip!/deep/c.md"], "# Derin") {
+		t.Errorf("archive parts %v", got)
+	}
+}
+
+func TestMailWithAttachments(t *testing.T) {
+	att := zipOf(t, "x.txt", "ekteki metin")
+	enc := func(b []byte) string {
+		s := base64.StdEncoding.EncodeToString(b)
+		var lines []string
+		for len(s) > 76 {
+			lines, s = append(lines, s[:76]), s[76:]
+		}
+		return strings.Join(append(lines, s), "\r\n")
+	}
+	msg := "From: =?UTF-8?B?QXnFn2U=?= <a@example.com>\r\n" +
+		"Subject: =?iso-8859-9?Q?=DEubat_raporu?=\r\n" +
+		"Content-Type: multipart/mixed; boundary=B\r\n\r\n" +
+		"--B\r\nContent-Type: multipart/alternative; boundary=C\r\n\r\n" +
+		"--C\r\nContent-Type: text/plain; charset=utf-8\r\nContent-Transfer-Encoding: quoted-printable\r\n\r\n" +
+		"Rapor ekte, te=C5=9Fekk=C3=BCrler.\r\n" +
+		"--C\r\nContent-Type: text/html; charset=utf-8\r\n\r\n<p>HTML hali</p>\r\n--C--\r\n" +
+		"--B\r\nContent-Type: application/zip; name=\"ek.zip\"\r\nContent-Transfer-Encoding: base64\r\n" +
+		"Content-Disposition: attachment; filename=\"ek.zip\"\r\n\r\n" + enc(att) + "\r\n--B--\r\n"
+	parts, err := Bytes(context.Background(), "a.eml", []byte(msg), Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(parts) != 2 {
+		t.Fatalf("parts %+v", parts)
+	}
+	wants(t, parts[0].Text, "# Şubat raporu", "From: Ayşe", "Rapor ekte, teşekkürler.")
+	if strings.Contains(parts[0].Text, "HTML hali") {
+		t.Errorf("the HTML alternative was read beside the plain text:\n%s", parts[0].Text)
+	}
+	if parts[1].Name != "ek.zip!/x.txt" || !strings.Contains(parts[1].Text, "ekteki metin") {
+		t.Errorf("attachment %+v", parts[1])
+	}
+}
+
+func TestUnreadableFilesSayWhy(t *testing.T) {
+	_, err := Bytes(context.Background(), "a.doc", []byte{0xD0, 0xCF, 0x11, 0xE0, 0}, Options{})
+	if !errors.Is(err, ErrUnsupported) || !strings.Contains(err.Error(), "LibreOffice") {
+		t.Errorf("a .doc without LibreOffice gave %v", err)
+	}
+	_, err = Bytes(context.Background(), "a.png", []byte{0x89, 'P', 'N', 'G', 0}, Options{})
+	if !errors.Is(err, ErrUnsupported) || !strings.Contains(err.Error(), "Tesseract") {
+		t.Errorf("an image without Tesseract gave %v", err)
+	}
+	_, err = Bytes(context.Background(), "a.bin", []byte{0, 1, 2, 3}, Options{})
+	if !errors.Is(err, ErrUnsupported) {
+		t.Errorf("binary gave %v", err)
+	}
+	_, err = Bytes(context.Background(), "a.txt", []byte("   \n"), Options{})
+	if !errors.Is(err, ErrNoText) {
+		t.Errorf("an empty file gave %v", err)
+	}
+}
+
+func TestHelpersWhenInstalled(t *testing.T) {
+	h := FindHelpers()
+	ctx := context.Background()
+	if h.Tesseract != "" && h.PdfToPPM != "" {
+		// The text-layer PDF read by OCR instead: what a scanned one gets.
+		b, _ := os.ReadFile("testdata/turkish.pdf")
+		got, err := pdfWithHelpers(ctx, "a.pdf", b, Options{Helpers: Helpers{Tesseract: h.Tesseract, PdfToPPM: h.PdfToPPM}})
+		if err != nil {
+			t.Fatal(err)
+		}
+		wants(t, got, "Masraflar")
+	} else {
+		t.Log("no Tesseract with pdftoppm here; OCR not tried")
+	}
+	if h.Office == "" {
+		t.Log("no LibreOffice here; legacy Office formats not tried")
+		return
+	}
+	// A Word document converted to the legacy format and back would need a
+	// fixture made by Word; an ODT through the Office path proves the
+	// conversion runs and its result is read.
+	content := `<office:document-content xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0" xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0"><office:body><office:text><text:p>LibreOffice yolu</text:p></office:text></office:body></office:document-content>`
+	got, err := h.officeToText(ctx, "a.fodt", []byte(`<?xml version="1.0"?>`+content), Options{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	wants(t, got, "LibreOffice yolu")
+}

internal/kb/extract/helpers.go

@@ -0,0 +1,277 @@
+package extract
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"sort"
+	"strings"
+	"time"
+)
+
+// Helpers are programs on this machine that read what Go here cannot. Any
+// may be "", and the formats that need it are then skipped with a reason.
+type Helpers struct {
+	// Office is LibreOffice's soffice: the binary Office formats and others.
+	Office string
+	// Tesseract reads images and scanned pages.
+	Tesseract string
+	// PdfToText and PdfToPPM are Poppler's: a second PDF reader, and pages
+	// rendered for Tesseract.
+	PdfToText string
+	PdfToPPM  string
+}
+
+// helperTimeout bounds one helper run; a conversion that hangs is a file
+// skipped, not a sync stopped.
+const helperTimeout = 3 * time.Minute
+
+// FindHelpers looks for the helpers on PATH and where their installers put
+// them on each system.
+func FindHelpers() Helpers {
+	return Helpers{
+		Office:    find("soffice", officePlaces()...),
+		Tesseract: find("tesseract", tesseractPlaces()...),
+		PdfToText: find("pdftotext"),
+		PdfToPPM:  find("pdftoppm"),
+	}
+}
+
+// Describe says which helpers were found, and what each missing one would
+// read.
+func (h Helpers) Describe() []string {
+	line := func(have, name, reads string) string {
+		if have != "" {
+			return fmt.Sprintf("%-11s %s", name, have)
+		}
+		return fmt.Sprintf("%-11s not found — %s are skipped", name, reads)
+	}
+	return []string{
+		line(h.Office, "LibreOffice", "Word 97–2003, Excel 97–2003, PowerPoint 97–2003, Pages, Numbers, Keynote and similar files"),
+		line(h.Tesseract, "Tesseract", "images and scanned PDFs"),
+		line(h.PdfToText, "pdftotext", "PDFs the built-in reader cannot parse"),
+		line(h.PdfToPPM, "pdftoppm", "scanned PDFs (Tesseract needs their pages as images)"),
+	}
+}
+
+func find(name string, places ...string) string {
+	exe := name
+	if runtime.GOOS == "windows" {
+		exe += ".exe"
+	}
+	if p, err := exec.LookPath(exe); err == nil {
+		return p
+	}
+	if runtime.GOOS != "windows" {
+		if p, err := exec.LookPath(name); err == nil {
+			return p
+		}
+	}
+	for _, p := range places {
+		if matches, _ := filepath.Glob(p); len(matches) > 0 {
+			sort.Strings(matches)
+			return matches[len(matches)-1]
+		}
+	}
+	return ""
+}
+
+func officePlaces() []string {
+	switch runtime.GOOS {
+	case "windows":
+		return []string{
+			`C:\Program Files\LibreOffice*\program\soffice.exe`,
+			`C:\Program Files (x86)\LibreOffice*\program\soffice.exe`,
+		}
+	case "darwin":
+		return []string{"/Applications/LibreOffice.app/Contents/MacOS/soffice"}
+	}
+	return []string{"/usr/bin/libreoffice", "/usr/lib/libreoffice/program/soffice", "/opt/libreoffice*/program/soffice",
+		"/snap/bin/libreoffice"}
+}
+
+func tesseractPlaces() []string {
+	switch runtime.GOOS {
+	case "windows":
+		return []string{`C:\Program Files\Tesseract-OCR\tesseract.exe`, `C:\Program Files (x86)\Tesseract-OCR\tesseract.exe`}
+	case "darwin":
+		return []string{"/opt/homebrew/bin/tesseract", "/usr/local/bin/tesseract"}
+	}
+	return nil
+}
+
+// workDir is a temporary directory for one helper run, removed after.
+func workDir() (string, func(), error) {
+	d, err := os.MkdirTemp("", "llmgw-kb-")
+	if err != nil {
+		return "", nil, err
+	}
+	return d, func() { _ = os.RemoveAll(d) }, nil
+}
+
+// writeInput puts a document where a helper can read it, under a safe name
+// that keeps its extension.
+func writeInput(dir, name string, data []byte) (string, error) {
+	p := filepath.Join(dir, "input."+Ext(name))
+	return p, os.WriteFile(p, data, 0o600)
+}
+
+func run(ctx context.Context, dir string, bin string, args ...string) ([]byte, error) {
+	ctx, cancel := context.WithTimeout(ctx, helperTimeout)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, bin, args...)
+	cmd.Dir = dir
+	out, err := cmd.Output()
+	if ctx.Err() != nil {
+		return nil, fmt.Errorf("%s took over %s", filepath.Base(bin), helperTimeout)
+	}
+	if err != nil {
+		var ee *exec.ExitError
+		if errors.As(err, &ee) && len(ee.Stderr) > 0 {
+			return nil, fmt.Errorf("%s: %v: %s", filepath.Base(bin), err, lastLine(ee.Stderr))
+		}
+		return nil, fmt.Errorf("%s: %w", filepath.Base(bin), err)
+	}
+	return out, nil
+}
+
+func lastLine(b []byte) string {
+	lines := strings.Split(strings.TrimSpace(string(b)), "\n")
+	return strings.TrimSpace(lines[len(lines)-1])
+}
+
+// fileURL is a path as LibreOffice takes its profile directory: a file URL,
+// with a drive letter on Windows.
+func fileURL(p string) string {
+	p = filepath.ToSlash(p)
+	if !strings.HasPrefix(p, "/") {
+		p = "/" + p
+	}
+	return "file://" + p
+}
+
+var spreadsheets = map[string]bool{"xls": true, "xlt": true, "xlsb": true, "numbers": true, "sxc": true}
+var presentations = map[string]bool{"ppt": true, "pps": true, "pot": true, "key": true, "sxi": true}
+
+func viaOffice(ctx context.Context, name string, data []byte, o Options) (string, error) {
+	if o.Helpers.Office == "" {
+		return "", fmt.Errorf("%w: a .%s file needs LibreOffice, which is not installed here", ErrUnsupported, Ext(name))
+	}
+	return o.Helpers.officeToText(ctx, name, data, o)
+}
+
+// officeToText has LibreOffice convert a document to the matching Office
+// Open XML format, then reads that: headings, sheets and slides survive,
+// which a conversion to plain text would lose.
+func (h Helpers) officeToText(ctx context.Context, name string, data []byte, _ Options) (string, error) {
+	dir, done, err := workDir()
+	if err != nil {
+		return "", err
+	}
+	defer done()
+	in, err := writeInput(dir, name, data)
+	if err != nil {
+		return "", err
+	}
+	ext := Ext(name)
+	to, read := "docx", docxText
+	switch {
+	case spreadsheets[ext]:
+		to, read = "xlsx", xlsxText
+	case presentations[ext]:
+		to, read = "pptx", pptxText
+	}
+	// A profile of its own: two conversions at once with the user's
+	// profile wait on each other's lock, or fail.
+	profile := fileURL(filepath.Join(dir, "profile"))
+	if _, err := run(ctx, dir, h.Office, "-env:UserInstallation="+profile, "--headless", "--norestore",
+		"--convert-to", to, "--outdir", dir, in); err != nil {
+		return "", err
+	}
+	converted, err := os.ReadFile(filepath.Join(dir, "input."+to))
+	if err != nil {
+		return "", fmt.Errorf("LibreOffice did not convert it: %w", err)
+	}
+	return read(converted)
+}
+
+func viaOCR(ctx context.Context, name string, data []byte, o Options) (string, error) {
+	if o.Helpers.Tesseract == "" {
+		return "", fmt.Errorf("%w: an image needs Tesseract to be read, which is not installed here", ErrUnsupported)
+	}
+	dir, done, err := workDir()
+	if err != nil {
+		return "", err
+	}
+	defer done()
+	in, err := writeInput(dir, name, data)
+	if err != nil {
+		return "", err
+	}
+	return ocr(ctx, dir, o, in)
+}
+
+func ocr(ctx context.Context, dir string, o Options, file string) (string, error) {
+	langs := o.OCRLanguages
+	if langs == "" {
+		langs = "tur+eng"
+	}
+	out, err := run(ctx, dir, o.Helpers.Tesseract, file, "stdout", "-l", langs)
+	if err != nil && langs != "eng" {
+		// A Tesseract without the Turkish data still reads English.
+		out, err = run(ctx, dir, o.Helpers.Tesseract, file, "stdout", "-l", "eng")
+	}
+	return string(out), err
+}
+
+// maxOCRPages bounds how many pages of one scanned PDF are read.
+const maxOCRPages = 500
+
+// pdfWithHelpers reads a PDF the built-in reader could not: with pdftotext,
+// and when that finds no text either, page by page through Tesseract.
+func pdfWithHelpers(ctx context.Context, name string, data []byte, o Options) (string, error) {
+	h := o.Helpers
+	if h.PdfToText == "" && (h.Tesseract == "" || h.PdfToPPM == "") {
+		return "", fmt.Errorf("%w: no text layer the built-in reader can use; Poppler (pdftotext) or "+
+			"Tesseract with pdftoppm would read it", ErrNoText)
+	}
+	dir, done, err := workDir()
+	if err != nil {
+		return "", err
+	}
+	defer done()
+	in, err := writeInput(dir, name, data)
+	if err != nil {
+		return "", err
+	}
+	if h.PdfToText != "" {
+		if out, err := run(ctx, dir, h.PdfToText, "-enc", "UTF-8", in, "-"); err == nil && strings.TrimSpace(string(out)) != "" {
+			return string(out), nil
+		}
+	}
+	if h.Tesseract == "" || h.PdfToPPM == "" {
+		return "", fmt.Errorf("%w: a scanned PDF needs Tesseract and pdftoppm", ErrNoText)
+	}
+	if _, err := run(ctx, dir, h.PdfToPPM, "-r", "300", "-gray", "-png", "-l", fmt.Sprint(maxOCRPages), in,
+		filepath.Join(dir, "page")); err != nil {
+		return "", err
+	}
+	pages, _ := filepath.Glob(filepath.Join(dir, "page-*.png"))
+	// pdftoppm pads page numbers to the width of the last one, so the
+	// names sort in page order.
+	sort.Strings(pages)
+	var all strings.Builder
+	for _, p := range pages {
+		t, err := ocr(ctx, dir, o, p)
+		if err != nil {
+			return "", err
+		}
+		all.WriteString(t)
+		all.WriteString("\n\n")
+	}
+	return all.String(), nil
+}

internal/kb/extract/html.go

@@ -0,0 +1,277 @@
+package extract
+
+import (
+	"bytes"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/mail"
+	"strings"
+
+	"golang.org/x/net/html"
+	"golang.org/x/net/html/charset"
+)
+
+// out builds Markdown-shaped text: paragraphs, headings, list items, table
+// rows, with whitespace collapsed inside them.
+type out struct {
+	b strings.Builder
+	// line is the text of the line being built, whitespace collapsed.
+	line   strings.Builder
+	prefix string
+}
+
+// text adds running text; runs of whitespace become one space, and none is
+// added where the source had none ("<b>Mer</b>haba" is one word).
+func (o *out) text(s string) {
+	if s == "" {
+		return
+	}
+	r := []rune(s)
+	lead, trail := isSpace(r[0]), isSpace(r[len(r)-1])
+	for i, f := range strings.FieldsFunc(s, isSpace) {
+		if i > 0 || lead {
+			o.space()
+		}
+		o.line.WriteString(f)
+	}
+	if trail {
+		o.space()
+	}
+}
+
+// space adds one space unless the line is empty or already ends in one.
+func (o *out) space() {
+	l := o.line.String()
+	if l != "" && !strings.HasSuffix(l, " ") && !strings.HasSuffix(l, "\t") {
+		o.line.WriteByte(' ')
+	}
+}
+
+// raw adds text as it is, for preformatted blocks.
+func (o *out) raw(s string) { o.line.WriteString(s) }
+
+// tab separates cells.
+func (o *out) tab() {
+	o.trimLine()
+	o.line.WriteString("\t")
+}
+
+func (o *out) trimLine() {
+	s := strings.TrimRight(o.line.String(), " ")
+	o.line.Reset()
+	o.line.WriteString(s)
+}
+
+// newline ends the line being built, if it has anything.
+func (o *out) newline() {
+	s := strings.TrimSpace(o.line.String())
+	o.line.Reset()
+	if s == "" {
+		return
+	}
+	o.b.WriteString(o.prefix)
+	o.b.WriteString(s)
+	o.b.WriteByte('\n')
+	o.prefix = ""
+}
+
+// para ends a paragraph: the line, and a blank line after it.
+func (o *out) para() {
+	o.newline()
+	if o.b.Len() > 0 && !strings.HasSuffix(o.b.String(), "\n\n") {
+		o.b.WriteByte('\n')
+	}
+}
+
+// heading starts a heading of a level, 1 to 6.
+func (o *out) heading(level int) {
+	o.para()
+	level = max(1, min(level, 6))
+	o.prefix = strings.Repeat("#", level) + " "
+}
+
+// item starts a list item.
+func (o *out) item() {
+	o.newline()
+	o.prefix = "- "
+}
+
+func (o *out) String() string {
+	o.newline()
+	return o.b.String()
+}
+
+func isSpace(r rune) bool {
+	return r == ' ' || r == '\t' || r == '\n' || r == '\r' || r == '\f' || r == ' '
+}
+
+// htmlSkip are elements whose content is not text a reader sees.
+var htmlSkip = map[string]bool{
+	"script": true, "style": true, "noscript": true, "template": true, "svg": true,
+	"head": true, "nav": true, "iframe": true, "object": true, "canvas": true, "button": true, "select": true,
+}
+
+// htmlBlock are elements that end a paragraph.
+var htmlBlock = map[string]bool{
+	"p": true, "div": true, "section": true, "article": true, "main": true, "header": true,
+	"footer": true, "aside": true, "blockquote": true, "pre": true, "table": true, "ul": true,
+	"ol": true, "dl": true, "figure": true, "figcaption": true, "address": true, "hr": true,
+	"form": true, "fieldset": true, "details": true, "summary": true, "body": true, "dt": true, "dd": true,
+	"caption": true,
+}
+
+// htmlText reads an HTML page, in the charset it declares.
+func htmlText(b []byte) (string, error) {
+	r, err := charset.NewReader(bytes.NewReader(b), "text/html")
+	if err != nil {
+		r = bytes.NewReader(b)
+	}
+	return htmlFrom(r)
+}
+
+// htmlFrom reads HTML already decoded to UTF-8.
+func htmlFrom(r io.Reader) (string, error) {
+	z := html.NewTokenizer(r)
+	var o out
+	skip, pre := 0, 0
+	for {
+		tt := z.Next()
+		switch tt {
+		case html.ErrorToken:
+			if z.Err() == io.EOF {
+				return o.String(), nil
+			}
+			return o.String(), z.Err()
+		case html.TextToken:
+			if skip > 0 {
+				continue
+			}
+			if pre > 0 {
+				o.raw(string(z.Text()))
+			} else {
+				o.text(string(z.Text()))
+			}
+		case html.StartTagToken, html.SelfClosingTagToken, html.EndTagToken:
+			name, _ := z.TagName()
+			tag := string(name)
+			end := tt == html.EndTagToken
+			if htmlSkip[tag] {
+				if tt == html.StartTagToken {
+					skip++
+				} else if end && skip > 0 {
+					skip--
+				}
+				continue
+			}
+			if skip > 0 {
+				continue
+			}
+			switch {
+			case len(tag) == 2 && tag[0] == 'h' && tag[1] >= '1' && tag[1] <= '6':
+				if end {
+					o.para()
+				} else {
+					o.heading(int(tag[1] - '0'))
+				}
+			case tag == "title" && !end:
+				// Inside head, which is skipped; a title outside it is a
+				// heading.
+				o.heading(1)
+			case tag == "li":
+				if !end {
+					o.item()
+				} else {
+					o.newline()
+				}
+			case tag == "br":
+				o.newline()
+			case tag == "tr":
+				o.newline()
+			case tag == "td" || tag == "th":
+				if end {
+					o.tab()
+				}
+			case tag == "pre":
+				if end {
+					pre--
+				} else {
+					pre++
+				}
+				o.para()
+			case htmlBlock[tag]:
+				o.para()
+			}
+		}
+	}
+}
+
+// mhtmlText reads a web page saved as one file (MHTML): a MIME message whose
+// HTML part is the page.
+func mhtmlText(b []byte) (string, error) {
+	m, err := mail.ReadMessage(bytes.NewReader(b))
+	if err != nil {
+		return "", err
+	}
+	var best string
+	err = walkMIME(m.Header.Get("Content-Type"), m.Header.Get("Content-Transfer-Encoding"), m.Body, 0,
+		func(ctype, _ string, params map[string]string, body []byte) {
+			if best != "" {
+				return
+			}
+			switch ctype {
+			case "text/html":
+				best, _ = htmlFrom(strings.NewReader(decodeCharset(body, params["charset"])))
+			}
+		})
+	return best, err
+}
+
+// walkMIME calls leaf for every non-multipart part of a MIME body, decoded
+// from its transfer encoding.
+func walkMIME(contentType, cte string, body io.Reader, depth int,
+	leaf func(ctype, filename string, params map[string]string, body []byte),
+) error {
+	if depth > 8 {
+		return nil
+	}
+	ctype, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		ctype, params = "text/plain", map[string]string{}
+	}
+	if strings.HasPrefix(ctype, "multipart/") {
+		mr := multipart.NewReader(body, params["boundary"])
+		for {
+			p, err := mr.NextRawPart()
+			if err == io.EOF {
+				return nil
+			}
+			if err != nil {
+				return err
+			}
+			if err := walkMIME(p.Header.Get("Content-Type"), p.Header.Get("Content-Transfer-Encoding"), p, depth+1,
+				func(ct, fn string, pr map[string]string, b []byte) {
+					if fn == "" {
+						fn = filenameOf(p.Header.Get("Content-Disposition"))
+					}
+					leaf(ct, fn, pr, b)
+				}); err != nil {
+				return err
+			}
+		}
+	}
+	data, err := io.ReadAll(transferDecoder(cte, body))
+	if err != nil {
+		return err
+	}
+	leaf(ctype, params["name"], params, data)
+	return nil
+}
+
+func filenameOf(disposition string) string {
+	_, p, err := mime.ParseMediaType(disposition)
+	if err != nil {
+		return ""
+	}
+	return p["filename"]
+}

internal/kb/extract/misc.go

@@ -0,0 +1,172 @@
+package extract
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"path"
+	"regexp"
+	"strings"
+
+	"github.com/ledongthuc/pdf"
+)
+
+// epubText reads an e-book: its chapters in reading order (the spine).
+func epubText(b []byte) (string, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return "", err
+	}
+	container, _ := member(zr, "META-INF/container.xml")
+	if container == nil {
+		return "", errors.New("not an EPUB: no META-INF/container.xml")
+	}
+	var opf string
+	_ = walkXML(container, func(e xmlEvent) {
+		if e.start && e.name == "rootfile" && opf == "" {
+			opf = e.get("full-path")
+		}
+	})
+	pkg, _ := member(zr, opf)
+	if pkg == nil {
+		return "", fmt.Errorf("not an EPUB: no package document %q", opf)
+	}
+	dir := path.Dir(opf)
+	items := map[string]string{}
+	var spine []string
+	_ = walkXML(pkg, func(e xmlEvent) {
+		switch {
+		case e.start && e.name == "item":
+			items[e.get("id")] = path.Clean(path.Join(dir, e.get("href")))
+		case e.start && e.name == "itemref":
+			spine = append(spine, e.get("idref"))
+		}
+	})
+	var all strings.Builder
+	for _, id := range spine {
+		page, _ := member(zr, items[id])
+		if page == nil {
+			continue
+		}
+		t, err := htmlText(page)
+		if err != nil {
+			continue
+		}
+		all.WriteString(t)
+		all.WriteString("\n\n")
+	}
+	return all.String(), nil
+}
+
+// notebookText reads a Jupyter notebook: Markdown cells as they are, code
+// cells fenced; outputs left out, since they are mostly numbers and images.
+func notebookText(b []byte) (string, error) {
+	var nb struct {
+		Cells []struct {
+			CellType string          `json:"cell_type"`
+			Source   json.RawMessage `json:"source"`
+		} `json:"cells"`
+		Metadata struct {
+			Kernel struct {
+				Language string `json:"language"`
+			} `json:"kernelspec"`
+		} `json:"metadata"`
+	}
+	if err := json.Unmarshal(b, &nb); err != nil {
+		return "", err
+	}
+	var out strings.Builder
+	for _, c := range nb.Cells {
+		src := jsonText(c.Source)
+		if strings.TrimSpace(src) == "" {
+			continue
+		}
+		switch c.CellType {
+		case "code":
+			out.WriteString("```" + nb.Metadata.Kernel.Language + "\n" + strings.TrimRight(src, "\n") + "\n```\n\n")
+		default:
+			out.WriteString(strings.TrimRight(src, "\n") + "\n\n")
+		}
+	}
+	return out.String(), nil
+}
+
+// jsonText is a notebook source: a string, or a list of lines.
+func jsonText(raw json.RawMessage) string {
+	var s string
+	if json.Unmarshal(raw, &s) == nil {
+		return s
+	}
+	var lines []string
+	if json.Unmarshal(raw, &lines) == nil {
+		return strings.Join(lines, "")
+	}
+	return ""
+}
+
+var (
+	subtitleTiming = regexp.MustCompile(`^\d{1,2}:\d{2}(:\d{2})?[.,]\d{3}\s+-->`)
+	subtitleIndex  = regexp.MustCompile(`^\d+$`)
+	subtitleTag    = regexp.MustCompile(`<[^>]+>`)
+)
+
+// subtitleText reads SRT and WebVTT: the spoken lines, without numbers,
+// timings and styling.
+func subtitleText(b []byte) (string, error) {
+	var out strings.Builder
+	last := ""
+	for _, line := range strings.Split(decodeText(b), "\n") {
+		line = strings.TrimSpace(line)
+		switch {
+		case line == "", line == "WEBVTT", strings.HasPrefix(line, "NOTE"),
+			subtitleIndex.MatchString(line), subtitleTiming.MatchString(line):
+			continue
+		}
+		line = strings.TrimSpace(subtitleTag.ReplaceAllString(line, ""))
+		// Captions repeat a line across cues as it scrolls.
+		if line == "" || line == last {
+			continue
+		}
+		last = line
+		out.WriteString(line + "\n")
+	}
+	return out.String(), nil
+}
+
+// pdfText reads a PDF's text layer, page by page, rows in reading order.
+// A scanned PDF has none; pdfWithHelpers is then tried.
+func pdfText(b []byte) (text string, err error) {
+	// The reader panics on some malformed files rather than failing; a bad
+	// PDF is one skipped file, not a stopped sync.
+	defer func() {
+		if r := recover(); r != nil {
+			text, err = "", fmt.Errorf("the PDF could not be parsed: %v", r)
+		}
+	}()
+	r, err := pdf.NewReader(bytes.NewReader(b), int64(len(b)))
+	if err != nil {
+		return "", err
+	}
+	var o out
+	for i := 1; i <= r.NumPage(); i++ {
+		p := r.Page(i)
+		if p.V.IsNull() {
+			continue
+		}
+		rows, err := p.GetTextByRow()
+		if err != nil {
+			continue
+		}
+		for _, row := range rows {
+			var line strings.Builder
+			for _, w := range row.Content {
+				line.WriteString(w.S)
+			}
+			o.text(line.String())
+			o.newline()
+		}
+		o.para()
+	}
+	return o.String(), nil
+}

internal/kb/extract/odf.go

@@ -0,0 +1,117 @@
+package extract
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+)
+
+// odfText reads an OpenDocument file (LibreOffice's ODT, ODS, ODP): its
+// content.xml.
+func odfText(b []byte) (string, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return "", err
+	}
+	content, err := member(zr, "content.xml")
+	if err != nil {
+		return "", err
+	}
+	if content == nil {
+		return "", errors.New("not an OpenDocument file: no content.xml")
+	}
+	return odfXML(content)
+}
+
+// flatODFText reads the single-file XML form (.fodt, .fods, .fodp).
+func flatODFText(b []byte) (string, error) { return odfXML(b) }
+
+// odfXML reads OpenDocument's text model, which all three kinds share:
+// text:h with an outline level is a heading, text:p a paragraph, list items,
+// table rows and cells, slides (draw:page) and sheets (table:table) named as
+// headings.
+func odfXML(b []byte) (string, error) {
+	var o out
+	skip, slide := 0, 0
+	// Paragraphs inside a cell or a list item do not end the row or the list.
+	inCell, inItem := 0, 0
+	err := walkXML(b, func(e xmlEvent) {
+		switch {
+		case e.start:
+			switch e.name {
+			case "tracked-changes", "notes-configuration", "annotation", "frame-name":
+				skip++
+			case "h":
+				lvl, _ := strconv.Atoi(e.get("outline-level"))
+				o.heading(max(lvl, 1))
+			case "list-item":
+				inItem++
+				o.item()
+			case "table-cell":
+				inCell++
+			case "tab":
+				o.raw("\t")
+			case "s":
+				n, _ := strconv.Atoi(e.get("c"))
+				for range max(n, 1) {
+					o.raw(" ")
+				}
+			case "line-break":
+				o.newline()
+			case "page":
+				slide++
+				o.heading(2)
+				name := e.get("name")
+				if name == "" || isDefaultPageName(name) {
+					name = fmt.Sprintf("Slide %d", slide)
+				}
+				o.text(name)
+				o.para()
+			case "table":
+				if n := e.get("name"); n != "" {
+					o.heading(2)
+					o.text(n)
+					o.para()
+				}
+			}
+		case e.end:
+			switch e.name {
+			case "tracked-changes", "notes-configuration", "annotation", "frame-name":
+				skip--
+			case "h", "p":
+				switch {
+				case inCell > 0:
+					o.text(" ")
+				case inItem > 0:
+					o.newline()
+				default:
+					o.para()
+				}
+			case "list-item":
+				inItem--
+				o.newline()
+			case "table-cell":
+				inCell--
+				o.tab()
+			case "table-row":
+				o.newline()
+			case "table", "page":
+				o.para()
+			}
+		default:
+			if skip == 0 {
+				o.raw(e.text)
+			}
+		}
+	})
+	return o.String(), err
+}
+
+// isDefaultPageName is LibreOffice's own name for an unnamed slide, "page1".
+func isDefaultPageName(s string) bool {
+	if len(s) < 5 || s[:4] != "page" {
+		return false
+	}
+	_, err := strconv.Atoi(s[4:])
+	return err == nil
+}

internal/kb/extract/ooxml.go

@@ -0,0 +1,463 @@
+package extract
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"path"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// maxMember is the most one member of an Office file or EPUB is inflated
+// to: a zip bomb stops here rather than at the machine's memory.
+const maxMember = 512 << 20
+
+func openZip(b []byte) (*zip.Reader, error) {
+	return zip.NewReader(bytes.NewReader(b), int64(len(b)))
+}
+
+// member reads one file inside a zip, by its exact name; nil when absent.
+func member(zr *zip.Reader, name string) ([]byte, error) {
+	for _, f := range zr.File {
+		if f.Name == name {
+			return readMember(f)
+		}
+	}
+	return nil, nil
+}
+
+func readMember(f *zip.File) ([]byte, error) {
+	rc, err := f.Open()
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+	b, err := io.ReadAll(io.LimitReader(rc, maxMember+1))
+	if err != nil {
+		return nil, err
+	}
+	if len(b) > maxMember {
+		return nil, fmt.Errorf("%s inflates past %d MiB", f.Name, maxMember>>20)
+	}
+	return b, nil
+}
+
+// relID is an element's r:id, the namespaced id that names a relationship —
+// not its own plain id, which sldId has as well.
+func (e xmlEvent) relID() string {
+	for _, a := range e.attr {
+		if a.Name.Local == "id" && a.Name.Space != "" {
+			return a.Value
+		}
+	}
+	return ""
+}
+
+// xmlEvent is one step of walking an XML document: a start, an end, or
+// character data, with the element's local name and attributes.
+type xmlEvent struct {
+	start, end bool
+	name       string
+	attr       []xml.Attr
+	text       string
+}
+
+func (e xmlEvent) get(local string) string {
+	for _, a := range e.attr {
+		if a.Name.Local == local {
+			return a.Value
+		}
+	}
+	return ""
+}
+
+// walkXML calls f for each element start and end and each run of character
+// data. Namespaces are dropped: OOXML and ODF are read by local names.
+func walkXML(b []byte, f func(xmlEvent)) error {
+	d := xml.NewDecoder(bytes.NewReader(b))
+	d.Strict = false
+	d.CharsetReader = func(cs string, in io.Reader) (io.Reader, error) {
+		all, err := io.ReadAll(in)
+		if err != nil {
+			return nil, err
+		}
+		return strings.NewReader(decodeCharset(all, cs)), nil
+	}
+	for {
+		tok, err := d.Token()
+		if errors.Is(err, io.EOF) {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		switch t := tok.(type) {
+		case xml.StartElement:
+			f(xmlEvent{start: true, name: t.Name.Local, attr: t.Attr})
+		case xml.EndElement:
+			f(xmlEvent{end: true, name: t.Name.Local})
+		case xml.CharData:
+			f(xmlEvent{text: string(t)})
+		}
+	}
+}
+
+// headingLevel reads a heading level out of a paragraph style: Word's
+// "Heading1", "Heading 2", "heading3", its Turkish "Balk1" (the id Word gives
+// "Başlık 1"), "Title" and "Subtitle".
+func headingLevel(style string) int {
+	s := strings.ToLower(strings.ReplaceAll(style, " ", ""))
+	switch s {
+	case "title", "konubaşlığı", "konubal":
+		return 1
+	case "subtitle", "altkonubaşlığı", "altkonubal":
+		return 2
+	}
+	for _, p := range []string{"heading", "balk", "başlık", "berschrift", "titre", "título", "titolo", "kop"} {
+		if rest, ok := strings.CutPrefix(s, p); ok {
+			if n, err := strconv.Atoi(rest); err == nil && n >= 1 && n <= 9 {
+				return min(n, 6)
+			}
+		}
+	}
+	return 0
+}
+
+// docxText reads a Word document: the body, then footnotes and endnotes.
+// Paragraph styles give headings; tables are rows of tab-separated cells.
+func docxText(b []byte) (string, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return "", err
+	}
+	body, err := member(zr, "word/document.xml")
+	if err != nil {
+		return "", err
+	}
+	if body == nil {
+		return "", errors.New("not a Word document: no word/document.xml")
+	}
+	var o out
+	if err := wordML(body, &o); err != nil {
+		return "", err
+	}
+	for _, extra := range []string{"word/footnotes.xml", "word/endnotes.xml"} {
+		if x, _ := member(zr, extra); x != nil {
+			_ = wordML(x, &o)
+		}
+	}
+	return o.String(), nil
+}
+
+func wordML(b []byte, o *out) error {
+	inText, inDel, inCell := false, 0, 0
+	level, list := 0, false
+	return walkXML(b, func(e xmlEvent) {
+		switch {
+		case e.start:
+			switch e.name {
+			case "p":
+				level, list = 0, false
+			case "pStyle":
+				level = headingLevel(e.get("val"))
+				if strings.Contains(strings.ToLower(e.get("val")), "list") {
+					list = true
+				}
+			case "numPr":
+				list = true
+			case "t":
+				inText = true
+				if level > 0 && inCell == 0 && o.line.Len() == 0 && o.prefix == "" {
+					o.heading(level)
+				} else if list && inCell == 0 && o.line.Len() == 0 && o.prefix == "" {
+					o.item()
+				}
+			case "delText":
+				// Tracked deletions are not the document's text.
+				inDel++
+			case "tc":
+				inCell++
+			case "tab":
+				o.raw("\t")
+			case "br", "cr":
+				o.newline()
+			}
+		case e.end:
+			switch e.name {
+			case "t":
+				inText = false
+			case "delText":
+				inDel--
+			case "p":
+				switch {
+				case inCell > 0:
+					// A cell's paragraphs stay in its row.
+					o.text(" ")
+				case list:
+					o.newline()
+				default:
+					o.para()
+				}
+			case "tc":
+				inCell--
+				o.tab()
+			case "tr":
+				o.newline()
+			case "tbl":
+				o.para()
+			}
+		default:
+			if inText && inDel == 0 {
+				o.raw(e.text)
+			}
+		}
+	})
+}
+
+// xlsxText reads a workbook: each sheet under its name as a heading, each
+// row a line of tab-separated cells, shared strings resolved.
+func xlsxText(b []byte) (string, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return "", err
+	}
+	var shared []string
+	if ss, _ := member(zr, "xl/sharedStrings.xml"); ss != nil {
+		var cur strings.Builder
+		inT, inRPh := false, 0
+		_ = walkXML(ss, func(e xmlEvent) {
+			switch {
+			case e.start && e.name == "si":
+				cur.Reset()
+			case e.end && e.name == "si":
+				shared = append(shared, cur.String())
+			case e.start && e.name == "rPh":
+				inRPh++ // phonetic guides, not the cell's text
+			case e.end && e.name == "rPh":
+				inRPh--
+			case e.start && e.name == "t":
+				inT = true
+			case e.end && e.name == "t":
+				inT = false
+			case !e.start && !e.end && inT && inRPh == 0:
+				cur.WriteString(e.text)
+			}
+		})
+	}
+	sheets, err := xlsxSheets(zr)
+	if err != nil {
+		return "", err
+	}
+	var o out
+	for _, sh := range sheets {
+		data, err := member(zr, sh.path)
+		if err != nil || data == nil {
+			continue
+		}
+		o.heading(2)
+		o.text(sh.name)
+		o.para()
+		var cell strings.Builder
+		cellType, inV, inIs := "", false, false
+		first := true
+		_ = walkXML(data, func(e xmlEvent) {
+			switch {
+			case e.start && e.name == "row":
+				first = true
+			case e.end && e.name == "row":
+				o.newline()
+			case e.start && e.name == "c":
+				cellType = e.get("t")
+				cell.Reset()
+			case e.end && e.name == "c":
+				v := cell.String()
+				if cellType == "s" {
+					if i, err := strconv.Atoi(strings.TrimSpace(v)); err == nil && i >= 0 && i < len(shared) {
+						v = shared[i]
+					}
+				}
+				v = strings.TrimSpace(strings.ReplaceAll(v, "\n", " "))
+				if v != "" {
+					if !first {
+						o.tab()
+					}
+					o.text(v)
+					first = false
+				}
+			case e.start && e.name == "v":
+				inV = true
+			case e.end && e.name == "v":
+				inV = false
+			case e.start && e.name == "is":
+				inIs = true
+			case e.end && e.name == "is":
+				inIs = false
+			case !e.start && !e.end && (inV || inIs):
+				cell.WriteString(e.text)
+			}
+		})
+		o.para()
+	}
+	return o.String(), nil
+}
+
+type sheetRef struct{ name, path string }
+
+// xlsxSheets lists a workbook's sheets in their order, with the part each is
+// kept in.
+func xlsxSheets(zr *zip.Reader) ([]sheetRef, error) {
+	wb, err := member(zr, "xl/workbook.xml")
+	if err != nil || wb == nil {
+		return nil, errors.New("not a workbook: no xl/workbook.xml")
+	}
+	rels := map[string]string{}
+	if r, _ := member(zr, "xl/_rels/workbook.xml.rels"); r != nil {
+		_ = walkXML(r, func(e xmlEvent) {
+			if e.start && e.name == "Relationship" {
+				rels[e.get("Id")] = e.get("Target")
+			}
+		})
+	}
+	var out []sheetRef
+	_ = walkXML(wb, func(e xmlEvent) {
+		if !e.start || e.name != "sheet" {
+			return
+		}
+		target := rels[e.relID()]
+		if target == "" {
+			return
+		}
+		p := path.Clean(path.Join("xl", target))
+		if strings.HasPrefix(target, "/") {
+			p = strings.TrimPrefix(target, "/")
+		}
+		out = append(out, sheetRef{name: e.get("name"), path: p})
+	})
+	return out, nil
+}
+
+var slideNum = regexp.MustCompile(`(\d+)\.xml$`)
+
+func numbered(zr *zip.Reader, prefix string) []*zip.File {
+	var fs []*zip.File
+	for _, f := range zr.File {
+		if strings.HasPrefix(f.Name, prefix) && slideNum.MatchString(f.Name) && !strings.Contains(f.Name[len(prefix):], "/") {
+			fs = append(fs, f)
+		}
+	}
+	n := func(f *zip.File) int {
+		v, _ := strconv.Atoi(slideNum.FindStringSubmatch(f.Name)[1])
+		return v
+	}
+	sort.Slice(fs, func(i, j int) bool { return n(fs[i]) < n(fs[j]) })
+	return fs
+}
+
+// rels reads a part's relationships: id → target, and type → target, with
+// targets resolved against the part's directory.
+func rels(zr *zip.Reader, part string) (byID, byType map[string]string) {
+	byID, byType = map[string]string{}, map[string]string{}
+	dir, base := path.Split(part)
+	r, _ := member(zr, dir+"_rels/"+base+".rels")
+	if r == nil {
+		return byID, byType
+	}
+	_ = walkXML(r, func(e xmlEvent) {
+		if !e.start || e.name != "Relationship" || e.get("TargetMode") == "External" {
+			return
+		}
+		t := e.get("Target")
+		if strings.HasPrefix(t, "/") {
+			t = strings.TrimPrefix(t, "/")
+		} else {
+			t = path.Clean(path.Join(dir, t))
+		}
+		byID[e.get("Id")] = t
+		ty := e.get("Type")
+		byType[ty[strings.LastIndex(ty, "/")+1:]] = t
+	})
+	return byID, byType
+}
+
+// pptxText reads a presentation: each slide, in the presentation's order, as
+// a heading, its text, and its speaker notes.
+func pptxText(b []byte) (string, error) {
+	zr, err := openZip(b)
+	if err != nil {
+		return "", err
+	}
+	var order []string
+	if pres, _ := member(zr, "ppt/presentation.xml"); pres != nil {
+		ids, _ := rels(zr, "ppt/presentation.xml")
+		_ = walkXML(pres, func(e xmlEvent) {
+			if e.start && e.name == "sldId" {
+				if t := ids[e.relID()]; t != "" {
+					order = append(order, t)
+				}
+			}
+		})
+	}
+	if len(order) == 0 {
+		for _, f := range numbered(zr, "ppt/slides/slide") {
+			order = append(order, f.Name)
+		}
+	}
+	if len(order) == 0 {
+		return "", errors.New("not a presentation: no slides")
+	}
+	var o out
+	drawing := func(d []byte) {
+		inT, inField := false, 0
+		_ = walkXML(d, func(e xmlEvent) {
+			switch {
+			case e.start && e.name == "fld":
+				// Slide numbers and dates, not the slide's text.
+				inField++
+			case e.end && e.name == "fld":
+				inField--
+			case e.start && e.name == "t":
+				inT = true
+			case e.end && e.name == "t":
+				inT = false
+			case e.end && e.name == "p":
+				o.newline()
+			case e.start && e.name == "br":
+				o.newline()
+			case e.end && e.name == "sp":
+				o.para()
+			case e.end && e.name == "tc":
+				o.tab()
+			case e.end && e.name == "tr":
+				o.newline()
+			case !e.start && !e.end && inT && inField == 0:
+				o.raw(e.text)
+			}
+		})
+	}
+	for i, part := range order {
+		d, err := member(zr, part)
+		if err != nil || d == nil {
+			continue
+		}
+		o.heading(2)
+		o.text(fmt.Sprintf("Slide %d", i+1))
+		o.para()
+		drawing(d)
+		if _, byType := rels(zr, part); byType["notesSlide"] != "" {
+			if nd, _ := member(zr, byType["notesSlide"]); nd != nil {
+				o.para()
+				o.text("Notes:")
+				o.newline()
+				drawing(nd)
+			}
+		}
+		o.para()
+	}
+	return o.String(), nil
+}

internal/kb/extract/rtf.go

@@ -0,0 +1,207 @@
+package extract
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+	"unicode/utf16"
+
+	"golang.org/x/text/encoding/charmap"
+	"golang.org/x/text/unicode/norm"
+)
+
+// rtfSkip are destinations whose content is not the document's text.
+var rtfSkip = map[string]bool{
+	"fonttbl": true, "colortbl": true, "stylesheet": true, "info": true, "pict": true,
+	"header": true, "headerl": true, "headerr": true, "headerf": true, "footer": true,
+	"footerl": true, "footerr": true, "footerf": true, "object": true, "xmlnstbl": true,
+	"listtable": true, "listoverridetable": true, "rsidtbl": true, "generator": true,
+	"themedata": true, "colorschememapping": true, "latentstyles": true, "datastore": true,
+	"filetbl": true, "revtbl": true, "pgdsctbl": true, "fldinst": true, "bkmkstart": true,
+	"bkmkend": true, "shppict": true, "nonshppict": true, "datafield": true, "blipuid": true,
+}
+
+// rtfText reads Rich Text Format: text, paragraphs, tabs and table cells,
+// characters in the document's code page (\ansicpg) or as \u escapes;
+// font tables, pictures, headers and other destinations skipped.
+func rtfText(b []byte) (string, error) {
+	s := string(b)
+	if !strings.HasPrefix(strings.TrimSpace(s), "{\\rtf") {
+		return "", errors.New("not RTF: no {\\rtf header")
+	}
+	type state struct {
+		skip bool
+		uc   int // how many fallback characters follow a \u
+	}
+	cp := charmap.Windows1252
+	stack := []state{{uc: 1}}
+	var o out
+	var pending []byte // \'hh bytes, decoded in runs so a code page's pairs stay together
+	var surrogate rune
+	flush := func() {
+		if len(pending) == 0 {
+			return
+		}
+		d, _ := cp.NewDecoder().Bytes(pending)
+		o.raw(string(d))
+		pending = pending[:0]
+	}
+	skipChars := 0
+	cur := func() *state { return &stack[len(stack)-1] }
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		switch c {
+		case '{':
+			flush()
+			stack = append(stack, *cur())
+		case '}':
+			flush()
+			if len(stack) > 1 {
+				stack = stack[:len(stack)-1]
+			}
+		case '\\':
+			if i+1 >= len(s) {
+				break
+			}
+			n := s[i+1]
+			switch {
+			case n == '\'' && i+3 < len(s):
+				v, err := strconv.ParseUint(s[i+2:i+4], 16, 8)
+				i += 3
+				if err != nil || cur().skip {
+					continue
+				}
+				if skipChars > 0 {
+					skipChars--
+					continue
+				}
+				pending = append(pending, byte(v))
+			case n == '*':
+				i++
+				cur().skip = true
+			case n == '\\' || n == '{' || n == '}':
+				i++
+				if !cur().skip {
+					flush()
+					o.raw(string(n))
+				}
+			case n == '~':
+				i++
+				if !cur().skip {
+					o.raw(" ")
+				}
+			case n == '-' || n == '_':
+				i++
+			case n == '\n' || n == '\r':
+				i++
+				if !cur().skip {
+					flush()
+					o.para()
+				}
+			case isLetter(n):
+				j := i + 1
+				for j < len(s) && isLetter(s[j]) {
+					j++
+				}
+				word := s[i+1 : j]
+				k := j
+				if k < len(s) && (s[k] == '-' || (s[k] >= '0' && s[k] <= '9')) {
+					k++
+					for k < len(s) && s[k] >= '0' && s[k] <= '9' {
+						k++
+					}
+				}
+				arg, hasArg := 0, k > j
+				if hasArg {
+					arg, _ = strconv.Atoi(s[j:k])
+				}
+				if k < len(s) && s[k] == ' ' {
+					k++
+				}
+				i = k - 1
+				flush()
+				if rtfSkip[word] {
+					cur().skip = true
+					continue
+				}
+				switch word {
+				case "ansicpg":
+					cp = codePage(arg)
+				case "uc":
+					cur().uc = arg
+				case "u":
+					if cur().skip {
+						continue
+					}
+					r := rune(arg)
+					if r < 0 {
+						r += 65536
+					}
+					switch {
+					case utf16.IsSurrogate(r) && r < 0xDC00:
+						surrogate = r
+					case utf16.IsSurrogate(r):
+						o.raw(string(utf16.DecodeRune(surrogate, r)))
+						surrogate = 0
+					default:
+						o.raw(string(r))
+					}
+					skipChars = cur().uc
+				case "par", "sect", "page":
+					if !cur().skip {
+						o.para()
+					}
+				case "line":
+					if !cur().skip {
+						o.newline()
+					}
+				case "tab":
+					if !cur().skip {
+						o.raw("\t")
+					}
+				case "cell":
+					if !cur().skip {
+						o.tab()
+					}
+				case "row":
+					if !cur().skip {
+						o.newline()
+					}
+				case "emdash":
+					o.raw("—")
+				case "endash":
+					o.raw("–")
+				case "bullet":
+					o.raw("•")
+				case "lquote", "rquote":
+					o.raw("'")
+				case "ldblquote", "rdblquote":
+					o.raw("\"")
+				}
+			default:
+				i++
+			}
+		case '\r', '\n':
+			// Line breaks in RTF source are not text.
+		default:
+			if cur().skip {
+				continue
+			}
+			if skipChars > 0 {
+				skipChars--
+				continue
+			}
+			if c >= 0x80 {
+				// Unescaped 8-bit text, as some writers leave it.
+				pending = append(pending, c)
+				continue
+			}
+			flush()
+			o.raw(string(c))
+		}
+	}
+	flush()
+	return norm.NFC.String(o.String()), nil
+}
+
+func isLetter(c byte) bool { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') }

internal/kb/extract/text.go

@@ -0,0 +1,95 @@
+package extract
+
+import (
+	"bytes"
+	"strings"
+	"unicode/utf8"
+
+	"golang.org/x/net/html/charset"
+	"golang.org/x/text/encoding/charmap"
+	"golang.org/x/text/encoding/unicode"
+	"golang.org/x/text/unicode/norm"
+)
+
+func hasUTF16BOM(b []byte) bool {
+	return len(b) >= 2 && ((b[0] == 0xFF && b[1] == 0xFE) || (b[0] == 0xFE && b[1] == 0xFF))
+}
+
+// decodeText turns a text file into UTF-8, NFC.
+//
+// UTF-8 is taken as it is (its BOM dropped); UTF-16 by its BOM, which is how
+// Windows' Notepad writes "Unicode". Anything else is a single-byte code
+// page, and which one cannot be known from the bytes; Windows-1254 is
+// assumed, since it is what a Turkish Windows writes and it agrees with
+// Windows-1252 on every letter but six (ğĞıİşŞ in place of ðÐýÝþÞ) — which
+// are rare in the western languages 1252 serves.
+func decodeText(b []byte) string {
+	var s string
+	switch {
+	case bytes.HasPrefix(b, []byte{0xEF, 0xBB, 0xBF}):
+		s = string(b[3:])
+	case hasUTF16BOM(b):
+		out, err := unicode.UTF16(unicode.LittleEndian, unicode.ExpectBOM).NewDecoder().Bytes(b)
+		if err != nil {
+			return ""
+		}
+		s = string(out)
+	case utf8.Valid(b):
+		s = string(b)
+	default:
+		out, err := charmap.Windows1254.NewDecoder().Bytes(b)
+		if err != nil {
+			return ""
+		}
+		s = string(out)
+	}
+	return norm.NFC.String(strings.ReplaceAll(s, "\r\n", "\n"))
+}
+
+// decodeCharset decodes bytes declared to be in a charset, as mail and web
+// pages declare theirs, by any of the WHATWG labels; an unknown or missing
+// one is treated as decodeText would.
+func decodeCharset(b []byte, cs string) string {
+	cs = strings.ToLower(strings.TrimSpace(cs))
+	if cs == "" || cs == "utf-8" || cs == "utf8" || cs == "us-ascii" {
+		return decodeText(b)
+	}
+	enc, _ := charset.Lookup(cs)
+	if enc == nil {
+		return decodeText(b)
+	}
+	out, err := enc.NewDecoder().Bytes(b)
+	if err != nil {
+		return decodeText(b)
+	}
+	return norm.NFC.String(strings.ReplaceAll(string(out), "\r\n", "\n"))
+}
+
+// codePage is the decoder for an RTF \ansicpgN or a Windows code page number.
+func codePage(n int) *charmap.Charmap {
+	switch n {
+	case 1250:
+		return charmap.Windows1250
+	case 1251:
+		return charmap.Windows1251
+	case 1252:
+		return charmap.Windows1252
+	case 1253:
+		return charmap.Windows1253
+	case 1254:
+		return charmap.Windows1254
+	case 1255:
+		return charmap.Windows1255
+	case 1256:
+		return charmap.Windows1256
+	case 1257:
+		return charmap.Windows1257
+	case 1258:
+		return charmap.Windows1258
+	case 850:
+		return charmap.CodePage850
+	case 437:
+		return charmap.CodePage437
+	}
+	return charmap.Windows1252
+}

internal/kb/kbsync/api.go

@@ -0,0 +1,246 @@
+package kbsync
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Client speaks to a gateway's knowledge-base and embeddings endpoints with
+// a person's key.
+type Client struct {
+	// Base is the gateway's address, "https://llm.example.com".
+	Base string
+	Key  string
+	// Project is the project a personal key acts in.
+	Project string
+	HTTP    *http.Client
+	// Wait is how long a request waits out a model loading or a busy
+	// gateway (429/503 with Retry-After) before giving up; 0 is 15 minutes.
+	Wait time.Duration
+	// Waiting, when set, is told each time a request waits, and why.
+	Waiting func(why string, d time.Duration)
+}
+
+// NewHTTP is an HTTP client trusting the system's certificates, and those in
+// caFile when one is given.
+func NewHTTP(caFile string) (*http.Client, error) {
+	tr := http.DefaultTransport.(*http.Transport).Clone()
+	if caFile != "" {
+		pem, err := os.ReadFile(caFile)
+		if err != nil {
+			return nil, err
+		}
+		pool, err := x509.SystemCertPool()
+		if err != nil || pool == nil {
+			pool = x509.NewCertPool()
+		}
+		if !pool.AppendCertsFromPEM(pem) {
+			return nil, fmt.Errorf("no certificate in %s", caFile)
+		}
+		tr.TLSClientConfig = &tls.Config{RootCAs: pool, MinVersion: tls.VersionTLS12}
+	}
+	return &http.Client{Transport: tr, Timeout: 10 * time.Minute}, nil
+}
+
+// Collection is a collection as the gateway shows it to this key.
+type Collection struct {
+	ID         string `json:"id"`
+	Name       string `json:"name"`
+	Owner      string `json:"owner"`
+	OwnerName  string `json:"owner_name"`
+	EmbedModel string `json:"embed_model"`
+	Dims       int    `json:"dims"`
+	Writable   bool   `json:"writable"`
+}
+
+// RemoteDoc is a document the collection holds.
+type RemoteDoc struct {
+	Name    string    `json:"name"`
+	Digest  string    `json:"digest"`
+	Bytes   int64     `json:"bytes"`
+	Chunks  int       `json:"chunks"`
+	AddedAt time.Time `json:"added_at"`
+}
+
+// Manifest is a collection and its documents.
+type Manifest struct {
+	Collection Collection  `json:"collection"`
+	Documents  []RemoteDoc `json:"documents"`
+}
+
+// ChunkOut is one chunk as sent.
+type ChunkOut struct {
+	Text      string    `json:"text"`
+	Embedding []float32 `json:"embedding"`
+}
+
+// DocOut is one document as sent.
+type DocOut struct {
+	Name   string     `json:"name"`
+	Digest string     `json:"digest"`
+	Bytes  int64      `json:"bytes"`
+	Chunks []ChunkOut `json:"chunks"`
+}
+
+// APIError is an answer that was not a success.
+type APIError struct {
+	Status  int
+	Message string
+}
+
+func (e *APIError) Error() string { return fmt.Sprintf("%d: %s", e.Status, e.Message) }
+
+// do sends a request and decodes a JSON answer into out, waiting out answers
+// that say to retry.
+func (c *Client) do(ctx context.Context, method, path string, body any, out any) error {
+	var payload []byte
+	if body != nil {
+		var err error
+		if payload, err = json.Marshal(body); err != nil {
+			return err
+		}
+	}
+	wait := c.Wait
+	if wait <= 0 {
+		wait = 15 * time.Minute
+	}
+	deadline := time.Now().Add(wait)
+	for {
+		req, err := http.NewRequestWithContext(ctx, method, strings.TrimRight(c.Base, "/")+path, bytes.NewReader(payload))
+		if err != nil {
+			return err
+		}
+		req.Header.Set("Authorization", "Bearer "+c.Key)
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("User-Agent", "llmgw-kb")
+		if c.Project != "" {
+			req.Header.Set("X-Llmgw-Project", c.Project)
+		}
+		res, err := c.HTTP.Do(req)
+		if err != nil {
+			return err
+		}
+		data, err := io.ReadAll(io.LimitReader(res.Body, 256<<20))
+		res.Body.Close()
+		if err != nil {
+			return err
+		}
+		if res.StatusCode < 300 {
+			if out == nil {
+				return nil
+			}
+			return json.Unmarshal(data, out)
+		}
+		retry := res.Header.Get("Retry-After")
+		if retry != "" && (res.StatusCode == http.StatusTooManyRequests || res.StatusCode >= 500) && time.Now().Before(deadline) {
+			secs, _ := strconv.Atoi(retry)
+			d := time.Duration(max(secs, 1)) * time.Second
+			if c.Waiting != nil {
+				c.Waiting(errorMessage(data, res.Status), d)
+			}
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-time.After(d):
+			}
+			continue
+		}
+		return &APIError{Status: res.StatusCode, Message: errorMessage(data, res.Status)}
+	}
+}
+
+// errorMessage is the message in an OpenAI-shaped error, or the body.
+func errorMessage(data []byte, status string) string {
+	var e struct {
+		Error struct {
+			Message string `json:"message"`
+		} `json:"error"`
+	}
+	if json.Unmarshal(data, &e) == nil && e.Error.Message != "" {
+		return e.Error.Message
+	}
+	if s := strings.TrimSpace(string(data)); s != "" && len(s) < 500 {
+		return s
+	}
+	return status
+}
+
+// Collections lists what this key may read.
+func (c *Client) Collections(ctx context.Context) ([]Collection, error) {
+	var out struct {
+		Data []Collection `json:"data"`
+	}
+	err := c.do(ctx, http.MethodGet, "/v1/kb/collections", nil, &out)
+	return out.Data, err
+}
+
+// Manifest reads a collection's documents, by its name or id.
+func (c *Client) Manifest(ctx context.Context, collection string) (Manifest, error) {
+	var m Manifest
+	err := c.do(ctx, http.MethodGet, "/v1/kb/collections/"+url.PathEscape(collection)+"/manifest", nil, &m)
+	return m, err
+}
+
+// Put sends a document; changed is false when the collection already had it.
+func (c *Client) Put(ctx context.Context, collection string, d DocOut) (bool, error) {
+	var out struct {
+		Changed bool `json:"changed"`
+	}
+	err := c.do(ctx, http.MethodPut, "/v1/kb/collections/"+url.PathEscape(collection)+"/documents", d, &out)
+	return out.Changed, err
+}
+
+// Delete removes a document; one already gone is not an error.
+func (c *Client) Delete(ctx context.Context, collection, name string) error {
+	err := c.do(ctx, http.MethodDelete, "/v1/kb/collections/"+url.PathEscape(collection)+"/documents?name="+url.QueryEscape(name), nil, nil)
+	var ae *APIError
+	if errors.As(err, &ae) && ae.Status == http.StatusNotFound && strings.HasPrefix(ae.Message, "no document") {
+		return nil
+	}
+	return err
+}
+
+// embedBatch is how many chunks go in one embeddings request.
+const embedBatch = 32
+
+// Embed has the gateway embed texts with a model, in batches, in order.
+func (c *Client) Embed(ctx context.Context, model string, texts []string) ([][]float32, error) {
+	out := make([][]float32, 0, len(texts))
+	for start := 0; start < len(texts); start += embedBatch {
+		end := min(start+embedBatch, len(texts))
+		var res struct {
+			Data []struct {
+				Index     int       `json:"index"`
+				Embedding []float32 `json:"embedding"`
+			} `json:"data"`
+		}
+		if err := c.do(ctx, http.MethodPost, "/v1/embeddings",
+			map[string]any{"model": model, "input": texts[start:end], "encoding_format": "float"}, &res); err != nil {
+			return nil, err
+		}
+		if len(res.Data) != end-start {
+			return nil, fmt.Errorf("the gateway embedded %d of %d texts", len(res.Data), end-start)
+		}
+		batch := make([][]float32, end-start)
+		for _, d := range res.Data {
+			if d.Index < 0 || d.Index >= len(batch) {
+				return nil, fmt.Errorf("an embedding came back with index %d", d.Index)
+			}
+			batch[d.Index] = d.Embedding
+		}
+		out = append(out, batch...)
+	}
+	return out, nil
+}

internal/kb/kbsync/ledger.go

@@ -0,0 +1,222 @@
+// Package kbsync is llmgw-kb's work (BACKLOG F2): it finds a person's
+// documents, keeps a ledger of what it has done with each, and sends a
+// knowledge base only what changed — text and vectors, never the files.
+package kbsync
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	_ "modernc.org/sqlite" // pure Go, so the client builds for every system
+)
+
+// Ledger is the record, on this machine, of every document sent or skipped:
+// which file it came from, its size, modification time and digest, and what
+// happened. A file whose size and time have not changed is not read again to
+// learn that it has not changed, and --delete removes only what this
+// machine sent.
+type Ledger struct {
+	db *sql.DB
+}
+
+// State is what happened to a document.
+type State string
+
+// The states a document is left in.
+const (
+	Sent    State = "sent"
+	Skipped State = "skipped"
+	Failed  State = "failed"
+)
+
+// Entry is one document in the ledger.
+type Entry struct {
+	Gateway    string
+	Collection string
+	// Name is the document's name in the collection.
+	Name string
+	// File is the path on disk it came from, absolute.
+	File   string
+	Size   int64
+	MTime  time.Time
+	Digest string
+	State  State
+	Reason string
+	Chunks int
+	At     time.Time
+}
+
+// Run is one sync, for history.
+type Run struct {
+	ID                                       int64
+	Gateway, Collection                      string
+	Started, Finished                        time.Time
+	Sent, Unchanged, Skipped, Failed, Delete int
+}
+
+// DefaultLedgerPath is where the ledger is kept: the user's configuration
+// directory, which, unlike a cache directory, nothing cleans up.
+func DefaultLedgerPath() (string, error) {
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "llmgw-kb", "ledger.db"), nil
+}
+
+const ledgerSchema = `
+CREATE TABLE IF NOT EXISTS documents (
+  gateway    TEXT NOT NULL,
+  collection TEXT NOT NULL,
+  name       TEXT NOT NULL,
+  file       TEXT NOT NULL,
+  size       INTEGER NOT NULL,
+  mtime_ns   INTEGER NOT NULL,
+  digest     TEXT NOT NULL,
+  state      TEXT NOT NULL,
+  reason     TEXT NOT NULL DEFAULT '',
+  chunks     INTEGER NOT NULL DEFAULT 0,
+  at_ms      INTEGER NOT NULL,
+  PRIMARY KEY (gateway, collection, name)
+);
+CREATE INDEX IF NOT EXISTS documents_by_file ON documents (file);
+CREATE TABLE IF NOT EXISTS runs (
+  id         INTEGER PRIMARY KEY AUTOINCREMENT,
+  gateway    TEXT NOT NULL,
+  collection TEXT NOT NULL,
+  started_ms INTEGER NOT NULL,
+  ended_ms   INTEGER NOT NULL DEFAULT 0,
+  sent       INTEGER NOT NULL DEFAULT 0,
+  unchanged  INTEGER NOT NULL DEFAULT 0,
+  skipped    INTEGER NOT NULL DEFAULT 0,
+  failed     INTEGER NOT NULL DEFAULT 0,
+  deleted    INTEGER NOT NULL DEFAULT 0
+);`
+
+// OpenLedger opens (creating) the ledger at a path.
+func OpenLedger(ctx context.Context, path string) (*Ledger, error) {
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		return nil, err
+	}
+	// WAL and a busy timeout: two syncs at once, from two terminals, wait
+	// for each other rather than failing.
+	db, err := sql.Open("sqlite", path+"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(10000)&_pragma=synchronous(NORMAL)")
+	if err != nil {
+		return nil, err
+	}
+	db.SetMaxOpenConns(1)
+	if _, err := db.ExecContext(ctx, ledgerSchema); err != nil {
+		_ = db.Close()
+		return nil, fmt.Errorf("opening the ledger %s: %w", path, err)
+	}
+	_ = os.Chmod(path, 0o600)
+	return &Ledger{db: db}, nil
+}
+
+// Close closes the ledger.
+func (l *Ledger) Close() error { return l.db.Close() }
+
+const entryCols = `gateway, collection, name, file, size, mtime_ns, digest, state, reason, chunks, at_ms`
+
+func scanEntry(sc interface{ Scan(...any) error }) (Entry, error) {
+	var e Entry
+	var mtime, at int64
+	var state string
+	err := sc.Scan(&e.Gateway, &e.Collection, &e.Name, &e.File, &e.Size, &mtime, &e.Digest, &state, &e.Reason, &e.Chunks, &at)
+	e.MTime, e.At, e.State = time.Unix(0, mtime), time.UnixMilli(at), State(state)
+	return e, err
+}
+
+// Put records what happened to a document.
+func (l *Ledger) Put(ctx context.Context, e Entry) error {
+	if e.At.IsZero() {
+		e.At = time.Now()
+	}
+	_, err := l.db.ExecContext(ctx, `INSERT INTO documents (`+entryCols+`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		ON CONFLICT (gateway, collection, name) DO UPDATE SET file = excluded.file, size = excluded.size,
+		  mtime_ns = excluded.mtime_ns, digest = excluded.digest, state = excluded.state,
+		  reason = excluded.reason, chunks = excluded.chunks, at_ms = excluded.at_ms`,
+		e.Gateway, e.Collection, e.Name, e.File, e.Size, e.MTime.UnixNano(), e.Digest, string(e.State),
+		e.Reason, e.Chunks, e.At.UnixMilli())
+	return err
+}
+
+// Remove forgets a document.
+func (l *Ledger) Remove(ctx context.Context, gateway, collection, name string) error {
+	_, err := l.db.ExecContext(ctx, `DELETE FROM documents WHERE gateway = ? AND collection = ? AND name = ?`,
+		gateway, collection, name)
+	return err
+}
+
+// Entries lists a collection's documents as this machine left them.
+func (l *Ledger) Entries(ctx context.Context, gateway, collection string) ([]Entry, error) {
+	rows, err := l.db.QueryContext(ctx, `SELECT `+entryCols+` FROM documents WHERE gateway = ? AND collection = ? ORDER BY name`,
+		gateway, collection)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Entry
+	for rows.Next() {
+		e, err := scanEntry(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, e)
+	}
+	return out, rows.Err()
+}
+
+// Known is the digest the ledger has for a file of this size and time, from
+// any collection: a file is hashed once however many collections it goes to.
+func (l *Ledger) Known(ctx context.Context, file string, size int64, mtime time.Time) (string, bool) {
+	var d string
+	err := l.db.QueryRowContext(ctx, `SELECT digest FROM documents WHERE file = ? AND size = ? AND mtime_ns = ? LIMIT 1`,
+		file, size, mtime.UnixNano()).Scan(&d)
+	return d, err == nil
+}
+
+// StartRun records that a sync began.
+func (l *Ledger) StartRun(ctx context.Context, gateway, collection string) (int64, error) {
+	res, err := l.db.ExecContext(ctx, `INSERT INTO runs (gateway, collection, started_ms) VALUES (?, ?, ?)`,
+		gateway, collection, time.Now().UnixMilli())
+	if err != nil {
+		return 0, err
+	}
+	return res.LastInsertId()
+}
+
+// EndRun records how a sync ended.
+func (l *Ledger) EndRun(ctx context.Context, id int64, r Run) error {
+	_, err := l.db.ExecContext(ctx, `UPDATE runs SET ended_ms = ?, sent = ?, unchanged = ?, skipped = ?, failed = ?, deleted = ?
+		WHERE id = ?`, time.Now().UnixMilli(), r.Sent, r.Unchanged, r.Skipped, r.Failed, r.Delete, id)
+	return err
+}
+
+// Runs lists the latest syncs, newest first.
+func (l *Ledger) Runs(ctx context.Context, limit int) ([]Run, error) {
+	rows, err := l.db.QueryContext(ctx, `SELECT id, gateway, collection, started_ms, ended_ms, sent, unchanged, skipped, failed, deleted
+		FROM runs ORDER BY id DESC LIMIT ?`, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Run
+	for rows.Next() {
+		var r Run
+		var s, e int64
+		if err := rows.Scan(&r.ID, &r.Gateway, &r.Collection, &s, &e, &r.Sent, &r.Unchanged, &r.Skipped, &r.Failed, &r.Delete); err != nil {
+			return nil, err
+		}
+		r.Started = time.UnixMilli(s)
+		if e > 0 {
+			r.Finished = time.UnixMilli(e)
+		}
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}

internal/kb/kbsync/sync.go

@@ -0,0 +1,574 @@
+package kbsync
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/text/unicode/norm"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/chunk"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/extract"
+)
+
+// Options say what to sync and how.
+type Options struct {
+	// Collection is the collection's name or id.
+	Collection string
+	// Roots are the directories and files to sync.
+	Roots []string
+	// Include, when set, are the only files read (globs; one without a "/"
+	// matches a file's name, one with it the path under its root, "**"
+	// crossing directories). Exclude are never read.
+	Include, Exclude []string
+	// Hidden includes files and directories whose names start with a dot.
+	Hidden bool
+	// DryRun reads and cuts everything that would be sent, and sends
+	// nothing.
+	DryRun bool
+	// Delete removes from the collection documents this machine sent whose
+	// files under these roots are gone.
+	Delete bool
+	// Retry reads again files skipped before, as when a helper has been
+	// installed since.
+	Retry bool
+	// Workers is how many files are read and sent at once; 0 is 4.
+	Workers int
+	Extract extract.Options
+	Chunk   chunk.Options
+}
+
+// Event is something a sync did to one document, for showing progress.
+type Event struct {
+	// Kind is sent, unchanged, skipped, failed, deleted, would-send,
+	// would-delete, or warning.
+	Kind   string
+	Name   string
+	Detail string
+	Chunks int
+	Bytes  int64
+}
+
+// Report is what a sync did in all.
+type Report struct {
+	Collection Collection
+	Files      int
+	Sent       int
+	Unchanged  int
+	Skipped    int
+	Failed     int
+	Deleted    int
+	// Chunks and Bytes are what was sent, or with DryRun what would be.
+	Chunks int
+	Bytes  int64
+}
+
+// maxDocJSON is the most one document's request is, under the gateway's
+// limit with room to spare.
+const maxDocJSON = 60 << 20
+
+// defaultExcludes are directories nobody means to put in a knowledge base.
+var defaultExcludes = map[string]bool{
+	".git": true, ".svn": true, ".hg": true, "node_modules": true, ".venv": true, "venv": true,
+	"__pycache__": true, ".idea": true, ".vscode": true, "$RECYCLE.BIN": true,
+	"System Volume Information": true, ".Trash": true, ".Trashes": true, ".cache": true,
+}
+
+type file struct {
+	abs   string
+	name  string
+	size  int64
+	mtime time.Time
+}
+
+// Sync brings a collection up to date with the files under the roots.
+func Sync(ctx context.Context, c *Client, l *Ledger, o Options, progress func(Event)) (Report, error) {
+	var mu sync.Mutex
+	var rep Report
+	emit := func(e Event) {
+		mu.Lock()
+		defer mu.Unlock()
+		switch e.Kind {
+		case "sent", "would-send":
+			rep.Sent++
+			rep.Chunks += e.Chunks
+			rep.Bytes += e.Bytes
+		case "unchanged":
+			rep.Unchanged++
+		case "skipped":
+			rep.Skipped++
+		case "failed":
+			rep.Failed++
+		case "deleted", "would-delete":
+			rep.Deleted++
+		}
+		if progress != nil {
+			progress(e)
+		}
+	}
+
+	m, err := c.Manifest(ctx, o.Collection)
+	if err != nil {
+		return rep, fmt.Errorf("reading collection %s: %w", o.Collection, err)
+	}
+	rep.Collection = m.Collection
+	if !m.Collection.Writable && !o.DryRun {
+		return rep, fmt.Errorf("this key may read collection %s but not add to it", m.Collection.Name)
+	}
+	remote, chunks := map[string]string{}, map[string]int{}
+	for _, d := range m.Documents {
+		remote[d.Name], chunks[d.Name] = d.Digest, d.Chunks
+	}
+	gw := strings.TrimRight(c.Base, "/")
+	coll := m.Collection.ID
+
+	files, roots, err := walk(o, func(name, why string) { emit(Event{Kind: "warning", Name: name, Detail: why}) })
+	if err != nil {
+		return rep, err
+	}
+	rep.Files = len(files)
+	if len(files) == 0 {
+		return rep, ErrNothing
+	}
+
+	runID, err := l.StartRun(ctx, gw, coll)
+	if err != nil {
+		return rep, err
+	}
+	previous, err := l.Entries(ctx, gw, coll)
+	if err != nil {
+		return rep, err
+	}
+	byFile := map[string][]Entry{}
+	for _, e := range previous {
+		byFile[e.File] = append(byFile[e.File], e)
+	}
+
+	s := &syncer{c: c, l: l, o: o, gw: gw, coll: m.Collection, remote: remote, chunks: chunks, byFile: byFile, emit: emit}
+	workers := o.Workers
+	if workers <= 0 {
+		workers = 4
+	}
+	jobs := make(chan file)
+	var wg sync.WaitGroup
+	for range workers {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for f := range jobs {
+				s.one(ctx, f)
+			}
+		}()
+	}
+	for _, f := range files {
+		select {
+		case jobs <- f:
+		case <-ctx.Done():
+		}
+		if ctx.Err() != nil {
+			break
+		}
+	}
+	close(jobs)
+	wg.Wait()
+
+	if o.Delete && ctx.Err() == nil {
+		seen := map[string]bool{}
+		for _, f := range files {
+			seen[f.abs] = true
+		}
+		for _, e := range previous {
+			if e.State != Sent || seen[e.File] || !under(e.File, roots) {
+				continue
+			}
+			if o.DryRun {
+				emit(Event{Kind: "would-delete", Name: e.Name})
+				continue
+			}
+			if err := c.Delete(ctx, coll, e.Name); err != nil {
+				emit(Event{Kind: "failed", Name: e.Name, Detail: "deleting: " + err.Error()})
+				continue
+			}
+			_ = l.Remove(ctx, gw, coll, e.Name)
+			emit(Event{Kind: "deleted", Name: e.Name})
+		}
+	}
+	_ = l.EndRun(context.WithoutCancel(ctx), runID, Run{Sent: rep.Sent, Unchanged: rep.Unchanged, Skipped: rep.Skipped,
+		Failed: rep.Failed, Delete: rep.Deleted})
+	return rep, ctx.Err()
+}
+
+type syncer struct {
+	c      *Client
+	l      *Ledger
+	o      Options
+	gw     string
+	coll   Collection
+	remote map[string]string
+	chunks map[string]int
+	byFile map[string][]Entry
+	emit   func(Event)
+}
+
+func (s *syncer) entry(f file, name, digest string, st State, reason string, chunks int) Entry {
+	return Entry{Gateway: s.gw, Collection: s.coll.ID, Name: name, File: f.abs, Size: f.size, MTime: f.mtime,
+		Digest: digest, State: st, Reason: reason, Chunks: chunks}
+}
+
+// one syncs one file: every document in it.
+func (s *syncer) one(ctx context.Context, f file) {
+	if ctx.Err() != nil {
+		return
+	}
+	digest, ok := s.l.Known(ctx, f.abs, f.size, f.mtime)
+	if !ok {
+		d, err := hashFile(f.abs)
+		if err != nil {
+			s.emit(Event{Kind: "skipped", Name: f.name, Detail: err.Error()})
+			return
+		}
+		digest = d
+	}
+	prev := s.byFile[f.abs]
+
+	// The collection has this file as it is: nothing to read.
+	if s.remote[f.name] == digest {
+		s.record(ctx, s.entry(f, f.name, digest, Sent, "", s.chunks[f.name]))
+		s.emit(Event{Kind: "unchanged", Name: f.name})
+		return
+	}
+	// An archive or a mail is several documents; all of them as they are
+	// is nothing to read either.
+	if len(prev) > 0 && allSame(prev, digest, s.remote) && !(s.o.Retry && anySkipped(prev)) {
+		for _, e := range prev {
+			if e.State == Skipped {
+				s.emit(Event{Kind: "skipped", Name: e.Name, Detail: e.Reason + " (as before; --retry reads it again)"})
+			} else {
+				s.emit(Event{Kind: "unchanged", Name: e.Name})
+			}
+		}
+		return
+	}
+
+	parts, err := extract.File(ctx, f.abs, s.o.Extract)
+	if err != nil {
+		s.skip(ctx, f, f.name, digest, err)
+		return
+	}
+	current := map[string]bool{}
+	for _, p := range parts {
+		name := f.name
+		if p.Name != "" {
+			name = f.name + "!/" + p.Name
+		}
+		current[name] = true
+		if p.Err != nil {
+			s.skip(ctx, f, name, digest, p.Err)
+			continue
+		}
+		s.send(ctx, f, name, digest, p.Text)
+	}
+	// Members an archive no longer has go with it.
+	for _, e := range prev {
+		if current[e.Name] || e.Name == f.name {
+			continue
+		}
+		if s.o.DryRun {
+			s.emit(Event{Kind: "would-delete", Name: e.Name, Detail: "no longer in " + f.name})
+			continue
+		}
+		if e.State == Sent {
+			if err := s.c.Delete(ctx, s.coll.ID, e.Name); err != nil {
+				s.emit(Event{Kind: "failed", Name: e.Name, Detail: "deleting: " + err.Error()})
+				continue
+			}
+			s.emit(Event{Kind: "deleted", Name: e.Name, Detail: "no longer in " + f.name})
+		}
+		_ = s.l.Remove(ctx, s.gw, s.coll.ID, e.Name)
+	}
+}
+
+// allSame reports whether every document from a file was left with this
+// digest, and the collection still holds those that were sent.
+func allSame(prev []Entry, digest string, remote map[string]string) bool {
+	for _, e := range prev {
+		if e.Digest != digest {
+			return false
+		}
+		switch e.State {
+		case Sent:
+			if remote[e.Name] != digest {
+				return false
+			}
+		case Failed:
+			return false
+		}
+	}
+	return true
+}
+
+func anySkipped(es []Entry) bool {
+	for _, e := range es {
+		if e.State == Skipped {
+			return true
+		}
+	}
+	return false
+}
+
+func (s *syncer) skip(ctx context.Context, f file, name, digest string, err error) {
+	s.record(ctx, s.entry(f, name, digest, Skipped, err.Error(), 0))
+	s.emit(Event{Kind: "skipped", Name: name, Detail: err.Error()})
+}
+
+// record writes the ledger; a dry run leaves it as it was.
+func (s *syncer) record(ctx context.Context, e Entry) {
+	if s.o.DryRun {
+		return
+	}
+	_ = s.l.Put(ctx, e)
+}
+
+// send cuts a document's text, embeds it and sends it.
+func (s *syncer) send(ctx context.Context, f file, name, digest, text string) {
+	if s.remote[name] == digest {
+		s.record(ctx, s.entry(f, name, digest, Sent, "", s.chunks[name]))
+		s.emit(Event{Kind: "unchanged", Name: name})
+		return
+	}
+	cs := chunk.Split(text, s.o.Chunk)
+	if len(cs) == 0 {
+		s.skip(ctx, f, name, digest, extract.ErrNoText)
+		return
+	}
+	texts := make([]string, len(cs))
+	var size int64
+	for i, c := range cs {
+		texts[i] = c.Text()
+		size += int64(len(texts[i]))
+	}
+	// About ten bytes of JSON a dimension.
+	size += int64(len(cs) * s.coll.Dims * 10)
+	if size > maxDocJSON {
+		s.fail(ctx, f, name, digest, fmt.Errorf("%d MiB to send is over the gateway's limit for one document; split the file", size>>20))
+		return
+	}
+	if s.o.DryRun {
+		s.emit(Event{Kind: "would-send", Name: name, Chunks: len(cs), Bytes: size})
+		return
+	}
+	vecs, err := s.c.Embed(ctx, s.coll.EmbedModel, texts)
+	if err != nil {
+		s.fail(ctx, f, name, digest, fmt.Errorf("embedding with %s: %w", s.coll.EmbedModel, err))
+		return
+	}
+	out := DocOut{Name: name, Digest: digest, Bytes: f.size, Chunks: make([]ChunkOut, len(cs))}
+	for i := range cs {
+		if len(vecs[i]) != s.coll.Dims {
+			s.fail(ctx, f, name, digest, fmt.Errorf("%s gave %d dimensions and the collection takes %d",
+				s.coll.EmbedModel, len(vecs[i]), s.coll.Dims))
+			return
+		}
+		out.Chunks[i] = ChunkOut{Text: texts[i], Embedding: vecs[i]}
+	}
+	if _, err := s.c.Put(ctx, s.coll.ID, out); err != nil {
+		s.fail(ctx, f, name, digest, err)
+		return
+	}
+	s.record(ctx, s.entry(f, name, digest, Sent, "", len(cs)))
+	s.emit(Event{Kind: "sent", Name: name, Chunks: len(cs), Bytes: size})
+}
+
+func (s *syncer) fail(ctx context.Context, f file, name, digest string, err error) {
+	s.record(ctx, s.entry(f, name, digest, Failed, err.Error(), 0))
+	s.emit(Event{Kind: "failed", Name: name, Detail: err.Error()})
+}
+
+func hashFile(p string) (string, error) {
+	fh, err := os.Open(p)
+	if err != nil {
+		return "", err
+	}
+	defer fh.Close()
+	h := sha256.New()
+	if _, err := io.Copy(h, fh); err != nil {
+		return "", err
+	}
+	return "sha256:" + hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// under reports whether a path is one of the roots or inside one.
+func under(p string, roots []string) bool {
+	for _, r := range roots {
+		if p == r || strings.HasPrefix(p, strings.TrimRight(r, string(filepath.Separator))+string(filepath.Separator)) {
+			return true
+		}
+	}
+	return false
+}
+
+// walk lists the files to sync, named as documents: the path under its root
+// with forward slashes, in Unicode NFC, prefixed by the root's own name when
+// there are several roots so that two roots' "README.md" stay apart.
+func walk(o Options, warn func(name, why string)) ([]file, []string, error) {
+	inc, err := globs(o.Include)
+	if err != nil {
+		return nil, nil, err
+	}
+	exc, err := globs(o.Exclude)
+	if err != nil {
+		return nil, nil, err
+	}
+	var out []file
+	var roots []string
+	seen := map[string]string{}
+	for _, root := range o.Roots {
+		abs, err := filepath.Abs(root)
+		if err != nil {
+			return nil, nil, err
+		}
+		st, err := os.Stat(abs)
+		if err != nil {
+			return nil, nil, err
+		}
+		roots = append(roots, abs)
+		prefix := ""
+		if len(o.Roots) > 1 && st.IsDir() {
+			prefix = norm.NFC.String(filepath.Base(abs)) + "/"
+		}
+		add := func(p string, info fs.FileInfo) {
+			rel := filepath.Base(p)
+			if st.IsDir() {
+				rel, _ = filepath.Rel(abs, p)
+			}
+			name := prefix + norm.NFC.String(filepath.ToSlash(rel))
+			if !wanted(name, inc, exc, o.Hidden) {
+				return
+			}
+			if prev, ok := seen[strings.ToLower(name)]; ok && prev != name {
+				warn(name, "differs from "+prev+" only in case; on Windows and macOS they are one file")
+			}
+			seen[strings.ToLower(name)] = name
+			out = append(out, file{abs: p, name: name, size: info.Size(), mtime: info.ModTime()})
+		}
+		if !st.IsDir() {
+			add(abs, st)
+			continue
+		}
+		err = filepath.WalkDir(abs, func(p string, d fs.DirEntry, err error) error {
+			if err != nil {
+				// A directory this user may not read is skipped, not fatal.
+				warn(p, err.Error())
+				if d != nil && d.IsDir() {
+					return filepath.SkipDir
+				}
+				return nil
+			}
+			base := d.Name()
+			if d.IsDir() {
+				if p != abs && (defaultExcludes[base] || (!o.Hidden && strings.HasPrefix(base, "."))) {
+					return filepath.SkipDir
+				}
+				return nil
+			}
+			if !d.Type().IsRegular() {
+				return nil
+			}
+			info, err := d.Info()
+			if err != nil {
+				return nil
+			}
+			add(p, info)
+			return nil
+		})
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].name < out[j].name })
+	return out, roots, nil
+}
+
+// wanted applies the filters to a document name.
+func wanted(name string, inc, exc []*regexp.Regexp, hidden bool) bool {
+	base := path.Base(name)
+	if !hidden && strings.HasPrefix(base, ".") {
+		return false
+	}
+	// Office's lock files, LibreOffice's, editors' backups.
+	if strings.HasPrefix(base, "~$") || strings.HasPrefix(base, ".~lock.") || strings.HasSuffix(base, "~") ||
+		base == "Thumbs.db" || base == "desktop.ini" || base == ".DS_Store" {
+		return false
+	}
+	for _, re := range exc {
+		if re.MatchString(name) || re.MatchString(base) {
+			return false
+		}
+	}
+	if len(inc) > 0 {
+		for _, re := range inc {
+			if re.MatchString(name) || re.MatchString(base) {
+				return true
+			}
+		}
+		return false
+	}
+	return extract.Known(base)
+}
+
+// globs compiles glob patterns: "*" within a name, "**" across directories,
+// "?" one character; case-insensitive, as names are on Windows and macOS.
+func globs(patterns []string) ([]*regexp.Regexp, error) {
+	var out []*regexp.Regexp
+	for _, p := range patterns {
+		for _, one := range strings.Split(p, ",") {
+			one = strings.TrimSpace(filepath.ToSlash(one))
+			if one == "" {
+				continue
+			}
+			var b strings.Builder
+			b.WriteString("(?i)^")
+			for i := 0; i < len(one); i++ {
+				switch c := one[i]; c {
+				case '*':
+					if i+1 < len(one) && one[i+1] == '*' {
+						b.WriteString(".*")
+						i++
+						if i+1 < len(one) && one[i+1] == '/' {
+							b.WriteString("/?")
+							i++
+						}
+					} else {
+						b.WriteString("[^/]*")
+					}
+				case '?':
+					b.WriteString("[^/]")
+				default:
+					b.WriteString(regexp.QuoteMeta(string(c)))
+				}
+			}
+			b.WriteString("$")
+			re, err := regexp.Compile(b.String())
+			if err != nil {
+				return nil, fmt.Errorf("pattern %q: %w", one, err)
+			}
+			out = append(out, re)
+		}
+	}
+	return out, nil
+}
+
+// ErrNothing is a sync that found no file to read.
+var ErrNothing = errors.New("no files to read under these paths")

internal/kb/kbsync/sync_test.go

@@ -0,0 +1,272 @@
+package kbsync
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+// fakeGateway holds one collection in memory and embeds by counting letters.
+type fakeGateway struct {
+	mu        sync.Mutex
+	writable  bool
+	docs      map[string]RemoteDoc
+	puts      int
+	embedded  int
+	busyFirst bool
+}
+
+func (g *fakeGateway) serve(t *testing.T) *Client {
+	t.Helper()
+	mux := http.NewServeMux()
+	coll := Collection{ID: "kb_x", Name: "ik", EmbedModel: "emb", Dims: 3}
+	mux.HandleFunc("GET /v1/kb/collections/{id}/manifest", func(w http.ResponseWriter, r *http.Request) {
+		g.mu.Lock()
+		defer g.mu.Unlock()
+		if r.PathValue("id") != "ik" && r.PathValue("id") != "kb_x" {
+			http.Error(w, `{"error":{"message":"no collection"}}`, http.StatusNotFound)
+			return
+		}
+		m := Manifest{Collection: coll}
+		m.Collection.Writable = g.writable
+		for _, d := range g.docs {
+			m.Documents = append(m.Documents, d)
+		}
+		_ = json.NewEncoder(w).Encode(m)
+	})
+	mux.HandleFunc("PUT /v1/kb/collections/{id}/documents", func(w http.ResponseWriter, r *http.Request) {
+		var d DocOut
+		_ = json.NewDecoder(r.Body).Decode(&d)
+		g.mu.Lock()
+		defer g.mu.Unlock()
+		g.puts++
+		g.docs[d.Name] = RemoteDoc{Name: d.Name, Digest: d.Digest, Chunks: len(d.Chunks)}
+		_, _ = w.Write([]byte(`{"changed":true}`))
+	})
+	mux.HandleFunc("DELETE /v1/kb/collections/{id}/documents", func(w http.ResponseWriter, r *http.Request) {
+		g.mu.Lock()
+		defer g.mu.Unlock()
+		delete(g.docs, r.URL.Query().Get("name"))
+		_, _ = w.Write([]byte(`{}`))
+	})
+	mux.HandleFunc("POST /v1/embeddings", func(w http.ResponseWriter, r *http.Request) {
+		g.mu.Lock()
+		busy := g.busyFirst
+		g.busyFirst = false
+		g.mu.Unlock()
+		if busy {
+			w.Header().Set("Retry-After", "1")
+			http.Error(w, `{"error":{"message":"the model is loading"}}`, http.StatusServiceUnavailable)
+			return
+		}
+		var in struct {
+			Input []string `json:"input"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&in)
+		type row struct {
+			Index     int       `json:"index"`
+			Embedding []float32 `json:"embedding"`
+		}
+		var out struct {
+			Data []row `json:"data"`
+		}
+		for i, s := range in.Input {
+			out.Data = append(out.Data, row{i, []float32{float32(len(s)), 1, 0}})
+		}
+		g.mu.Lock()
+		g.embedded += len(in.Input)
+		g.mu.Unlock()
+		_ = json.NewEncoder(w).Encode(out)
+	})
+	srv := httptest.NewServer(mux)
+	t.Cleanup(srv.Close)
+	h, _ := NewHTTP("")
+	return &Client{Base: srv.URL, Key: "k", HTTP: h}
+}
+
+func setup(t *testing.T) (*fakeGateway, *Client, *Ledger, string) {
+	t.Helper()
+	g := &fakeGateway{writable: true, docs: map[string]RemoteDoc{}}
+	c := g.serve(t)
+	l, err := OpenLedger(context.Background(), filepath.Join(t.TempDir(), "ledger.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = l.Close() })
+	dir := t.TempDir()
+	write(t, dir, "politika/izin.md", "# İzin\n\nYirmi gün.\n")
+	write(t, dir, "politika/masraf.txt", "Masraflar finansa.\n")
+	write(t, dir, "eski.doc", "\xd0\xcf\x11\xe0\x00binary")
+	write(t, dir, "resim.bin", "\x00\x01")
+	write(t, dir, ".git/config", "[core]")
+	write(t, dir, "politika/~$izin.docx", "lock")
+	return g, c, l, dir
+}
+
+func write(t *testing.T, dir, name, s string) {
+	t.Helper()
+	p := filepath.Join(dir, filepath.FromSlash(name))
+	if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(p, []byte(s), 0o644); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func kinds(events []Event) map[string][]string {
+	out := map[string][]string{}
+	for _, e := range events {
+		out[e.Kind] = append(out[e.Kind], e.Name)
+	}
+	return out
+}
+
+func run(t *testing.T, c *Client, l *Ledger, o Options) (Report, map[string][]string) {
+	t.Helper()
+	var mu sync.Mutex
+	var ev []Event
+	rep, err := Sync(context.Background(), c, l, o, func(e Event) {
+		mu.Lock()
+		ev = append(ev, e)
+		mu.Unlock()
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return rep, kinds(ev)
+}
+
+func TestASecondRunSendsNothingAndReadsNothing(t *testing.T) {
+	g, c, l, dir := setup(t)
+	rep, k := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}})
+	if rep.Sent != 2 || len(g.docs) != 2 {
+		t.Fatalf("first run %+v %v", rep, k)
+	}
+	if _, ok := g.docs["politika/izin.md"]; !ok {
+		t.Errorf("documents %v", g.docs)
+	}
+	// The legacy Word file is skipped with the reason, and no hidden,
+	// lock or unknown file is touched.
+	if len(k["skipped"]) != 1 || k["skipped"][0] != "eski.doc" {
+		t.Errorf("skipped %v", k["skipped"])
+	}
+
+	puts, embedded := g.puts, g.embedded
+	rep, k = run(t, c, l, Options{Collection: "ik", Roots: []string{dir}})
+	if rep.Sent != 0 || rep.Unchanged != 2 || g.puts != puts || g.embedded != embedded {
+		t.Errorf("second run %+v %v", rep, k)
+	}
+	if rep.Skipped != 1 {
+		t.Errorf("the skipped file was not reported as before: %+v", rep)
+	}
+	es, _ := l.Entries(context.Background(), c.Base, "kb_x")
+	if len(es) != 3 {
+		t.Errorf("ledger %+v", es)
+	}
+	runs, _ := l.Runs(context.Background(), 10)
+	if len(runs) != 2 || runs[0].Unchanged != 2 {
+		t.Errorf("runs %+v", runs)
+	}
+}
+
+func TestAChangedFileIsSentAgain(t *testing.T) {
+	g, c, l, dir := setup(t)
+	run(t, c, l, Options{Collection: "ik", Roots: []string{dir}})
+	old := g.docs["politika/izin.md"].Digest
+	write(t, dir, "politika/izin.md", "# İzin\n\nOtuz gün.\n")
+	// A changed time is what makes it look again; some filesystems keep
+	// seconds only.
+	later := time.Now().Add(2 * time.Second)
+	_ = os.Chtimes(filepath.Join(dir, "politika", "izin.md"), later, later)
+	rep, k := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}})
+	if rep.Sent != 1 || k["sent"][0] != "politika/izin.md" || g.docs["politika/izin.md"].Digest == old {
+		t.Errorf("after a change %+v %v", rep, k)
+	}
+}
+
+func TestDeleteRemovesOnlyWhatThisMachineSentUnderTheseRoots(t *testing.T) {
+	g, c, l, dir := setup(t)
+	run(t, c, l, Options{Collection: "ik", Roots: []string{dir}})
+	// Somebody else's document, sent from another machine.
+	g.docs["baska/makine.md"] = RemoteDoc{Name: "baska/makine.md", Digest: "x"}
+	// A file of this machine from another folder.
+	other := t.TempDir()
+	write(t, other, "not.md", "başka klasör")
+	run(t, c, l, Options{Collection: "ik", Roots: []string{other}})
+
+	if err := os.Remove(filepath.Join(dir, "politika", "masraf.txt")); err != nil {
+		t.Fatal(err)
+	}
+	rep, k := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}, Delete: true})
+	if rep.Deleted != 1 || k["deleted"][0] != "politika/masraf.txt" {
+		t.Errorf("deleted %+v %v", rep, k)
+	}
+	for _, keep := range []string{"baska/makine.md", "not.md", "politika/izin.md"} {
+		if _, ok := g.docs[keep]; !ok {
+			t.Errorf("%s was deleted", keep)
+		}
+	}
+}
+
+func TestADryRunSendsAndRecordsNothing(t *testing.T) {
+	g, c, l, dir := setup(t)
+	rep, k := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}, DryRun: true})
+	if rep.Sent != 2 || len(k["would-send"]) != 2 || rep.Bytes == 0 || rep.Chunks != 2 {
+		t.Errorf("dry run %+v %v", rep, k)
+	}
+	if g.puts != 0 || g.embedded != 0 {
+		t.Errorf("a dry run sent %d documents, embedded %d chunks", g.puts, g.embedded)
+	}
+	if es, _ := l.Entries(context.Background(), c.Base, "kb_x"); len(es) != 0 {
+		t.Errorf("a dry run wrote the ledger: %+v", es)
+	}
+}
+
+func TestAReadOnlyCollectionIsRefusedAndALoadingModelWaitedFor(t *testing.T) {
+	g, c, l, dir := setup(t)
+	g.writable = false
+	if _, err := Sync(context.Background(), c, l, Options{Collection: "ik", Roots: []string{dir}}, nil); err == nil ||
+		!strings.Contains(err.Error(), "not add") {
+		t.Errorf("read-only gave %v", err)
+	}
+	g.writable, g.busyFirst = true, true
+	var waited []string
+	c.Waiting = func(why string, _ time.Duration) { waited = append(waited, why) }
+	rep, _ := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}, Workers: 1})
+	if rep.Sent != 2 || len(waited) != 1 || !strings.Contains(waited[0], "loading") {
+		t.Errorf("after a 503 %+v, waited %v", rep, waited)
+	}
+	if _, err := Sync(context.Background(), c, l, Options{Collection: "yok", Roots: []string{dir}}, nil); err == nil {
+		t.Error("a collection that is not there was synced")
+	}
+}
+
+func TestFiltersAndNames(t *testing.T) {
+	_, c, l, dir := setup(t)
+	write(t, dir, "rapor/2026/ocak.md", "ocak")
+	write(t, dir, "rapor/taslak.md", "taslak")
+	rep, k := run(t, c, l, Options{Collection: "ik", Roots: []string{dir}, DryRun: true,
+		Include: []string{"rapor/**/*.md"}, Exclude: []string{"taslak*"}})
+	if rep.Sent != 1 || k["would-send"][0] != "rapor/2026/ocak.md" {
+		t.Errorf("filtered %+v %v", rep, k)
+	}
+	// Two roots keep their names apart.
+	other := t.TempDir()
+	write(t, other, "politika/izin.md", "aynı ad")
+	_, k = run(t, c, l, Options{Collection: "ik", Roots: []string{dir, other}, DryRun: true, Include: []string{"izin.md"}})
+	if len(k["would-send"]) != 2 || k["would-send"][0] == k["would-send"][1] {
+		t.Errorf("two roots: %v", k["would-send"])
+	}
+	if _, err := Sync(context.Background(), c, l, Options{Collection: "ik", Roots: []string{t.TempDir()}}, nil); !errors.Is(err, ErrNothing) {
+		t.Errorf("an empty folder gave %v", err)
+	}
+}

internal/pgha/pgha_test.go

@@ -159,6 +159,11 @@ func TestARunningClusterIsLeftAsItIs(t *testing.T) {
 	if !a.ranAny("CREATE ROLE") {
 		t.Error("the role was not made sure of on the leader")
 	}
+	// Enabled where the package is there, which on a running cluster is
+	// all a rerun does about it: it installs nothing.
+	if !a.ranAny("CREATE EXTENSION IF NOT EXISTS vector") {
+		t.Error("pgvector was not enabled in llmgw's database on the leader")
+	}
 }
 
 func TestTwoDatabaseMachinesWithoutAThirdVoteAreRefused(t *testing.T) {

internal/pgha/setup.go

@@ -502,6 +502,14 @@ if [ -n "$need" ]; then
   sudo DEBIAN_FRONTEND=noninteractive apt-get -qq install -y $need >/dev/null
 fi
 v=$(ls /usr/lib/postgresql | sort -n | tail -1)
+# pgvector, for knowledge bases: on every member, since any of them may lead.
+# Not a reason to stop; the store says knowledge bases are off without it.
+if [ ! -f /usr/share/postgresql/$v/extension/vector.control ]; then
+  sudo DEBIAN_FRONTEND=noninteractive apt-get -qq install -y postgresql-$v-pgvector >/dev/null 2>&1 ||
+    { sudo DEBIAN_FRONTEND=noninteractive apt-get -qq update >/dev/null 2>&1 &&
+      sudo DEBIAN_FRONTEND=noninteractive apt-get -qq install -y postgresql-$v-pgvector >/dev/null 2>&1; } ||
+    echo "no-pgvector"
+fi
 if [ -d /var/lib/postgresql/$v/main ]; then
   if sudo systemctl is-active --quiet postgresql@$v-main; then
     n=$(sudo -u postgres psql -Atc "select count(*) from pg_database where datname not in ('postgres','template0','template1')")
@@ -553,13 +561,21 @@ sudo -u postgres psql -q -v ON_ERROR_STOP=1 -v pw="$pw" <<'SQL'
 SELECT format('CREATE ROLE %I LOGIN', 'llmgw') WHERE NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = 'llmgw') \gexec
 ALTER ROLE llmgw PASSWORD :'pw';
 SELECT format('CREATE DATABASE %I OWNER %I', 'llmgw', 'llmgw') WHERE NOT EXISTS (SELECT 1 FROM pg_database WHERE datname = 'llmgw') \gexec
-SQL`, nil)
+SQL
+sudo -u postgres psql -q -d llmgw -v ON_ERROR_STOP=1 <<'SQL' || echo "pgvector-failed"
+SELECT 'CREATE EXTENSION IF NOT EXISTS vector' WHERE EXISTS (SELECT 1 FROM pg_available_extensions WHERE name = 'vector') \gexec
+SQL
+sudo -u postgres psql -d llmgw -Atc "select 'vector=' || count(*) from pg_extension where extname = 'vector'"`, nil)
 	if err != nil {
 		return fmt.Errorf("on %s: %v: %s", leader.Name, err, strings.TrimSpace(string(out)))
 	}
 	// Said as a change only when something was made: a rerun that finds
 	// both is not a reason to restart the gateway.
 	s.emit("database", !strings.Contains(string(out), "had=2"), "role and database %s on %s", Database, leader.Name)
+	if !strings.Contains(string(out), "vector=1") {
+		s.emit("pgvector", false, "pgvector is not enabled in %s, so knowledge bases stay off "+
+			"(install postgresql-<version>-pgvector on every member and run setup again)", Database)
+	}
 	return nil
 }
 

internal/router/cache.go

@@ -251,6 +251,11 @@ func reusable(req *parsedRequest, anyAnswer bool) bool {
 	if req.noStore || req.ThreadID != "" || req.ContentType != "" || !cacheEndpoints[req.Path] {
 		return false
 	}
+	// An answer from knowledge bases is the caller's own: two keys of one
+	// project can read different collections.
+	if req.knowledge || req.Header.Get(knowledgeHeader) != "" {
+		return false
+	}
 	if v := strings.ToLower(strings.TrimSpace(req.Header.Get(cacheHeader))); v == "no" || v == "off" || v == "bypass" {
 		return false
 	}

internal/router/chat.go

@@ -37,7 +37,7 @@ func (r *Router) registerChat(mux *http.ServeMux, pages *web.AccountPages) {
 		if current == "" && !r.personalOff {
 			current = personalContext
 		}
-		web.Chat(user, r.modelsFor(req, user), contexts, current, version.Version)(w, req)
+		web.Chat(user, r.modelsFor(req, user), contexts, current, version.Version, r.chatKnowledge(req, user, current))(w, req)
 	}))
 	mux.HandleFunc("POST /chat/send", pages.Guard(r.chatSend))
 	// Where a model stands while it loads, and a way to ask for it without
@@ -75,6 +75,9 @@ func (r *Router) chatSend(w http.ResponseWriter, req *http.Request, user store.U
 		// Temperature is the page's one sampling setting, held to the range
 		// every engine takes.
 		Temperature *float64 `json:"temperature"`
+		// Knowledge is a collection to answer from, "none", or "" for the
+		// default; whether it may be read is decided as for a key.
+		Knowledge string `json:"knowledge"`
 	}
 	if err := json.Unmarshal(body, &in); err != nil || in.Model == "" || len(in.Messages) == 0 {
 		http.Error(w, "a model and at least one message are required", http.StatusBadRequest)
@@ -112,6 +115,10 @@ func (r *Router) chatSend(w http.ResponseWriter, req *http.Request, user store.U
 	next.Body = io.NopCloser(bytes.NewReader(upstream))
 	next.ContentLength = int64(len(upstream))
 	next.Header.Set("Content-Type", "application/json")
+	next.Header.Del(knowledgeHeader)
+	if k := strings.TrimSpace(in.Knowledge); k != "" {
+		next.Header.Set(knowledgeHeader, k)
+	}
 
 	// The same handler the API serves, so there is exactly one request path and
 	// no second place for its rules to drift.
@@ -309,3 +316,36 @@ func (r *Router) modelsFor(req *http.Request, user store.User) []web.ChatModel {
 	})
 	return out
 }
+
+// chatKnowledge is the collections the page offers in a context, and the
+// default that answers when none is chosen.
+func (r *Router) chatKnowledge(req *http.Request, user store.User, context string) web.ChatKnowledge {
+	var out web.ChatKnowledge
+	if r.store == nil || r.store.KnowledgeAvailable() != nil {
+		return out
+	}
+	p, err := r.principalFor(req, user, context)
+	if err != nil {
+		return out
+	}
+	e := store.Effective{KeyID: p.KeyID, UserID: p.UserID, ProjectID: p.ProjectID, TeamID: p.TeamID, OrgID: p.OrgID}
+	cs, err := r.store.CollectionsFor(req.Context(), e, false)
+	if err != nil {
+		return out
+	}
+	names := map[string]string{}
+	for _, c := range cs {
+		out.Collections = append(out.Collections, web.ChatCollection{ID: c.ID, Label: c.Name})
+		names[c.ID] = c.Name
+	}
+	if def, err := r.store.KBDefaultFor(req.Context(), e); err == nil {
+		var shown []string
+		for _, id := range def {
+			if n, ok := names[id]; ok {
+				shown = append(shown, n)
+			}
+		}
+		out.Default = strings.Join(shown, ", ")
+	}
+	return out
+}

internal/router/chat_models_test.go

@@ -2,6 +2,7 @@ package router
 
 import (
 	"encoding/json"
+	"net/http"
 	"net/http/httptest"
 	"path/filepath"
 	"strings"
@@ -207,3 +208,31 @@ func TestAChatTurnCarriesItsTemperatureAndAsksForUsage(t *testing.T) {
 		t.Errorf("sent %s", raw)
 	}
 }
+
+func TestTheChatPageAsksForTheDocumentsChosenAndOnlyThose(t *testing.T) {
+	// The picker's choice becomes the header; a header the page sent itself
+	// is not trusted. On SQLite, asking is enough to tell: it is refused as
+	// knowledge bases being off, before the model is asked.
+	e := newFakeEngine(t, "qwen2.5-coder-7b-instruct")
+	rt, user := chatRouter(t, e.srv.URL)
+	waitForEndpoint(t, rt)
+	send := func(knowledge, spoofed string) *httptest.ResponseRecorder {
+		body := `{"model":"qwen2.5-coder-7b-instruct","knowledge":"` + knowledge + `","messages":[{"role":"user","content":"hi"}]}`
+		req := httptest.NewRequest("POST", "/chat/send", strings.NewReader(body))
+		if spoofed != "" {
+			req.Header.Set(knowledgeHeader, spoofed)
+		}
+		rec := httptest.NewRecorder()
+		rt.chatSend(rec, req, user)
+		return rec
+	}
+	if rec := send("politikalar", ""); rec.Code != http.StatusNotImplemented || !strings.Contains(rec.Body.String(), "SQLite") {
+		t.Errorf("a collection chosen: %d %s", rec.Code, rec.Body.String())
+	}
+	if rec := send("", "politikalar"); rec.Code != http.StatusOK {
+		t.Errorf("a header the page set itself was used: %d %s", rec.Code, rec.Body.String())
+	}
+	if rec := send("none", ""); rec.Code != http.StatusOK {
+		t.Errorf("none: %d %s", rec.Code, rec.Body.String())
+	}
+}

internal/router/handlers.go

@@ -121,6 +121,8 @@ func (r *Router) Handler() http.Handler {
 	mux.HandleFunc("GET /v1/batches", r.handleListBatches)
 	mux.HandleFunc("GET /v1/batches/{id}", r.handleGetBatch)
 	mux.HandleFunc("POST /v1/batches/{id}/cancel", r.handleCancelBatch)
+	// Knowledge bases: documents a person's llmgw-kb read and embedded.
+	r.registerKB(mux)
 	// Liveness: this process is up. It says nothing about whether it can
 	// serve, which is why it is not the thing to put a load balancer on.
 	mux.HandleFunc("GET /health", func(w http.ResponseWriter, _ *http.Request) {
@@ -245,6 +247,9 @@ func (r *Router) Handler() http.Handler {
 		if r.store != nil && r.guardLibrary != nil {
 			pages.RegisterAdminGuard(mux, r.store, r.guardLibrary)
 		}
+		if r.store != nil && r.settingsCheck != nil {
+			pages.RegisterAdminSettings(mux, r.store, r.settingsCheck, r.settingsLocal)
+		}
 		pages.Register(mux)
 		// The docs portal, with the menu of whoever is signed in, and only to
 		// them when the site asked for that.
@@ -405,6 +410,11 @@ type parsedRequest struct {
 	reservation accounting.Reservation
 	// guardIn is what the guard decided about the request.
 	guardIn guard.Verdict
+	// knowledge is set when passages from knowledge bases were added.
+	knowledge bool
+	// kbOrg is the organization whose passages were added, for the prefix
+	// cache's salt.
+	kbOrg string
 	// noStore is a policy that keeps nothing of this request.
 	noStore bool
 	// inCluster is a project whose requests may not leave the cluster.
@@ -573,6 +583,13 @@ func (r *Router) handleInference(path string) http.HandlerFunc {
 			w.Header().Set(trimmedHeader, strconv.Itoa(dropped))
 		}
 
+		// The passages a question asked knowledge bases for, before it is
+		// judged: they are text the model reads, and a document can carry
+		// instructions aimed at its reader.
+		if !r.retrieve(req.Context(), w, parsed, start) {
+			return
+		}
+
 		// Judged as it will be sent: authorised, within its limits, and with
 		// its stored conversation in it, which is text the model reads too.
 		if r.guard != nil && !r.guardInput(req.Context(), w, parsed, start) {

internal/router/kb.go

@@ -0,0 +1,355 @@
+package router
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/text/unicode/norm"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/auth"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/guard"
+	storepkg "gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+// Knowledge bases on the client listener (BACKLOG F2): what llmgw-kb, run by
+// a person on their own machine with their own key, reads and writes. The
+// documents are read, cut and embedded there; what arrives here is a
+// document's name, digest and chunks with their vectors.
+//
+// Which collections a caller may see is decided from the key's place in the
+// tree and nothing the request says, beyond naming a project for a personal
+// key. A collection the caller may not read is answered exactly as one that
+// does not exist.
+
+// projectHeader names the project a personal key acts in; the person must be
+// a member of it.
+const projectHeader = "X-Llmgw-Project"
+
+// Bounds on one document, so one request cannot hold the control plane's
+// memory or a transaction for long.
+const (
+	kbMaxBody       = 64 << 20
+	kbMaxChunks     = 20000
+	kbMaxChunkRunes = 8000
+	kbMaxNameRunes  = 1024
+)
+
+// KBCollectionView is a collection as a caller sees it.
+type KBCollectionView struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+	// Owner is the owning scope as scope:ID; OwnerName how people know it,
+	// "Acme / hr".
+	Owner      string `json:"owner"`
+	OwnerName  string `json:"owner_name,omitempty"`
+	EmbedModel string `json:"embed_model"`
+	Dims       int    `json:"dims"`
+	// Writable is whether this caller may add and remove documents.
+	Writable bool `json:"writable"`
+}
+
+// KBDocumentView is a document as the manifest lists it.
+type KBDocumentView struct {
+	Name    string    `json:"name"`
+	Digest  string    `json:"digest"`
+	Bytes   int64     `json:"bytes"`
+	Chunks  int       `json:"chunks"`
+	AddedAt time.Time `json:"added_at"`
+}
+
+// KBManifest is a collection and its documents: what a sync compares the
+// files on disk with.
+type KBManifest struct {
+	Collection KBCollectionView `json:"collection"`
+	Documents  []KBDocumentView `json:"documents"`
+}
+
+// KBPutDocument is one document, read and embedded by the client.
+type KBPutDocument struct {
+	Name   string `json:"name"`
+	Digest string `json:"digest"`
+	Bytes  int64  `json:"bytes"`
+	Chunks []struct {
+		Text      string    `json:"text"`
+		Embedding []float32 `json:"embedding"`
+	} `json:"chunks"`
+}
+
+// KBPutResult is what adding a document did.
+type KBPutResult struct {
+	Name    string `json:"name"`
+	Chunks  int    `json:"chunks"`
+	Changed bool   `json:"changed"`
+}
+
+func (r *Router) registerKB(mux *http.ServeMux) {
+	mux.HandleFunc("GET /v1/kb/collections", r.handleKBCollections)
+	mux.HandleFunc("GET /v1/kb/collections/{id}/manifest", r.handleKBManifest)
+	mux.HandleFunc("PUT /v1/kb/collections/{id}/documents", r.handleKBPut)
+	mux.HandleFunc("DELETE /v1/kb/collections/{id}/documents", r.handleKBDelete)
+}
+
+// kbCaller is the caller's place in the tree, for deciding what it may read.
+// A personal key has none unless it names a project it is a member of.
+func (r *Router) kbCaller(w http.ResponseWriter, req *http.Request) (auth.Principal, storepkg.Effective, bool) {
+	p, ok := auth.FromContext(req.Context())
+	if !ok || r.store == nil {
+		writeError(w, http.StatusNotImplemented, "invalid_request_error",
+			"knowledge bases need authentication and the store, which this gateway runs without")
+		return p, storepkg.Effective{}, false
+	}
+	if err := r.store.KnowledgeAvailable(); err != nil {
+		writeError(w, http.StatusNotImplemented, "invalid_request_error", err.Error())
+		return p, storepkg.Effective{}, false
+	}
+	e, err := r.kbEffective(req.Context(), p, req.Header.Get(projectHeader))
+	if err != nil {
+		var ke *kbError
+		if errors.As(err, &ke) {
+			writeError(w, ke.status, ke.kind, ke.msg)
+		} else {
+			writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		}
+		return p, e, false
+	}
+	return p, e, true
+}
+
+func (r *Router) kbView(ctx context.Context, c storepkg.KBCollection, writable bool) KBCollectionView {
+	return KBCollectionView{ID: c.ID, Name: c.Name, Owner: string(c.OwnerScope) + ":" + c.OwnerID,
+		OwnerName: r.store.OwnerName(ctx, c.OwnerScope, c.OwnerID), EmbedModel: c.EmbedModel, Dims: c.Dims, Writable: writable}
+}
+
+// kbCollection finds a collection by id or name among those the caller may
+// read (or write), answering 404 for one it may not.
+func (r *Router) kbCollection(w http.ResponseWriter, req *http.Request, e storepkg.Effective, write bool) (storepkg.KBCollection, bool) {
+	want := req.PathValue("id")
+	cs, err := r.store.CollectionsFor(req.Context(), e, write)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return storepkg.KBCollection{}, false
+	}
+	for _, c := range cs {
+		if c.ID == want {
+			return c, true
+		}
+	}
+	for _, c := range cs {
+		if c.Name == want {
+			return c, true
+		}
+	}
+	msg := "no collection " + want
+	if e.OrgID == "" {
+		msg += " (a personal key names its project in " + projectHeader + ")"
+	}
+	writeError(w, http.StatusNotFound, "not_found_error", msg)
+	return storepkg.KBCollection{}, false
+}
+
+func (r *Router) handleKBCollections(w http.ResponseWriter, req *http.Request) {
+	_, e, ok := r.kbCaller(w, req)
+	if !ok {
+		return
+	}
+	read, err := r.store.CollectionsFor(req.Context(), e, false)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return
+	}
+	write, err := r.store.CollectionsFor(req.Context(), e, true)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return
+	}
+	writable := map[string]bool{}
+	for _, c := range write {
+		writable[c.ID] = true
+	}
+	out := []KBCollectionView{}
+	for _, c := range read {
+		out = append(out, r.kbView(req.Context(), c, writable[c.ID]))
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"object": "list", "data": out})
+}
+
+func (r *Router) handleKBManifest(w http.ResponseWriter, req *http.Request) {
+	_, e, ok := r.kbCaller(w, req)
+	if !ok {
+		return
+	}
+	c, ok := r.kbCollection(w, req, e, false)
+	if !ok {
+		return
+	}
+	docs, err := r.store.Documents(req.Context(), c.ID)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return
+	}
+	writable, _ := r.store.CollectionsFor(req.Context(), e, true)
+	m := KBManifest{Collection: r.kbView(req.Context(), c, containsCollection(writable, c.ID)), Documents: []KBDocumentView{}}
+	for _, d := range docs {
+		m.Documents = append(m.Documents, KBDocumentView{Name: d.Name, Digest: d.Digest, Bytes: d.Bytes,
+			Chunks: d.Chunks, AddedAt: d.AddedAt})
+	}
+	writeJSON(w, http.StatusOK, m)
+}
+
+func containsCollection(cs []storepkg.KBCollection, id string) bool {
+	for _, c := range cs {
+		if c.ID == id {
+			return true
+		}
+	}
+	return false
+}
+
+// kbWriter is a caller about to change a collection: one it may write, and a
+// caller whose policy does not forbid keeping what it sends.
+func (r *Router) kbWriter(w http.ResponseWriter, req *http.Request) (auth.Principal, storepkg.KBCollection, bool) {
+	p, e, ok := r.kbCaller(w, req)
+	if !ok {
+		return p, storepkg.KBCollection{}, false
+	}
+	if r.noStore(guard.Subject{KeyID: p.KeyID, UserID: p.UserID, ProjectID: e.ProjectID,
+		TeamID: e.TeamID, OrgID: e.OrgID, Path: req.URL.Path}) {
+		writeError(w, http.StatusForbidden, "permission_error",
+			"the gateway's policy for this caller keeps nothing, and a knowledge base is documents kept")
+		return p, storepkg.KBCollection{}, false
+	}
+	c, ok := r.kbCollection(w, req, e, true)
+	return p, c, ok
+}
+
+// validDocName checks a document's name: what the client sends is a path
+// relative to what it synced, with forward slashes.
+func validDocName(n string) (string, error) {
+	if !utf8.ValidString(n) {
+		return "", errors.New("the name is not UTF-8")
+	}
+	n = norm.NFC.String(strings.TrimSpace(n))
+	switch {
+	case n == "":
+		return "", errors.New("a document needs a name")
+	case utf8.RuneCountInString(n) > kbMaxNameRunes:
+		return "", fmt.Errorf("a name has at most %d characters", kbMaxNameRunes)
+	case strings.ContainsFunc(n, unicode.IsControl):
+		return "", errors.New("the name holds a control character")
+	}
+	return n, nil
+}
+
+func (r *Router) handleKBPut(w http.ResponseWriter, req *http.Request) {
+	p, c, ok := r.kbWriter(w, req)
+	if !ok {
+		return
+	}
+	var in KBPutDocument
+	dec := json.NewDecoder(http.MaxBytesReader(w, req.Body, kbMaxBody))
+	if err := dec.Decode(&in); err != nil {
+		var tooBig *http.MaxBytesError
+		if errors.As(err, &tooBig) {
+			writeError(w, http.StatusRequestEntityTooLarge, "invalid_request_error",
+				fmt.Sprintf("a document is at most %d MiB of JSON; split the file", kbMaxBody>>20))
+			return
+		}
+		writeError(w, http.StatusBadRequest, "invalid_request_error", "the request is not valid JSON: "+err.Error())
+		return
+	}
+	name, err := validDocName(in.Name)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid_request_error", err.Error())
+		return
+	}
+	switch {
+	case in.Digest == "":
+		writeError(w, http.StatusBadRequest, "invalid_request_error", "a document needs the digest of its file")
+		return
+	case len(in.Chunks) == 0:
+		writeError(w, http.StatusBadRequest, "invalid_request_error", "a document needs at least one chunk")
+		return
+	case len(in.Chunks) > kbMaxChunks:
+		writeError(w, http.StatusBadRequest, "invalid_request_error",
+			fmt.Sprintf("%d chunks: a document has at most %d", len(in.Chunks), kbMaxChunks))
+		return
+	}
+	chunks := make([]storepkg.KBChunk, len(in.Chunks))
+	for i, ch := range in.Chunks {
+		if !utf8.ValidString(ch.Text) || strings.TrimSpace(ch.Text) == "" {
+			writeError(w, http.StatusBadRequest, "invalid_request_error", fmt.Sprintf("chunk %d has no UTF-8 text", i))
+			return
+		}
+		if utf8.RuneCountInString(ch.Text) > kbMaxChunkRunes {
+			writeError(w, http.StatusBadRequest, "invalid_request_error",
+				fmt.Sprintf("chunk %d is over %d characters", i, kbMaxChunkRunes))
+			return
+		}
+		if len(ch.Embedding) != c.Dims {
+			writeError(w, http.StatusBadRequest, "invalid_request_error",
+				fmt.Sprintf("chunk %d has %d dimensions; collection %s is embedded by %s in %d", i,
+					len(ch.Embedding), c.Name, c.EmbedModel, c.Dims))
+			return
+		}
+		chunks[i] = storepkg.KBChunk{Body: strings.ToValidUTF8(ch.Text, ""), Embedding: ch.Embedding}
+	}
+	d, changed, err := r.store.PutDocument(req.Context(), c, storepkg.KBDocument{Name: name, Digest: in.Digest,
+		Bytes: in.Bytes, AddedBy: kbActor(p)}, chunks)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return
+	}
+	if changed {
+		r.kbAudit(req.Context(), p, "PUT /v1/kb/collections/{id}/documents", c, name, http.StatusOK)
+	}
+	writeJSON(w, http.StatusOK, KBPutResult{Name: name, Chunks: d.Chunks, Changed: changed})
+}
+
+func (r *Router) handleKBDelete(w http.ResponseWriter, req *http.Request) {
+	p, c, ok := r.kbWriter(w, req)
+	if !ok {
+		return
+	}
+	name, err := validDocName(req.URL.Query().Get("name"))
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid_request_error", err.Error())
+		return
+	}
+	gone, err := r.store.DeleteDocument(req.Context(), c.ID, name)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "server_error", err.Error())
+		return
+	}
+	if !gone {
+		writeError(w, http.StatusNotFound, "not_found_error", "no document "+name+" in "+c.Name)
+		return
+	}
+	r.kbAudit(req.Context(), p, "DELETE /v1/kb/collections/{id}/documents", c, name, http.StatusOK)
+	writeJSON(w, http.StatusOK, map[string]any{"name": name, "deleted": true})
+}
+
+// kbActor is who changed a collection, as the audit log names people: the
+// person, or the key when it belongs to no one.
+func kbActor(p auth.Principal) string {
+	if p.UserID != "" {
+		return "user:" + p.UserID
+	}
+	return "key:" + p.KeyID
+}
+
+// kbAudit records a change to a collection. The document's name is kept; its
+// text never is.
+func (r *Router) kbAudit(ctx context.Context, p auth.Principal, action string, c storepkg.KBCollection, doc string, status int) {
+	err := r.store.WriteAudit(context.WithoutCancel(ctx), storepkg.AuditEvent{Actor: kbActor(p), Source: "gateway",
+		Action: action, Target: "collection:" + c.ID, Detail: c.Name + ": " + doc, Status: status})
+	if err != nil {
+		r.log.Warn("could not record a knowledge base change in the audit log", "collection", c.ID, "err", err)
+	}
+}

internal/router/kb_e2e_test.go

@@ -0,0 +1,68 @@
+package router
+
+import (
+	"context"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/kbsync"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+// The whole way: llmgw-kb's sync against this gateway, embeddings served by
+// an engine through the ordinary path, chunks in PostgreSQL, found again by
+// a search.
+func TestASyncFromAMachineIsSearchable(t *testing.T) {
+	rt := kbRouter(t)
+	ctx := t.Context()
+	s := rt.store
+	sfx := strings.ToLower(store.NewID(""))
+	org, _ := s.CreateOrg(ctx, "e2e-"+sfx)
+	team, _ := s.CreateTeam(ctx, org, "t")
+	proj, _ := s.CreateProject(ctx, team, "p")
+	coll, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: proj,
+		Name: "belgeler", EmbedModel: "qwen2.5-14b-instruct", Dims: 3})
+	if err != nil {
+		t.Fatal(err)
+	}
+	srv := httptest.NewServer(rt.Handler())
+	t.Cleanup(srv.Close)
+	h, _ := kbsync.NewHTTP("")
+	c := &kbsync.Client{Base: srv.URL, Key: kbKey(t, s, proj, ""), HTTP: h}
+
+	dir := t.TempDir()
+	for name, body := range map[string]string{
+		"izin.md":   "# Yıllık izin\n\nÇalışanlar yılda yirmi gün ücretli izin kullanır.\n",
+		"masraf.md": "# Masraflar\n\nMasraflar finans ekibine iletilir.\n",
+	} {
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(body), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	l, err := kbsync.OpenLedger(ctx, filepath.Join(t.TempDir(), "ledger.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+	rep, err := kbsync.Sync(ctx, c, l, kbsync.Options{Collection: "belgeler", Roots: []string{dir}}, nil)
+	if err != nil || rep.Sent != 2 {
+		t.Fatalf("sync: %+v %v", rep, err)
+	}
+	docs, _ := s.Documents(ctx, coll.ID)
+	if len(docs) != 2 {
+		t.Fatalf("documents %+v", docs)
+	}
+	hits, err := s.SearchChunks(context.Background(), store.KBSearch{OrgID: org, Collections: []store.KBCollection{coll},
+		Text: "kaç gün izin", K: 1})
+	if err != nil || len(hits) != 1 || hits[0].Document != "izin.md" || !strings.Contains(hits[0].Body, "Yıllık izin\n\n") {
+		t.Errorf("search: %+v %v", hits, err)
+	}
+	// Again: nothing sent.
+	rep, err = kbsync.Sync(ctx, c, l, kbsync.Options{Collection: "belgeler", Roots: []string{dir}}, nil)
+	if err != nil || rep.Sent != 0 || rep.Unchanged != 2 {
+		t.Errorf("second sync: %+v %v", rep, err)
+	}
+}

internal/router/kb_test.go

@@ -0,0 +1,208 @@
+package router
+
+import (
+	"crypto/sha256"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/config"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+func TestKnowledgeBasesSayWhyTheyAreOffOnSQLite(t *testing.T) {
+	e := newFakeEngine(t, "qwen2.5-14b-instruct")
+	rt, secret := pricedRouter(t, e.srv.URL)
+	code, _, body := call(t, rt.Handler(), secret, http.MethodGet, "/v1/kb/collections", nil)
+	if code != http.StatusNotImplemented || !strings.Contains(body, "SQLite") {
+		t.Errorf("got %d %s", code, body)
+	}
+}
+
+// kbRouter is a router on the PostgreSQL test database, with pgvector.
+func kbRouter(t *testing.T) *Router {
+	t.Helper()
+	return kbRouterWith(t, newFakeEngine(t, "qwen2.5-14b-instruct").srv.URL)
+}
+
+// kbRouterWith is a router on the PostgreSQL test database, with pgvector,
+// in front of an engine at engineURL.
+func kbRouterWith(t *testing.T, engineURL string) *Router {
+	t.Helper()
+	dsn := os.Getenv("LLMGW_TEST_POSTGRES")
+	if dsn == "" {
+		t.Skip("set LLMGW_TEST_POSTGRES to a pgvector database to run these")
+	}
+	if u, err := url.Parse(dsn); err != nil || !strings.Contains(u.Path, "test") {
+		t.Fatalf("refusing a database whose name does not say test: %s", dsn)
+	}
+	cfg := baseConfig(config.Endpoint{ID: "a", URL: engineURL, Models: []string{"qwen2.5-14b-instruct"}})
+	cfg.Auth.Enabled = true
+	cfg.Auth.Store = dsn
+	rt := newTestRouter(t, cfg)
+	if err := rt.store.KnowledgeAvailable(); err != nil {
+		t.Skipf("no pgvector in the test database: %v", err)
+	}
+	return rt
+}
+
+// kbKey makes a key in a project, or a person's key with no project.
+func kbKey(t *testing.T, s *store.DB, project, user string) string {
+	t.Helper()
+	secret := store.KeyPrefix + strings.ToLower(store.NewID("")) + strings.Repeat("k", 27)
+	sum := sha256.Sum256([]byte(secret))
+	k := store.Key{ID: store.NewID("key-"), Hash: sum[:], Prefix: secret[:8], Name: "t", ProjectID: project, CreatedAt: time.Now()}
+	var err error
+	if user != "" {
+		err = s.CreateUserKey(t.Context(), user, k)
+	} else {
+		err = s.CreateKey(t.Context(), k)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	return secret
+}
+
+func vec(x ...float32) []float32 { return x }
+
+func doc(name, digest string, embeddings ...[]float32) map[string]any {
+	var chunks []map[string]any
+	for i, e := range embeddings {
+		chunks = append(chunks, map[string]any{"text": name + " parça " + string(rune('a'+i)), "embedding": e})
+	}
+	return map[string]any{"name": name, "digest": digest, "bytes": 10, "chunks": chunks}
+}
+
+func TestKnowledgeBasesKeepTenantsApart(t *testing.T) {
+	rt := kbRouter(t)
+	h := rt.Handler()
+	ctx := t.Context()
+	s := rt.store
+	// Unique names: the test database is shared and not emptied here.
+	sfx := strings.ToLower(store.NewID(""))
+	orgA, _ := s.CreateOrg(ctx, "a-"+sfx)
+	teamA, _ := s.CreateTeam(ctx, orgA, "t")
+	hr, _ := s.CreateProject(ctx, teamA, "hr")
+	sales, _ := s.CreateProject(ctx, teamA, "sales")
+	orgB, _ := s.CreateOrg(ctx, "b-"+sfx)
+	teamB, _ := s.CreateTeam(ctx, orgB, "t")
+	other, _ := s.CreateProject(ctx, teamB, "x")
+	c, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: hr,
+		Name: "politikalar", EmbedModel: "emb", Dims: 3})
+	if err != nil {
+		t.Fatal(err)
+	}
+	hrKey, salesKey, otherKey := kbKey(t, s, hr, ""), kbKey(t, s, sales, ""), kbKey(t, s, other, "")
+	base := "/v1/kb/collections/"
+
+	// The owner's project writes, by name or by id.
+	code, out, body := call(t, h, hrKey, http.MethodPut, base+"politikalar/documents", doc("izin.pdf", "d1", vec(1, 0, 0), vec(0, 1, 0)))
+	if code != http.StatusOK || out["changed"] != true || out["chunks"] != float64(2) {
+		t.Fatalf("owner's put: %d %s", code, body)
+	}
+	code, out, _ = call(t, h, hrKey, http.MethodPut, base+c.ID+"/documents", doc("izin.pdf", "d1", vec(1, 0, 0)))
+	if code != http.StatusOK || out["changed"] != false {
+		t.Errorf("the same digest again: %d %v", code, out)
+	}
+	code, _, body = call(t, h, hrKey, http.MethodGet, base+"politikalar/manifest", nil)
+	if code != http.StatusOK || !strings.Contains(body, `"digest":"d1"`) || !strings.Contains(body, `"writable":true`) {
+		t.Errorf("manifest: %d %s", code, body)
+	}
+
+	// Another organization, and another project without a grant, see no
+	// such collection — not a refusal that says it exists.
+	for name, key := range map[string]string{"other org": otherKey, "other project": salesKey} {
+		for _, m := range []string{http.MethodGet + " manifest", http.MethodPut + " documents"} {
+			method, path, _ := strings.Cut(m, " ")
+			code, _, body := call(t, h, key, method, base+c.ID+"/"+path, doc("x", "y", vec(1, 0, 0)))
+			if code != http.StatusNotFound {
+				t.Errorf("%s %s: %d %s", name, m, code, body)
+			}
+		}
+	}
+
+	// A read grant lets sales read, not write.
+	if err := s.Grant(ctx, store.KBGrant{Scope: store.ScopeProject, ScopeID: sales, Collection: c.ID, Perm: store.KBRead}); err != nil {
+		t.Fatal(err)
+	}
+	if code, _, body := call(t, h, salesKey, http.MethodGet, base+"politikalar/manifest", nil); code != http.StatusOK ||
+		!strings.Contains(body, `"writable":false`) {
+		t.Errorf("read grant, manifest: %d %s", code, body)
+	}
+	if code, _, _ := call(t, h, salesKey, http.MethodPut, base+"politikalar/documents", doc("x", "y", vec(1, 0, 0))); code != http.StatusNotFound {
+		t.Errorf("read grant, put: %d", code)
+	}
+	if code, _, body := call(t, h, salesKey, http.MethodGet, "/v1/kb/collections", nil); code != http.StatusOK ||
+		!strings.Contains(body, "politikalar") || !strings.Contains(body, `"owner_name":"a-`+sfx+` / t / hr"`) {
+		t.Errorf("read grant, list: %d %s", code, body)
+	}
+	if _, _, body := call(t, h, otherKey, http.MethodGet, "/v1/kb/collections", nil); strings.Contains(body, "politikalar") {
+		t.Errorf("another organization lists it: %s", body)
+	}
+
+	// Vectors of the wrong size are refused before anything is written.
+	if code, _, body := call(t, h, hrKey, http.MethodPut, base+"politikalar/documents", doc("b.md", "d", vec(1, 0))); code != http.StatusBadRequest ||
+		!strings.Contains(body, "dimensions") {
+		t.Errorf("wrong dimensions: %d %s", code, body)
+	}
+
+	if code, _, body := call(t, h, hrKey, http.MethodDelete, base+"politikalar/documents?name=izin.pdf", nil); code != http.StatusOK {
+		t.Errorf("delete: %d %s", code, body)
+	}
+	if code, _, _ := call(t, h, hrKey, http.MethodDelete, base+"politikalar/documents?name=izin.pdf", nil); code != http.StatusNotFound {
+		t.Errorf("deleting again: %d", code)
+	}
+}
+
+func TestAPersonalKeyReadsOnlyInTheProjectItNames(t *testing.T) {
+	rt := kbRouter(t)
+	h := rt.Handler()
+	ctx := t.Context()
+	s := rt.store
+	sfx := strings.ToLower(store.NewID(""))
+	org, _ := s.CreateOrg(ctx, "p-"+sfx)
+	team, _ := s.CreateTeam(ctx, org, "t")
+	hr, _ := s.CreateProject(ctx, team, "hr")
+	fin, _ := s.CreateProject(ctx, team, "fin")
+	uid := store.NewID("u-")
+	if err := s.CreateUser(ctx, store.User{ID: uid, Email: uid + "@example.com", Name: "u", PasswordHash: "x",
+		State: store.UserActive, CreatedAt: time.Now()}); err != nil {
+		t.Fatal(err)
+	}
+	if err := s.AddMembership(ctx, uid, store.ScopeProject, hr, "member", "t", time.Now()); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: hr,
+		Name: "ik", EmbedModel: "emb", Dims: 3}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: fin,
+		Name: "finans", EmbedModel: "emb", Dims: 3}); err != nil {
+		t.Fatal(err)
+	}
+	key := kbKey(t, s, "", uid)
+	get := func(project string) (int, string) {
+		req, _ := http.NewRequest(http.MethodGet, "/v1/kb/collections", nil)
+		req.Header.Set("Authorization", "Bearer "+key)
+		if project != "" {
+			req.Header.Set(projectHeader, project)
+		}
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, req)
+		return rec.Code, rec.Body.String()
+	}
+	if code, body := get(""); code != http.StatusOK || strings.Contains(body, "ik") {
+		t.Errorf("no project named: %d %s", code, body)
+	}
+	if code, body := get(hr); code != http.StatusOK || !strings.Contains(body, `"ik"`) || strings.Contains(body, "finans") {
+		t.Errorf("in hr: %d %s", code, body)
+	}
+	if code, _ := get(fin); code != http.StatusForbidden {
+		t.Errorf("a project the person is not in: %d", code)
+	}
+}

internal/router/metrics.go

@@ -45,8 +45,12 @@ type metrics struct {
 	// cacheRequests counts what the answer cache did, cacheBytes and
 	// cacheEntries what it holds.
 	cacheRequests *prometheus.CounterVec
-	cacheBytes    prometheus.Gauge
-	cacheEntries  prometheus.Gauge
+	// kbRetrievals counts requests answered from knowledge bases by what
+	// the search found; kbRetrieval is how long finding it took.
+	kbRetrievals *prometheus.CounterVec
+	kbRetrieval  prometheus.Histogram
+	cacheBytes   prometheus.Gauge
+	cacheEntries prometheus.Gauge
 
 	tenant *tenantMetrics
 	guard  *guardMetrics
@@ -138,6 +142,16 @@ func newMetrics() *metrics {
 				"hit (answered from it), miss (asked the model, and kept the answer if it could), " +
 				"bypass (not one whose answer is reused).",
 		}, []string{"model", "result"}),
+		kbRetrievals: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "llmgw_kb_retrievals_total",
+			Help: "Chat requests that named knowledge-base collections, by what came of it: " +
+				"found (passages given to the model), nothing (none matched), refused (not answered).",
+		}, []string{"result"}),
+		kbRetrieval: prometheus.NewHistogram(prometheus.HistogramOpts{
+			Name:    "llmgw_kb_retrieval_seconds",
+			Help:    "Time to find a request's passages: the question embedded, and the collections searched.",
+			Buckets: []float64{0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10},
+		}),
 		cacheBytes: prometheus.NewGauge(prometheus.GaugeOpts{
 			Name: "llmgw_cache_bytes",
 			Help: "Memory the answers kept for reuse take in this process, roughly.",
@@ -161,6 +175,7 @@ func (m *metrics) collectors() []prometheus.Collector {
 		m.adapterAffinity, m.adapterLoads, m.adapterEvictions,
 		m.kvDecisions, m.kvTokenize,
 		m.cacheRequests, m.cacheBytes, m.cacheEntries,
+		m.kbRetrievals, m.kbRetrieval,
 	}, slices.Concat(m.tenant.collectors(), m.guard.collectors(), m.token.collectors())...)
 }
 

internal/router/rag.go

@@ -0,0 +1,446 @@
+package router
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/auth"
+	storepkg "gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+// Answering from knowledge bases (BACKLOG F3): a chat request that names
+// collections in X-Llmgw-Knowledge has the passages its last question needs
+// found in them and put in front of the model, with their sources, before it
+// is judged and sent. Which collections it may name is decided by the key's
+// place in the tree, exactly as llmgw-kb's own requests are; one it may not
+// read is answered as one that does not exist.
+
+const (
+	// knowledgeHeader names the collections, by name or id, comma separated.
+	knowledgeHeader = "X-Llmgw-Knowledge"
+	// knowledgeKHeader is how many passages; kbDefaultK when absent.
+	knowledgeKHeader = "X-Llmgw-Knowledge-K"
+	// sourcesHeader answers which passages were given: document#chunk, each
+	// path-escaped, in the order they were numbered.
+	sourcesHeader = "x-llmgw-sources"
+
+	kbDefaultK = 5
+	kbMaxK     = 20
+)
+
+// kbContextIntro is what the model is told about the passages. In English,
+// which every model reads; it is asked to answer in the question's language.
+const kbContextIntro = "Below are passages from the organisation's own documents, found for the user's last " +
+	"question. Answer from them, and cite the ones you use as [1], [2] and so on. If they do not hold the " +
+	"answer, say so rather than guessing. Answer in the language of the question."
+
+const kbNothingFound = "The user asked a question meant to be answered from the organisation's documents, " +
+	"and nothing in them matched it. Say so, rather than answering from general knowledge as if it were " +
+	"the organisation's."
+
+// kbEffective is a caller's place in the tree for reading collections: a
+// personal key has one only in a project it names and belongs to.
+func (r *Router) kbEffective(ctx context.Context, p auth.Principal, project string) (storepkg.Effective, error) {
+	e := storepkg.Effective{KeyID: p.KeyID, UserID: p.UserID, ProjectID: p.ProjectID, TeamID: p.TeamID, OrgID: p.OrgID}
+	project = strings.TrimSpace(project)
+	if project == "" || p.ProjectID != "" || p.UserID == "" {
+		return e, nil
+	}
+	may, err := r.store.CanUseProject(ctx, p.UserID, project)
+	if err != nil {
+		return e, err
+	}
+	if !may {
+		return e, &kbError{status: http.StatusForbidden, kind: "permission_error", msg: "you are not a member of project " + project}
+	}
+	eff, err := r.store.ResolveFor(ctx, p.KeyID, p.UserID, project)
+	if err != nil {
+		return e, err
+	}
+	e.ProjectID, e.TeamID, e.OrgID = eff.ProjectID, eff.TeamID, eff.OrgID
+	return e, nil
+}
+
+// kbError is a refusal with the status and kind a client is answered with.
+type kbError struct {
+	status     int
+	kind, msg  string
+	retryAfter string
+}
+
+func (e *kbError) Error() string { return e.msg }
+
+// retrieve finds and adds the passages a request asked for. It answers false
+// when it has answered the client itself.
+func (r *Router) retrieve(ctx context.Context, w http.ResponseWriter, req *parsedRequest, start time.Time) bool {
+	names := splitList(req.Header.Get(knowledgeHeader))
+	if len(names) == 1 && strings.EqualFold(names[0], "none") {
+		// Asked for no passages, whatever the default.
+		return true
+	}
+	// Without the header, the default of the caller's part of the tree, if
+	// it has one. A default is the administrator's choice, not the
+	// caller's, so it never refuses a request: a collection the caller
+	// cannot read is left out, and a search that fails is answered without
+	// passages.
+	explicit := len(names) > 0
+	if !explicit {
+		if req.Path != "/v1/chat/completions" || req.internal || r.store == nil || r.store.KnowledgeAvailable() != nil {
+			return true
+		}
+		p, ok := auth.FromContext(ctx)
+		if !ok {
+			return true
+		}
+		if names = r.kbDefaults(ctx, p, req.Header.Get(projectHeader)); len(names) == 0 {
+			return true
+		}
+	}
+	fail := func(err error) bool {
+		if !explicit {
+			r.log.Warn("a knowledge-base default could not be searched; answering without it", "model", req.Model, "err", err)
+			r.m.kbRetrievals.WithLabelValues("skipped").Inc()
+			return true
+		}
+		var ke *kbError
+		if !errors.As(err, &ke) {
+			ke = &kbError{status: http.StatusInternalServerError, kind: "server_error", msg: err.Error()}
+		}
+		if ke.retryAfter != "" {
+			w.Header().Set("Retry-After", ke.retryAfter)
+		}
+		writeError(w, ke.status, ke.kind, ke.msg)
+		r.m.kbRetrievals.WithLabelValues("refused").Inc()
+		r.m.observeRequest(r.metricModel(req.Model), "", ke.status, time.Since(start), nil, 0)
+		return false
+	}
+	if req.Path != "/v1/chat/completions" {
+		return fail(&kbError{status: http.StatusBadRequest, kind: "invalid_request_error",
+			msg: knowledgeHeader + " is for chat completions"})
+	}
+	p, ok := auth.FromContext(ctx)
+	if !ok || r.store == nil {
+		return fail(&kbError{status: http.StatusNotImplemented, kind: "invalid_request_error",
+			msg: "knowledge bases need authentication and the store, which this gateway runs without"})
+	}
+	if err := r.store.KnowledgeAvailable(); err != nil {
+		return fail(&kbError{status: http.StatusNotImplemented, kind: "invalid_request_error", msg: err.Error()})
+	}
+	k := kbDefaultK
+	if v := req.Header.Get(knowledgeKHeader); v != "" {
+		n, err := strconv.Atoi(v)
+		if err != nil || n < 1 || n > kbMaxK {
+			return fail(&kbError{status: http.StatusBadRequest, kind: "invalid_request_error",
+				msg: fmt.Sprintf("%s is 1 to %d", knowledgeKHeader, kbMaxK)})
+		}
+		k = n
+	}
+	began := time.Now()
+	e, err := r.kbEffective(ctx, p, req.Header.Get(projectHeader))
+	if err != nil {
+		return fail(err)
+	}
+	allowed, err := r.store.CollectionsFor(ctx, e, false)
+	if err != nil {
+		return fail(err)
+	}
+	var colls []storepkg.KBCollection
+	for _, n := range names {
+		c, ok := pickCollection(allowed, n)
+		if !ok && !explicit {
+			continue
+		}
+		if !ok {
+			msg := "no collection " + n
+			if e.OrgID == "" {
+				msg += " (a personal key names its project in " + projectHeader + ")"
+			}
+			return fail(&kbError{status: http.StatusNotFound, kind: "not_found_error", msg: msg})
+		}
+		colls = append(colls, c)
+	}
+	if len(colls) == 0 {
+		return true
+	}
+
+	question := lastUserText(req.UpstreamBody)
+	if strings.TrimSpace(question) == "" && !explicit {
+		return true
+	}
+	if strings.TrimSpace(question) == "" {
+		return fail(&kbError{status: http.StatusBadRequest, kind: "invalid_request_error",
+			msg: knowledgeHeader + " needs a last user message with text to search for"})
+	}
+	embeddings := map[string][]float32{}
+	for _, c := range colls {
+		if _, done := embeddings[c.EmbedModel]; done {
+			continue
+		}
+		v, err := r.embedFor(ctx, p, c.EmbedModel, question)
+		if err != nil {
+			return fail(err)
+		}
+		embeddings[c.EmbedModel] = v
+	}
+	hits, err := r.store.SearchChunks(ctx, storepkg.KBSearch{OrgID: e.OrgID, Collections: colls,
+		Embeddings: embeddings, Text: question, K: k})
+	if err != nil {
+		return fail(err)
+	}
+
+	// What fits: the context the model has, less what the request already
+	// holds and the answer it asked room for — the last passages go first.
+	room := -1
+	if _, entry := r.resolve(req.Model); entry.ContextLength > 0 {
+		room = (entry.ContextLength-req.MaxTokens)*4 - len(req.UpstreamBody) - len(kbContextIntro) - 64
+	}
+	var b strings.Builder
+	var sources []string
+	for i, h := range hits {
+		block := fmt.Sprintf("\n\n[%d] %s\n%s", i+1, h.Document, strings.TrimSpace(h.Body))
+		if room >= 0 && b.Len()+len(block) > room {
+			break
+		}
+		b.WriteString(block)
+		sources = append(sources, url.PathEscape(h.Document)+"#"+strconv.Itoa(h.Ord))
+	}
+	text := kbNothingFound
+	if len(sources) > 0 {
+		text = kbContextIntro + b.String()
+	}
+	body, err := withSystemText(req.UpstreamBody, text)
+	if err != nil {
+		return fail(&kbError{status: http.StatusBadRequest, kind: "invalid_request_error", msg: err.Error()})
+	}
+	req.UpstreamBody = body
+	req.PromptTokens = len(body) / 4
+	req.knowledge = true
+	req.kbOrg = e.OrgID
+	// Set now: the proxy writes the headers when the answer starts.
+	w.Header().Set(sourcesHeader, strings.Join(sources, ","))
+	result := "found"
+	if len(sources) == 0 {
+		result = "nothing"
+	}
+	r.m.kbRetrievals.WithLabelValues(result).Inc()
+	r.m.kbRetrieval.Observe(time.Since(began).Seconds())
+	return true
+}
+
+// pickCollection finds a collection by id, then by name.
+func pickCollection(cs []storepkg.KBCollection, want string) (storepkg.KBCollection, bool) {
+	for _, c := range cs {
+		if c.ID == want {
+			return c, true
+		}
+	}
+	for _, c := range cs {
+		if strings.EqualFold(c.Name, want) {
+			return c, true
+		}
+	}
+	return storepkg.KBCollection{}, false
+}
+
+func splitList(v string) []string {
+	var out []string
+	seen := map[string]bool{}
+	for _, s := range strings.Split(v, ",") {
+		if s = strings.TrimSpace(s); s != "" && !seen[s] {
+			seen[s] = true
+			out = append(out, s)
+		}
+	}
+	return out
+}
+
+// embedFor has a model embed the question as the caller: through the
+// ordinary path, so the caller's limits, budget and guardrails apply to it
+// and it is counted to them.
+func (r *Router) embedFor(ctx context.Context, p auth.Principal, model, text string) ([]float32, error) {
+	body, _ := json.Marshal(map[string]any{"model": model, "input": []string{text}})
+	hreq, err := http.NewRequestWithContext(auth.WithPrincipal(ctx, p), http.MethodPost, "/v1/embeddings", bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	hreq.Header.Set("Content-Type", "application/json")
+	w := &bufferWriter{header: http.Header{}}
+	r.handleInference("/v1/embeddings")(w, hreq)
+	status := w.status
+	if status == 0 {
+		status = http.StatusOK
+	}
+	if status != http.StatusOK {
+		msg := errorMessageOf(w.buf.Bytes())
+		ke := &kbError{status: status, kind: "server_error",
+			msg:        fmt.Sprintf("the knowledge base's model %s could not embed the question: %s", model, msg),
+			retryAfter: w.header.Get("Retry-After")}
+		if status < 500 {
+			ke.kind = "invalid_request_error"
+		}
+		return nil, ke
+	}
+	var res struct {
+		Data []struct {
+			Embedding []float32 `json:"embedding"`
+		} `json:"data"`
+	}
+	if err := json.Unmarshal(w.buf.Bytes(), &res); err != nil || len(res.Data) != 1 {
+		return nil, fmt.Errorf("%s answered no embedding", model)
+	}
+	return res.Data[0].Embedding, nil
+}
+
+func errorMessageOf(b []byte) string {
+	var e struct {
+		Error struct {
+			Message string `json:"message"`
+		} `json:"error"`
+	}
+	if json.Unmarshal(b, &e) == nil && e.Error.Message != "" {
+		return e.Error.Message
+	}
+	return strings.TrimSpace(string(b))
+}
+
+// lastUserText is the text of a chat request's last user message: its
+// content, or the text parts of it.
+func lastUserText(body []byte) string {
+	var in struct {
+		Messages []struct {
+			Role    string          `json:"role"`
+			Content json.RawMessage `json:"content"`
+		} `json:"messages"`
+	}
+	if json.Unmarshal(body, &in) != nil {
+		return ""
+	}
+	for i := len(in.Messages) - 1; i >= 0; i-- {
+		m := in.Messages[i]
+		if m.Role != "user" {
+			continue
+		}
+		var s string
+		if json.Unmarshal(m.Content, &s) == nil {
+			return s
+		}
+		var parts []struct {
+			Type string `json:"type"`
+			Text string `json:"text"`
+		}
+		if json.Unmarshal(m.Content, &parts) == nil {
+			var b strings.Builder
+			for _, p := range parts {
+				if p.Type == "text" {
+					b.WriteString(p.Text + "\n")
+				}
+			}
+			return b.String()
+		}
+		return ""
+	}
+	return ""
+}
+
+// withSystemText adds text to a chat request's system message: appended to
+// the first one when it leads, or as a new one at the start. One system
+// message, first, because some models' templates refuse anything else.
+func withSystemText(body []byte, text string) ([]byte, error) {
+	var top map[string]json.RawMessage
+	if err := json.Unmarshal(body, &top); err != nil {
+		return nil, fmt.Errorf("the body is not a JSON object: %w", err)
+	}
+	var msgs []map[string]json.RawMessage
+	if err := json.Unmarshal(top["messages"], &msgs); err != nil {
+		return nil, errors.New("the request has no messages")
+	}
+	added := false
+	if len(msgs) > 0 {
+		var role string
+		_ = json.Unmarshal(msgs[0]["role"], &role)
+		if role == "system" || role == "developer" {
+			var s string
+			if json.Unmarshal(msgs[0]["content"], &s) == nil {
+				msgs[0]["content"], _ = json.Marshal(strings.TrimRight(s, "\n") + "\n\n" + text)
+				added = true
+			} else {
+				var parts []json.RawMessage
+				if json.Unmarshal(msgs[0]["content"], &parts) == nil {
+					part, _ := json.Marshal(map[string]string{"type": "text", "text": "\n\n" + text})
+					msgs[0]["content"], _ = json.Marshal(append(parts, part))
+					added = true
+				}
+			}
+		}
+	}
+	if !added {
+		content, _ := json.Marshal(text)
+		role, _ := json.Marshal("system")
+		msgs = append([]map[string]json.RawMessage{{"role": role, "content": content}}, msgs...)
+	}
+	var err error
+	if top["messages"], err = json.Marshal(msgs); err != nil {
+		return nil, err
+	}
+	return json.Marshal(top)
+}
+
+// kbDefaultTTL is how long a caller's default is remembered: a change to one
+// is in force within it, and a chat request does not cost a query.
+const kbDefaultTTL = 30 * time.Second
+
+type kbDefaultEntry struct {
+	at    time.Time
+	names []string
+}
+
+// kbDefaults is the default collections in force for a caller.
+func (r *Router) kbDefaults(ctx context.Context, p auth.Principal, project string) []string {
+	key := p.KeyID + "|" + p.ProjectID + "|" + project
+	r.kbDefMu.Lock()
+	e, ok := r.kbDefCache[key]
+	r.kbDefMu.Unlock()
+	if ok && time.Since(e.at) < kbDefaultTTL {
+		return e.names
+	}
+	var names []string
+	if eff, err := r.kbEffective(ctx, p, project); err == nil {
+		names, err = r.store.KBDefaultFor(ctx, eff)
+		if err != nil {
+			r.log.Warn("could not read the knowledge-base defaults", "err", err)
+		}
+	}
+	r.kbDefMu.Lock()
+	if r.kbDefCache == nil || len(r.kbDefCache) > 10000 {
+		r.kbDefCache = map[string]kbDefaultEntry{}
+	}
+	r.kbDefCache[key] = kbDefaultEntry{at: time.Now(), names: names}
+	r.kbDefMu.Unlock()
+	return names
+}
+
+// withCacheSalt sets vLLM's cache_salt to one derived from an organization:
+// the same for its requests, so they still share a cache among themselves.
+func withCacheSalt(body []byte, org string) []byte {
+	var top map[string]json.RawMessage
+	if json.Unmarshal(body, &top) != nil {
+		return body
+	}
+	sum := sha256.Sum256([]byte("llmgw-kb\x00" + org))
+	top["cache_salt"], _ = json.Marshal(hex.EncodeToString(sum[:16]))
+	out, err := json.Marshal(top)
+	if err != nil {
+		return body
+	}
+	return out
+}

internal/router/rag_test.go

@@ -0,0 +1,255 @@
+package router
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/config"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/kb/kbsync"
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+func TestPassagesJoinTheLeadingSystemMessage(t *testing.T) {
+	type msg struct {
+		Role    string `json:"role"`
+		Content any    `json:"content"`
+	}
+	read := func(b []byte) []msg {
+		var in struct {
+			Messages []msg `json:"messages"`
+			Model    string
+		}
+		if err := json.Unmarshal(b, &in); err != nil {
+			t.Fatal(err)
+		}
+		return in.Messages
+	}
+	// None: one is put first.
+	out, err := withSystemText([]byte(`{"model":"m","messages":[{"role":"user","content":"q"}],"temperature":0.1}`), "CTX")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m := read(out); len(m) != 2 || m[0].Role != "system" || m[0].Content != "CTX" || !strings.Contains(string(out), `"temperature":0.1`) {
+		t.Errorf("no system message: %s", out)
+	}
+	// One leading: added to it, never a second.
+	out, _ = withSystemText([]byte(`{"messages":[{"role":"system","content":"Be brief."},{"role":"user","content":"q"}]}`), "CTX")
+	if m := read(out); len(m) != 2 || m[0].Content != "Be brief.\n\nCTX" {
+		t.Errorf("leading system message: %s", out)
+	}
+	// Parts: a text part added.
+	out, _ = withSystemText([]byte(`{"messages":[{"role":"system","content":[{"type":"text","text":"Be brief."}]},{"role":"user","content":"q"}]}`), "CTX")
+	if !strings.Contains(string(out), `{"text":"\n\nCTX","type":"text"}`) {
+		t.Errorf("parts: %s", out)
+	}
+	if _, err := withSystemText([]byte(`{"prompt":"x"}`), "CTX"); err == nil {
+		t.Error("a request without messages was changed")
+	}
+}
+
+func TestTheCacheSaltIsAnOrganizations(t *testing.T) {
+	body := []byte(`{"model":"m","messages":[],"temperature":0}`)
+	a1, a2, b := withCacheSalt(body, "org-a"), withCacheSalt(body, "org-a"), withCacheSalt(body, "org-b")
+	var x, y struct {
+		Salt string  `json:"cache_salt"`
+		T    float64 `json:"temperature"`
+	}
+	_ = json.Unmarshal(a1, &x)
+	_ = json.Unmarshal(b, &y)
+	if string(a1) != string(a2) || x.Salt == "" || x.Salt == y.Salt || len(x.Salt) != 32 || !strings.Contains(string(a1), `"temperature":0`) {
+		t.Errorf("salts %s / %s", a1, b)
+	}
+}
+
+func TestTheLastUserMessageIsTheQuestion(t *testing.T) {
+	body := `{"messages":[{"role":"user","content":"first"},{"role":"assistant","content":"a"},
+		{"role":"user","content":[{"type":"text","text":"yıllık izin"},{"type":"image_url","image_url":{"url":"x"}}]}]}`
+	if got := lastUserText([]byte(body)); strings.TrimSpace(got) != "yıllık izin" {
+		t.Errorf("question %q", got)
+	}
+}
+
+func TestKnowledgeOnSQLiteSaysWhy(t *testing.T) {
+	e := newFakeEngine(t, "qwen2.5-14b-instruct")
+	rt, secret := pricedRouter(t, e.srv.URL)
+	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions",
+		strings.NewReader(`{"model":"q14","messages":[{"role":"user","content":"hi"}]}`))
+	req.Header.Set("Authorization", "Bearer "+secret)
+	req.Header.Set(knowledgeHeader, "docs")
+	rec := httptest.NewRecorder()
+	rt.Handler().ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotImplemented || !strings.Contains(rec.Body.String(), "SQLite") || e.calls.Load() != 0 {
+		t.Errorf("got %d %s, engine asked %d times", rec.Code, rec.Body.String(), e.calls.Load())
+	}
+}
+
+func TestAChatIsAnsweredFromItsCollections(t *testing.T) {
+	dsn := os.Getenv("LLMGW_TEST_POSTGRES")
+	if dsn == "" {
+		t.Skip("set LLMGW_TEST_POSTGRES to a pgvector database to run this")
+	}
+	e := newFakeEngine(t, "qwen2.5-14b-instruct")
+	rt := kbRouterWith(t, e.srv.URL)
+	ctx := t.Context()
+	s := rt.store
+	sfx := strings.ToLower(store.NewID(""))
+	org, _ := s.CreateOrg(ctx, "rag-"+sfx)
+	team, _ := s.CreateTeam(ctx, org, "t")
+	proj, _ := s.CreateProject(ctx, team, "p")
+	other, _ := s.CreateOrg(ctx, "other-"+sfx)
+	oteam, _ := s.CreateTeam(ctx, other, "t")
+	oproj, _ := s.CreateProject(ctx, oteam, "p")
+	if _, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: proj,
+		Name: "politika-" + sfx, EmbedModel: "qwen2.5-14b-instruct", Dims: 3}); err != nil {
+		t.Fatal(err)
+	}
+	key, otherKey := kbKey(t, s, proj, ""), kbKey(t, s, oproj, "")
+	srv := httptest.NewServer(rt.Handler())
+	t.Cleanup(srv.Close)
+
+	dir := t.TempDir()
+	_ = os.WriteFile(filepath.Join(dir, "izin.md"), []byte("# Yıllık izin\n\nÇalışanlar yılda yirmi gün izin kullanır.\n"), 0o644)
+	_ = os.WriteFile(filepath.Join(dir, "masraf.md"), []byte("# Masraf\n\nFişler ayın beşine kadar verilir.\n"), 0o644)
+	h, _ := kbsync.NewHTTP("")
+	l, _ := kbsync.OpenLedger(ctx, filepath.Join(t.TempDir(), "l.db"))
+	defer l.Close()
+	if rep, err := kbsync.Sync(ctx, &kbsync.Client{Base: srv.URL, Key: key, HTTP: h}, l,
+		kbsync.Options{Collection: "politika-" + sfx, Roots: []string{dir}}, nil); err != nil || rep.Sent != 2 {
+		t.Fatalf("sync %+v %v", rep, err)
+	}
+
+	chat := func(key, collections string) *http.Response {
+		t.Helper()
+		req, _ := http.NewRequest(http.MethodPost, srv.URL+"/v1/chat/completions", strings.NewReader(
+			`{"model":"qwen2.5-14b-instruct","messages":[{"role":"system","content":"Kısa yaz."},{"role":"user","content":"kaç gün yıllık izin var"}]}`))
+		req.Header.Set("Authorization", "Bearer "+key)
+		if collections != "" {
+			req.Header.Set(knowledgeHeader, collections)
+		}
+		req.Header.Set(knowledgeKHeader, "1")
+		res, err := http.DefaultClient.Do(req)
+		if err != nil {
+			t.Fatal(err)
+		}
+		res.Body.Close()
+		return res
+	}
+	res := chat(key, "politika-"+sfx)
+	if res.StatusCode != http.StatusOK || res.Header.Get(sourcesHeader) != "izin.md#0" {
+		t.Fatalf("answered %d, sources %q", res.StatusCode, res.Header.Get(sourcesHeader))
+	}
+	sent, _ := e.last.Load().([]byte)
+	var body struct {
+		Messages []struct {
+			Role, Content string
+		}
+	}
+	_ = json.Unmarshal(sent, &body)
+	if len(body.Messages) != 2 || body.Messages[0].Role != "system" ||
+		!strings.HasPrefix(body.Messages[0].Content, "Kısa yaz.\n\nBelow are passages") ||
+		!strings.Contains(body.Messages[0].Content, "[1] izin.md\nYıllık izin\n\nÇalışanlar yılda yirmi gün") ||
+		strings.Contains(body.Messages[0].Content, "Fişler") {
+		t.Errorf("the model was sent:\n%s", sent)
+	}
+
+	// The engine here is no vLLM: no salt is sent to it.
+	if strings.Contains(string(sent), "cache_salt") {
+		t.Errorf("a salt was sent to an engine that is not vLLM:\n%s", sent)
+	}
+
+	// A project default answers a request that names nothing, and none
+	// turns it off.
+	if err := s.SetKBDefault(ctx, store.KBDefault{Scope: store.ScopeProject, ScopeID: proj,
+		Collections: []string{mustID(t, s, "politika-"+sfx)}}); err != nil {
+		t.Fatal(err)
+	}
+	if res := chat(key, ""); res.Header.Get(sourcesHeader) != "izin.md#0" {
+		t.Errorf("by default: sources %q", res.Header.Get(sourcesHeader))
+	}
+	if res := chat(key, "none"); res.Header.Get(sourcesHeader) != "" {
+		t.Errorf("with none: sources %q", res.Header.Get(sourcesHeader))
+	}
+	sent, _ = e.last.Load().([]byte)
+	if strings.Contains(string(sent), "Below are passages") {
+		t.Errorf("none still added passages:\n%s", sent)
+	}
+
+	// Another organization's key names it: as if it did not exist, and the
+	// model is not asked.
+	calls := e.calls.Load()
+	if res := chat(otherKey, "politika-"+sfx); res.StatusCode != http.StatusNotFound || e.calls.Load() != calls {
+		t.Errorf("another organization: %d, engine asked %d more times", res.StatusCode, e.calls.Load()-calls)
+	}
+}
+
+func mustID(t *testing.T, s *store.DB, name string) string {
+	t.Helper()
+	cs, err := s.Collections(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range cs {
+		if c.Name == name {
+			return c.ID
+		}
+	}
+	t.Fatalf("no collection %s", name)
+	return ""
+}
+
+func TestAVLLMReplicaGetsTheOrganizationsSaltOnlyWithPassages(t *testing.T) {
+	dsn := os.Getenv("LLMGW_TEST_POSTGRES")
+	if dsn == "" {
+		t.Skip("set LLMGW_TEST_POSTGRES to a pgvector database to run this")
+	}
+	e := newFakeEngine(t, "qwen2.5-14b-instruct")
+	cfg := baseConfig(config.Endpoint{ID: "a", URL: e.srv.URL, Engine: "vllm", Models: []string{"qwen2.5-14b-instruct"}})
+	cfg.Auth.Enabled = true
+	cfg.Auth.Store = dsn
+	rt := newTestRouter(t, cfg)
+	if err := rt.store.KnowledgeAvailable(); err != nil {
+		t.Skip(err)
+	}
+	ctx := t.Context()
+	s := rt.store
+	sfx := strings.ToLower(store.NewID(""))
+	org, _ := s.CreateOrg(ctx, "salt-"+sfx)
+	team, _ := s.CreateTeam(ctx, org, "t")
+	proj, _ := s.CreateProject(ctx, team, "p")
+	c, err := s.CreateCollection(ctx, store.KBCollection{OwnerScope: store.ScopeProject, OwnerID: proj,
+		Name: "c-" + sfx, EmbedModel: "qwen2.5-14b-instruct", Dims: 3})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := s.PutDocument(ctx, c, store.KBDocument{Name: "a.md", Digest: "d"},
+		[]store.KBChunk{{Body: "yıllık izin yirmi gün", Embedding: []float32{1, 1, 1}}}); err != nil {
+		t.Fatal(err)
+	}
+	key := kbKey(t, s, proj, "")
+	ask := func(knowledge string) string {
+		req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(
+			`{"model":"qwen2.5-14b-instruct","messages":[{"role":"user","content":"yıllık izin"}]}`))
+		req.Header.Set("Authorization", "Bearer "+key)
+		if knowledge != "" {
+			req.Header.Set(knowledgeHeader, knowledge)
+		}
+		rec := httptest.NewRecorder()
+		rt.Handler().ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("%d %s", rec.Code, rec.Body.String())
+		}
+		b, _ := e.last.Load().([]byte)
+		return string(b)
+	}
+	if got := ask(c.Name); !strings.Contains(got, `"cache_salt":"`) {
+		t.Errorf("no salt with passages:\n%s", got)
+	}
+	if got := ask(""); strings.Contains(got, "cache_salt") {
+		t.Errorf("a salt without passages:\n%s", got)
+	}
+}

internal/router/router.go

@@ -17,6 +17,7 @@ import (
 	"net/netip"
 	"slices"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -171,6 +172,15 @@ type Router struct {
 	// none is configured, which leaves the charts off the page.
 	history    web.History
 	histWindow time.Duration
+
+	// kbDefCache remembers each caller's default knowledge-base
+	// collections for kbDefaultTTL.
+	kbDefMu    sync.Mutex
+	kbDefCache map[string]kbDefaultEntry
+
+	// settingsCheck and settingsLocal mount the portal's settings page.
+	settingsCheck func([]byte) error
+	settingsLocal []string
 }
 
 // SetClusterView gives the router the data the /admin page renders.
@@ -194,6 +204,13 @@ func (r *Router) SetGuard(g guard.Guard) { r.guard = g }
 // SetGuardLibrary is the policies the guard was built from, for the pages.
 func (r *Router) SetGuardLibrary(c func() guard.Config) { r.guardLibrary = c }
 
+// SetSettingsCheck enables the portal's settings page: check says whether a
+// document would load as the cluster's settings beside this machine's own
+// server.yaml, and local are the keys that file keeps.
+func (r *Router) SetSettingsCheck(check func([]byte) error, local []string) {
+	r.settingsCheck, r.settingsLocal = check, local
+}
+
 // SetStopped refuses, or again serves, every request for a model.
 func (r *Router) SetStopped(stopped bool) { r.stopped.Store(stopped) }
 
@@ -1073,6 +1090,14 @@ func (r *Router) dispatchOne(ctx context.Context, w http.ResponseWriter, req *pa
 		if isAdapter && !onDemand && dec.Endpoint.Engine != "vllm" {
 			body = withAdapter(body, model, ad.index, ad.scale)
 		}
+		// Passages of one organization's documents never share cached
+		// blocks with another's: a prefix found warm would say what another
+		// tenant asked about, by how fast its answer started. vLLM keys its
+		// prefix cache by this salt; other engines are not sent a field
+		// they may refuse.
+		if req.kbOrg != "" && dec.Endpoint.Engine == "vllm" && req.ContentType == "" {
+			body = withCacheSalt(body, req.kbOrg)
+		}
 		// What computes the answer, said before the proxy writes the headers.
 		// A model can have replicas on cards and on CPUs at once, and the two
 		// differ tenfold in speed: a reply that came slowly is otherwise

internal/router/router_test.go

@@ -66,6 +66,20 @@ func newFakeEngine(t *testing.T, model string) *fakeEngine {
 		w.Header().Set("Content-Type", "application/json")
 		fmt.Fprintf(w, `{"model":%q,"choices":[{"message":{"content":"hi"}}],"usage":{"prompt_tokens":4,"completion_tokens":2}}`, model)
 	})
+	// Three dimensions: the input's length in bytes, its number of words,
+	// and 1.
+	mux.HandleFunc("POST /v1/embeddings", func(w http.ResponseWriter, r *http.Request) {
+		var in struct {
+			Input []string `json:"input"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&in)
+		var rows []string
+		for i, s := range in.Input {
+			rows = append(rows, fmt.Sprintf(`{"index":%d,"embedding":[%d,%d,1]}`, i, len(s), len(strings.Fields(s))))
+		}
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintf(w, `{"model":%q,"data":[%s],"usage":{"prompt_tokens":%d}}`, model, strings.Join(rows, ","), len(in.Input))
+	})
 	f.srv = httptest.NewServer(mux)
 	t.Cleanup(f.srv.Close)
 	return f

internal/store/hierarchy.go

@@ -214,6 +214,12 @@ func (s *DB) deleteEmpty(ctx context.Context, scope Scope, id, del string, check
 				busy = append(busy, plural(n, ch.noun))
 			}
 		}
+		// Not an emptyCheck: the table is there only on PostgreSQL.
+		if n, err := s.kbOwnedBy(ctx, c, scope, id); err != nil {
+			return err
+		} else if n > 0 {
+			busy = append(busy, plural(n, "collection"))
+		}
 		if len(busy) > 0 {
 			return fmt.Errorf("%w: it still has %s", ErrNotEmpty, strings.Join(busy, " and "))
 		}
@@ -222,6 +228,9 @@ func (s *DB) deleteEmpty(ctx context.Context, scope Scope, id, del string, check
 			string(scope), string(MemberScope(scope)), id); err != nil {
 			return err
 		}
+		if err := s.kbForgetScope(ctx, c, scope, id); err != nil {
+			return err
+		}
 		res, err := c.ExecContext(ctx, del, id)
 		if err != nil {
 			return err
@@ -229,7 +238,7 @@ func (s *DB) deleteEmpty(ctx context.Context, scope Scope, id, del string, check
 		if n, _ := res.RowsAffected(); n == 0 {
 			return ErrNotFound
 		}
-		return nil
+		return s.kbDropPartition(ctx, c, scope, id)
 	})
 }
 
@@ -248,6 +257,10 @@ func (s *DB) DeleteUser(ctx context.Context, userID string, at time.Time) error
 			millis(at), userID); err != nil {
 			return err
 		}
+		// A person's own collections go with the account.
+		if err := s.kbForgetScope(ctx, c, ScopeUser, userID); err != nil {
+			return err
+		}
 		res, err := c.ExecContext(ctx, `DELETE FROM users WHERE id = ?`, userID)
 		if err != nil {
 			return err

internal/store/knowledge_test.go

@@ -0,0 +1,446 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"math"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestKnowledgeIsOffOnSQLite(t *testing.T) {
+	s := openDB(t)
+	tree(t, s)
+	err := s.KnowledgeAvailable()
+	if !errors.Is(err, ErrKnowledgeOff) || !strings.Contains(err.Error(), "SQLite") {
+		t.Fatalf("SQLite store says %v", err)
+	}
+	if _, err := s.CreateCollection(context.Background(), KBCollection{
+		OwnerScope: ScopeProject, OwnerID: "proj1", Name: "x", EmbedModel: "m", Dims: 3,
+	}); !errors.Is(err, ErrKnowledgeOff) {
+		t.Errorf("creating a collection on SQLite gave %v", err)
+	}
+	// Deleting from the tree still works without the tables.
+	if err := s.DeleteProject(context.Background(), "proj1"); err != nil {
+		t.Errorf("deleting a project on SQLite: %v", err)
+	}
+}
+
+// kbTwoOrgs is org1 (team1/proj1, team2/proj2) and org2 (team3/proj3).
+func kbTwoOrgs(t *testing.T, s *DB) {
+	t.Helper()
+	ctx := context.Background()
+	tree(t, s)
+	for _, err := range []error{
+		s.PutTeam(ctx, Team{ID: "team2", OrgID: "org1", Name: "Finance"}),
+		s.PutProject(ctx, Project{ID: "proj2", TeamID: "team2", Name: "Payroll"}),
+		s.PutOrg(ctx, Org{ID: "org2", Name: "Other"}),
+		s.PutTeam(ctx, Team{ID: "team3", OrgID: "org2", Name: "Research"}),
+		s.PutProject(ctx, Project{ID: "proj3", TeamID: "team3", Name: "Chat"}),
+	} {
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+// unit is a 3-dimensional unit vector pointing mostly along axis i.
+func unit(i int) []float32 {
+	v := []float32{0.1, 0.1, 0.1}
+	v[i] = 1
+	n := float32(math.Sqrt(float64(v[0]*v[0] + v[1]*v[1] + v[2]*v[2])))
+	for j := range v {
+		v[j] /= n
+	}
+	return v
+}
+
+func mustCollection(t *testing.T, s *DB, scope Scope, owner, org, name string) KBCollection {
+	t.Helper()
+	c, err := s.CreateCollection(context.Background(), KBCollection{
+		OwnerScope: scope, OwnerID: owner, OrgID: org, Name: name, EmbedModel: "emb", Dims: 3,
+	})
+	if err != nil {
+		t.Fatalf("creating %s: %v", name, err)
+	}
+	return c
+}
+
+func mustDoc(t *testing.T, s *DB, c KBCollection, name string, bodies ...string) {
+	t.Helper()
+	var chunks []KBChunk
+	for i, b := range bodies {
+		chunks = append(chunks, KBChunk{Body: b, Embedding: unit(i % 3)})
+	}
+	if _, _, err := s.PutDocument(context.Background(), c, KBDocument{Name: name, Digest: name + "-1", Bytes: 10}, chunks); err != nil {
+		t.Fatalf("adding %s: %v", name, err)
+	}
+}
+
+func openKB(t *testing.T) *DB {
+	t.Helper()
+	s := openPG(t)
+	if err := s.KnowledgeAvailable(); err != nil {
+		t.Skipf("the test database has no pgvector: %v", err)
+	}
+	return s
+}
+
+func names(cs []KBCollection) string {
+	var out []string
+	for _, c := range cs {
+		out = append(out, c.Name)
+	}
+	return strings.Join(out, ",")
+}
+
+func TestPostgresCollectionsReachOnlyTheirChain(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	mustCollection(t, s, ScopeOrg, "org1", "", "handbook")
+	mustCollection(t, s, ScopeTeam, "team1", "", "research")
+	pay := mustCollection(t, s, ScopeProject, "proj2", "", "payroll")
+	mustCollection(t, s, ScopeProject, "proj3", "", "other-org")
+
+	read := func(e Effective) string {
+		t.Helper()
+		got, err := s.CollectionsFor(ctx, e, false)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return names(got)
+	}
+	inProj1 := Effective{KeyID: "k1", ProjectID: "proj1", TeamID: "team1", OrgID: "org1"}
+	if got := read(inProj1); got != "handbook,research" {
+		t.Errorf("proj1 reads %q", got)
+	}
+	if got := read(Effective{KeyID: "k3", ProjectID: "proj3", TeamID: "team3", OrgID: "org2"}); got != "other-org" {
+		t.Errorf("org2 reads %q", got)
+	}
+	// A personal key with no project reads nothing, whatever its person
+	// belongs to.
+	if got := read(Effective{KeyID: "kp", UserID: "u1"}); got != "" {
+		t.Errorf("a caller outside any organization reads %q", got)
+	}
+
+	// A grant to a key adds that collection for that key alone.
+	_, k := mustKey(t, s, "k1", "proj1")
+	if err := s.Grant(ctx, KBGrant{Scope: ScopeKey, ScopeID: k.ID, Collection: pay.ID, Perm: KBRead}); err != nil {
+		t.Fatal(err)
+	}
+	if got := read(inProj1); got != "handbook,payroll,research" {
+		t.Errorf("proj1 with a key grant reads %q", got)
+	}
+	if got := read(Effective{KeyID: "k-other", ProjectID: "proj1", TeamID: "team1", OrgID: "org1"}); got != "handbook,research" {
+		t.Errorf("another key of proj1 reads %q", got)
+	}
+	// Read is not write.
+	w, err := s.CollectionsFor(ctx, inProj1, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(names(w), "payroll") {
+		t.Errorf("a read grant gave write: %s", names(w))
+	}
+}
+
+func TestPostgresGrantsNeverCrossOrganizations(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	c := mustCollection(t, s, ScopeProject, "proj1", "", "docs")
+	for _, g := range []KBGrant{
+		{Scope: ScopeOrg, ScopeID: "org2"},
+		{Scope: ScopeTeam, ScopeID: "team3"},
+		{Scope: ScopeProject, ScopeID: "proj3"},
+	} {
+		g.Collection, g.Perm = c.ID, KBRead
+		if err := s.Grant(ctx, g); err == nil || !strings.Contains(err.Error(), "another organization") {
+			t.Errorf("granting to %s %s gave %v", g.Scope, g.ScopeID, err)
+		}
+	}
+	_, k3 := mustKey(t, s, "k3", "proj3")
+	if err := s.Grant(ctx, KBGrant{Scope: ScopeKey, ScopeID: k3.ID, Collection: c.ID, Perm: KBRead}); err == nil {
+		t.Error("a key of another organization was granted a collection")
+	}
+	// A person who belongs to nothing in the organization cannot own or be
+	// granted one there.
+	if err := s.CreateUser(ctx, User{ID: "u1", Email: "u1@example.com", Name: "u", PasswordHash: "x",
+		State: UserActive, CreatedAt: time.Now()}); err != nil {
+		t.Fatal(err)
+	}
+	if err := s.Grant(ctx, KBGrant{Scope: ScopeUser, ScopeID: "u1", Collection: c.ID, Perm: KBRead}); err == nil {
+		t.Error("a person with no membership in the organization was granted a collection")
+	}
+	if err := s.AddMembership(ctx, "u1", ScopeProject, "proj2", "member", "t", time.Now()); err != nil {
+		t.Fatal(err)
+	}
+	if err := s.Grant(ctx, KBGrant{Scope: ScopeUser, ScopeID: "u1", Collection: c.ID, Perm: KBRead}); err != nil {
+		t.Errorf("a member of a project in the organization: %v", err)
+	}
+}
+
+func TestPostgresSearchReturnsOnlyAllowedChunks(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	mine := mustCollection(t, s, ScopeProject, "proj1", "", "mine")
+	secret := mustCollection(t, s, ScopeProject, "proj2", "", "secret")
+	foreign := mustCollection(t, s, ScopeProject, "proj3", "", "foreign")
+	mustDoc(t, s, mine, "a.md", "vacation policy is twenty days", "expenses go through finance")
+	mustDoc(t, s, secret, "salaries.md", "vacation salaries are confidential")
+	mustDoc(t, s, foreign, "theirs.md", "vacation at the other company")
+
+	hits, err := s.SearchChunks(ctx, KBSearch{OrgID: "org1", Collections: []KBCollection{mine},
+		Embeddings: map[string][]float32{"emb": unit(0)}, Text: "vacation policy", K: 5})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) == 0 || hits[0].Body != "vacation policy is twenty days" || hits[0].Document != "a.md" {
+		t.Fatalf("best hit %+v", hits)
+	}
+	for _, h := range hits {
+		if h.Collection != mine.ID {
+			t.Errorf("a search of %s returned a chunk of %s: %q", mine.Name, h.Collection, h.Body)
+		}
+	}
+
+	// A collection of another organization is refused, not searched.
+	if _, err := s.SearchChunks(ctx, KBSearch{OrgID: "org1", Collections: []KBCollection{mine, foreign},
+		Embeddings: map[string][]float32{"emb": unit(0)}, Text: "vacation", K: 5}); err == nil {
+		t.Error("a search across organizations was run")
+	}
+}
+
+func TestPostgresRowSecurityHoldsWithoutTheFilter(t *testing.T) {
+	// The second line: a query that forgets its WHERE gets nothing outside
+	// the scope its transaction set, and nothing at all without one.
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	mine := mustCollection(t, s, ScopeProject, "proj1", "", "mine")
+	other := mustCollection(t, s, ScopeProject, "proj2", "", "other")
+	mustDoc(t, s, mine, "a.md", "one", "two")
+	mustDoc(t, s, other, "b.md", "three")
+
+	count := func(org string, colls ...string) int {
+		t.Helper()
+		var n int
+		err := s.inTx(ctx, func(c conn) error {
+			if org != "" {
+				if err := kbScope(ctx, c, org, colls); err != nil {
+					return err
+				}
+			}
+			return c.QueryRowContext(ctx, `SELECT COUNT(*) FROM kb_chunks`).Scan(&n)
+		})
+		if err != nil {
+			t.Fatal(err)
+		}
+		return n
+	}
+	if n := count(""); n != 0 {
+		t.Errorf("with no scope set, %d chunks are visible", n)
+	}
+	if n := count("org1", mine.ID); n != 2 {
+		t.Errorf("scoped to one collection, %d chunks are visible", n)
+	}
+	if n := count("org2", mine.ID); n != 0 {
+		t.Errorf("a collection named under the wrong organization shows %d chunks", n)
+	}
+	// Nor can a write put a chunk outside its scope.
+	err := s.inTx(ctx, func(c conn) error {
+		if err := kbScope(ctx, c, "org1", []string{mine.ID}); err != nil {
+			return err
+		}
+		docs, _ := s.Documents(ctx, other.ID)
+		_, err := c.ExecContext(ctx, `INSERT INTO kb_chunks (org_id, collection, doc_id, ord, body, embedding)
+			VALUES ('org1', ?, ?, 9, 'x', '[1,0,0]')`, other.ID, docs[0].ID)
+		return err
+	})
+	if err == nil || !strings.Contains(err.Error(), "row-level security") {
+		t.Errorf("writing into another collection gave %v", err)
+	}
+}
+
+func TestPostgresDocumentsReplaceWholeAndSkipTheSame(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	c := mustCollection(t, s, ScopeProject, "proj1", "", "docs")
+	put := func(digest string, bodies ...string) bool {
+		t.Helper()
+		var chunks []KBChunk
+		for _, b := range bodies {
+			chunks = append(chunks, KBChunk{Body: b, Embedding: unit(0)})
+		}
+		_, changed, err := s.PutDocument(ctx, c, KBDocument{Name: "a.md", Digest: digest}, chunks)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return changed
+	}
+	if !put("d1", "old one", "old two") {
+		t.Error("a new document was not a change")
+	}
+	if put("d1", "ignored") {
+		t.Error("the same digest again was a change")
+	}
+	if !put("d2", "new") {
+		t.Error("a new digest was not a change")
+	}
+	hits, err := s.SearchChunks(ctx, KBSearch{OrgID: "org1", Collections: []KBCollection{c},
+		Embeddings: map[string][]float32{"emb": unit(0)}, K: 10})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 1 || hits[0].Body != "new" {
+		t.Errorf("after replacing, the collection holds %+v", hits)
+	}
+	if _, _, err := s.PutDocument(ctx, c, KBDocument{Name: "b.md", Digest: "x"},
+		[]KBChunk{{Body: "x", Embedding: []float32{1, 0}}}); err == nil {
+		t.Error("a chunk of the wrong dimension was accepted")
+	}
+}
+
+func TestPostgresScopesWithCollectionsAreNotDeleted(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	c := mustCollection(t, s, ScopeProject, "proj2", "", "docs")
+	mustDoc(t, s, c, "a.md", "x")
+	if err := s.DeleteProject(ctx, "proj2"); !errors.Is(err, ErrNotEmpty) || !strings.Contains(err.Error(), "collection") {
+		t.Errorf("deleting a project with a collection gave %v", err)
+	}
+	if err := s.DeleteCollection(ctx, c.ID); err != nil {
+		t.Fatal(err)
+	}
+	if err := s.DeleteProject(ctx, "proj2"); err != nil {
+		t.Errorf("deleting the project once its collection is gone: %v", err)
+	}
+	var n int
+	if err := s.raw.QueryRowContext(ctx, `SELECT COUNT(*) FROM pg_indexes WHERE indexname = $1`,
+		kbVectorIndex(c.ID)).Scan(&n); err != nil || n != 0 {
+		t.Errorf("the collection's index is left behind (%d, %v)", n, err)
+	}
+}
+
+func TestPostgresAPersonsCollectionsGoWithTheAccount(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	if err := s.CreateUser(ctx, User{ID: "u1", Email: "u1@example.com", Name: "u", PasswordHash: "x",
+		State: UserActive, CreatedAt: time.Now()}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.CreateCollection(ctx, KBCollection{OwnerScope: ScopeUser, OwnerID: "u1", OrgID: "org1",
+		Name: "notes", EmbedModel: "emb", Dims: 3}); err == nil {
+		t.Error("a person outside the organization made a collection in it")
+	}
+	if err := s.AddMembership(ctx, "u1", ScopeTeam, "team1", "member", "t", time.Now()); err != nil {
+		t.Fatal(err)
+	}
+	c := mustCollection(t, s, ScopeUser, "u1", "org1", "notes")
+	mustDoc(t, s, c, "n.md", "x")
+	if err := s.DeleteUser(ctx, "u1", time.Now()); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.Collection(ctx, c.ID); !errors.Is(err, ErrNotFound) {
+		t.Errorf("the person's collection outlived the account: %v", err)
+	}
+}
+
+func TestPostgresMeaningOutweighsSharedWords(t *testing.T) {
+	// The PoC's case: the question shares its everyday words with one
+	// passage and its meaning with another.
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	c := mustCollection(t, s, ScopeProject, "proj1", "", "docs")
+	put := func(name, body string, v []float32) {
+		t.Helper()
+		if _, _, err := s.PutDocument(ctx, c, KBDocument{Name: name, Digest: name}, []KBChunk{{Body: body, Embedding: v}}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	put("yillik.md", "yıllık izin kadar izin alır izin", unit(0))
+	put("babalik.md", "babalık hakkı on gündür", unit(1))
+	for _, f := range []string{"a", "b", "c"} {
+		put(f+".md", "başka bir konu", unit(2))
+	}
+	hits, err := s.SearchChunks(ctx, KBSearch{OrgID: "org1", Collections: []KBCollection{c},
+		Embeddings: map[string][]float32{"emb": unit(1)}, Text: "babalar ne kadar izin alır", K: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 1 || hits[0].Document != "babalik.md" {
+		t.Errorf("best hit %+v", hits)
+	}
+	// And a question that holds a passage's exact words still finds it,
+	// with nothing embedded at all (the model down).
+	hits, err = s.SearchChunks(ctx, KBSearch{OrgID: "org1", Collections: []KBCollection{c}, Text: "babalık hakkı", K: 1})
+	if err != nil || len(hits) != 1 || hits[0].Document != "babalik.md" || hits[0].Score != textWeight {
+		t.Errorf("text alone: %+v %v", hits, err)
+	}
+}
+
+func TestOrQueryMatchesAnyWord(t *testing.T) {
+	if got := orQuery("Yıllık izin kaç gün? İzin & 'x' -- a"); got != "Yıllık | izin | gün" {
+		t.Errorf("orQuery gave %q", got)
+	}
+	// Words every passage has are no evidence of anything.
+	if got := orQuery("Babalar NE kadar izin alır, ve İÇİN"); got != "Babalar | izin | alır" {
+		t.Errorf("stop words kept: %q", got)
+	}
+	if got := orQuery("?!"); got != "" {
+		t.Errorf("no words gave %q", got)
+	}
+}
+
+func TestPostgresDefaultsAreTheNarrowestAndStayInTheirOrganization(t *testing.T) {
+	ctx := context.Background()
+	s := openKB(t)
+	kbTwoOrgs(t, s)
+	hand := mustCollection(t, s, ScopeOrg, "org1", "", "handbook")
+	team := mustCollection(t, s, ScopeTeam, "team1", "", "research")
+	foreign := mustCollection(t, s, ScopeOrg, "org2", "", "theirs")
+	if err := s.SetKBDefault(ctx, KBDefault{Scope: ScopeProject, ScopeID: "proj1", Collections: []string{foreign.ID}}); err == nil {
+		t.Error("another organization's collection became a default")
+	}
+	for _, d := range []KBDefault{
+		{Scope: ScopeOrg, ScopeID: "org1", Collections: []string{hand.ID}},
+		{Scope: ScopeTeam, ScopeID: "team1", Collections: []string{team.ID, hand.ID}},
+	} {
+		if err := s.SetKBDefault(ctx, d); err != nil {
+			t.Fatal(err)
+		}
+	}
+	in := func(e Effective) string {
+		got, err := s.KBDefaultFor(ctx, e)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return strings.Join(got, ",")
+	}
+	if got := in(Effective{KeyID: "k", ProjectID: "proj1", TeamID: "team1", OrgID: "org1"}); got != team.ID+","+hand.ID {
+		t.Errorf("in team1: %q", got)
+	}
+	if got := in(Effective{KeyID: "k", ProjectID: "proj2", TeamID: "team2", OrgID: "org1"}); got != hand.ID {
+		t.Errorf("in team2: %q", got)
+	}
+	if got := in(Effective{KeyID: "k", ProjectID: "proj3", TeamID: "team3", OrgID: "org2"}); got != "" {
+		t.Errorf("in org2: %q", got)
+	}
+	// A collection removed leaves every default that named it.
+	if err := s.DeleteCollection(ctx, hand.ID); err != nil {
+		t.Fatal(err)
+	}
+	if got := in(Effective{KeyID: "k", ProjectID: "proj1", TeamID: "team1", OrgID: "org1"}); got != team.ID {
+		t.Errorf("after removing one: %q", got)
+	}
+	if got := in(Effective{KeyID: "k", ProjectID: "proj2", TeamID: "team2", OrgID: "org1"}); got != "" {
+		t.Errorf("a default left empty stayed: %q", got)
+	}
+}

internal/store/migrations/postgres/0035_knowledge.sql

@@ -0,0 +1,55 @@
+-- Knowledge bases: collections of a company's documents that requests are
+-- answered from (BACKLOG F). PostgreSQL only: there is no SQLite file of this
+-- number, and on SQLite the feature is off.
+--
+-- The chunks themselves are not here. They need the pgvector extension, which
+-- only a superuser can create and which a cluster may not have installed; a
+-- migration that failed for want of it would stop the control plane from
+-- starting at all. The store creates kb_chunks when it opens, if it can
+-- (knowledge.go), and says why not when it cannot.
+
+-- A collection has one owner in the tenancy tree and lives inside one
+-- organization, which no grant can cross.
+CREATE TABLE kb_collections (
+  id          TEXT PRIMARY KEY,
+  org_id      TEXT NOT NULL REFERENCES organizations(id),
+  owner_scope TEXT NOT NULL,
+  owner_id    TEXT NOT NULL,
+  name        TEXT NOT NULL,
+  -- Vectors from two models are not comparable, so a collection is embedded
+  -- by one model and its dimension is fixed with it.
+  embed_model TEXT NOT NULL,
+  dims        INTEGER NOT NULL,
+  created_at  BIGINT NOT NULL,
+  created_by  TEXT NOT NULL DEFAULT '',
+  UNIQUE (org_id, name)
+);
+CREATE INDEX kb_collections_by_owner ON kb_collections(owner_scope, owner_id);
+
+-- Who else may read or write a collection. Like guard_attachments, keyed by
+-- scope with everything below the scope included; unlike guard policies,
+-- grants add up rather than narrow.
+CREATE TABLE kb_grants (
+  scope      TEXT NOT NULL,
+  scope_id   TEXT NOT NULL,
+  collection TEXT NOT NULL REFERENCES kb_collections(id) ON DELETE CASCADE,
+  perm       TEXT NOT NULL,
+  added_at   BIGINT NOT NULL,
+  added_by   TEXT NOT NULL DEFAULT '',
+  PRIMARY KEY (scope, scope_id, collection)
+);
+CREATE INDEX kb_grants_by_collection ON kb_grants(collection);
+
+-- A document as added, by name within its collection. The digest is what
+-- decides whether adding it again changes anything.
+CREATE TABLE kb_documents (
+  id         TEXT PRIMARY KEY,
+  collection TEXT NOT NULL REFERENCES kb_collections(id) ON DELETE CASCADE,
+  name       TEXT NOT NULL,
+  digest     TEXT NOT NULL,
+  bytes      BIGINT NOT NULL,
+  chunks     INTEGER NOT NULL,
+  added_at   BIGINT NOT NULL,
+  added_by   TEXT NOT NULL DEFAULT '',
+  UNIQUE (collection, name)
+);

internal/store/migrations/postgres/0036_kb_defaults.sql

@@ -0,0 +1,12 @@
+-- The collections a part of the tree answers from when a request names
+-- none (BACKLOG F3): on an organization, team, project or key, the narrowest
+-- one that has any winning. PostgreSQL only, as the collections are.
+CREATE TABLE kb_defaults (
+  scope       TEXT NOT NULL,
+  scope_id    TEXT NOT NULL,
+  -- Collection IDs, comma separated, in the order given.
+  collections TEXT NOT NULL,
+  added_at    BIGINT NOT NULL,
+  added_by    TEXT NOT NULL DEFAULT '',
+  PRIMARY KEY (scope, scope_id)
+);

internal/store/postgres.go

@@ -55,9 +55,13 @@ func OpenPostgres(ctx context.Context, dsn string) (*DB, error) {
 		_ = db.Close()
 		return nil, err
 	}
-	return &DB{
+	s := &DB{
 		raw:     db,
 		dialect: PostgresDialect,
 		db:      bound{c: PostgresDialect, to: db},
-	}, nil
+	}
+	// Not fatal: a store without pgvector serves everything but knowledge
+	// bases, and says why when somebody asks for one.
+	s.kbErr = s.ensureKnowledge(ctx)
+	return s, nil
 }

internal/store/sqlite.go

@@ -48,6 +48,10 @@ type DB struct {
 	// personal is what a person's own use is held to when nobody wrote a
 	// limit for them; see SetPersonalDefaults.
 	personal *Limits
+
+	// kbErr is why this store cannot hold knowledge bases, nil when it can;
+	// set once at open (knowledge.go).
+	kbErr error
 }
 
 // OpenSQLite opens (creating if needed) a database and brings it up to date.

internal/web/account.go

@@ -90,7 +90,9 @@ type AccountPages struct {
 	audit audit.Sink
 	// hasGuard is set when /admin/guard is registered, and guardLibrary
 	// with it: the policies in force, whose judges the mirror page serves.
-	hasGuard     bool
+	hasGuard bool
+	// hasSettings is set when /admin/settings is registered.
+	hasSettings  bool
 	guardLibrary func() guard.Config
 	// guardFor names the guardrail policies in force for someone, and
 	// whether they keep nothing; nil when there are none.

internal/web/admin_settings.go

@@ -0,0 +1,174 @@
+package web
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+// The cluster's settings, edited in the browser (BACKLOG E4): the document
+// `llmgw ctl config edit` opens, for whoever has no terminal on a control
+// plane. The same rules hold here as there — a version is checked as a
+// control plane would load it before it is kept, it is made from the newest
+// version or refused, and every change is in force on every control plane
+// within seconds and in the audit log.
+
+// SettingsAdmin is where the cluster's settings are kept.
+type SettingsAdmin interface {
+	ClusterSettings(ctx context.Context) (store.SettingsVersion, error)
+	ClusterSettingsAt(ctx context.Context, version int64) (store.SettingsVersion, error)
+	ClusterSettingsHistory(ctx context.Context, limit int) ([]store.SettingsVersion, error)
+	PutClusterSettings(ctx context.Context, base int64, body, by, note string) (int64, error)
+}
+
+type settingsPageData struct {
+	Nav     Nav
+	Version string
+	CSRF    string
+	// Current is the version in force; Shown the one in the editor, which
+	// is an earlier one when ?version= asked for it.
+	Current, Shown store.SettingsVersion
+	Earlier        bool
+	// Body is what the editor holds: the version shown, or what was sent
+	// and refused, so a refusal does not lose the edit.
+	Body      string
+	Note      string
+	History   []settingsRow
+	LocalKeys []string
+	Notice    string
+	Error     string
+}
+
+type settingsRow struct {
+	Version  int64
+	At, By   string
+	Note     string
+	InForce  bool
+	Selected bool
+}
+
+// RegisterAdminSettings mounts /admin/settings, for administrators only:
+// the settings hold webhook addresses and the like, so even reading them is
+// not every staff role's.
+func (p *AccountPages) RegisterAdminSettings(mux *http.ServeMux, s SettingsAdmin, check func([]byte) error, localKeys []string) {
+	p.hasSettings = true
+	page := func(w http.ResponseWriter, r *http.Request, admin store.User, d settingsPageData) {
+		ctx, l := r.Context(), langOf(r)
+		d.Nav, d.Version, d.CSRF, d.LocalKeys = p.navFor(r, admin, "settings"), p.version, csrfFor(r), localKeys
+		cur, err := s.ClusterSettings(ctx)
+		if err != nil {
+			d.Error = l.Err(err)
+		}
+		d.Current = cur
+		if d.Shown.Version == 0 {
+			d.Shown = cur
+		}
+		d.Earlier = d.Shown.Version != cur.Version
+		if d.Body == "" {
+			d.Body = d.Shown.Body
+		}
+		if hist, err := s.ClusterSettingsHistory(ctx, 30); err == nil {
+			for _, v := range hist {
+				d.History = append(d.History, settingsRow{Version: v.Version, At: l.Date(v.At.UTC()) + " " + v.At.UTC().Format("15:04"),
+					By: v.By, Note: v.Note, InForce: v.Version == cur.Version, Selected: v.Version == d.Shown.Version})
+			}
+		}
+		noStore(w)
+		render(w, r, "admin_settings", d)
+	}
+	adminsOnly := func(next func(w http.ResponseWriter, r *http.Request, admin store.User)) http.HandlerFunc {
+		return p.adminOnly(func(w http.ResponseWriter, r *http.Request, admin store.User) {
+			if !admin.IsAdmin {
+				http.NotFound(w, r)
+				return
+			}
+			if r.Method == http.MethodPost {
+				sess, _, _ := p.session(r)
+				if !p.accounts.CheckCSRF(sess, r.FormValue("csrf")) {
+					http.Error(w, "bad request", http.StatusBadRequest)
+					return
+				}
+			}
+			next(w, r, admin)
+		})
+	}
+
+	mux.HandleFunc("GET /admin/settings", adminsOnly(func(w http.ResponseWriter, r *http.Request, admin store.User) {
+		var d settingsPageData
+		if q := r.URL.Query().Get("version"); q != "" {
+			n, err := strconv.ParseInt(q, 10, 64)
+			if v, verr := s.ClusterSettingsAt(r.Context(), n); err == nil && verr == nil && v.Version != 0 {
+				d.Shown = v
+			} else {
+				d.Error = langOf(r).T("settings.err.no_version")
+			}
+		}
+		page(w, r, admin, d)
+	}))
+
+	mux.HandleFunc("POST /admin/settings", adminsOnly(func(w http.ResponseWriter, r *http.Request, admin store.User) {
+		l := langOf(r)
+		body := strings.ReplaceAll(r.FormValue("body"), "\r\n", "\n")
+		note := strings.TrimSpace(r.FormValue("note"))
+		base, _ := strconv.ParseInt(r.FormValue("base"), 10, 64)
+		// The audit line records the form; the document can hold webhook
+		// secrets, so it records the document's size, not the document.
+		r.PostForm.Set("body", "("+strconv.Itoa(len(body))+" bytes)")
+		refuse := func(msg string) {
+			noteAudit(r, "cluster settings", "", msg)
+			page(w, r, admin, settingsPageData{Body: body, Note: note, Error: msg})
+		}
+		if cur, err := s.ClusterSettings(r.Context()); err == nil && cur.Body == body {
+			refuse(l.T("settings.err.unchanged"))
+			return
+		}
+		if err := check([]byte(body)); err != nil {
+			refuse(l.T("settings.err.invalid") + " " + err.Error())
+			return
+		}
+		n, err := s.PutClusterSettings(r.Context(), base, body, admin.Email, note)
+		switch {
+		case errors.Is(err, store.ErrSettingsChanged):
+			refuse(l.T("settings.err.changed"))
+			return
+		case err != nil:
+			refuse(l.Err(err))
+			return
+		}
+		noteAudit(r, "cluster settings", "version "+strconv.FormatInt(n, 10), "")
+		page(w, r, admin, settingsPageData{Notice: l.T("settings.saved", n)})
+	}))
+
+	mux.HandleFunc("POST /admin/settings/rollback", adminsOnly(func(w http.ResponseWriter, r *http.Request, admin store.User) {
+		l := langOf(r)
+		n, _ := strconv.ParseInt(r.FormValue("version"), 10, 64)
+		old, err := s.ClusterSettingsAt(r.Context(), n)
+		if err != nil || old.Version == 0 {
+			page(w, r, admin, settingsPageData{Error: l.T("settings.err.no_version")})
+			return
+		}
+		cur, err := s.ClusterSettings(r.Context())
+		if err != nil {
+			page(w, r, admin, settingsPageData{Error: l.Err(err)})
+			return
+		}
+		if err := check([]byte(old.Body)); err != nil {
+			// A version kept before a change to server.yaml may no longer
+			// load beside it; refused here rather than breaking the cluster.
+			noteAudit(r, "cluster settings", "", err.Error())
+			page(w, r, admin, settingsPageData{Error: l.T("settings.err.invalid") + " " + err.Error()})
+			return
+		}
+		v, err := s.PutClusterSettings(r.Context(), cur.Version, old.Body, admin.Email, "back to version "+strconv.FormatInt(n, 10))
+		if err != nil {
+			page(w, r, admin, settingsPageData{Error: l.Err(err)})
+			return
+		}
+		noteAudit(r, "cluster settings", "version "+strconv.FormatInt(v, 10)+" from "+strconv.FormatInt(n, 10), "")
+		page(w, r, admin, settingsPageData{Notice: l.T("settings.rolled_back", n, v)})
+	}))
+}

internal/web/admin_settings_test.go

@@ -0,0 +1,143 @@
+package web
+
+import (
+	"context"
+	"errors"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
+)
+
+type fakeSettings struct{ versions []store.SettingsVersion }
+
+func (f *fakeSettings) ClusterSettings(context.Context) (store.SettingsVersion, error) {
+	if len(f.versions) == 0 {
+		return store.SettingsVersion{}, nil
+	}
+	return f.versions[len(f.versions)-1], nil
+}
+
+func (f *fakeSettings) ClusterSettingsAt(_ context.Context, v int64) (store.SettingsVersion, error) {
+	for _, s := range f.versions {
+		if s.Version == v {
+			return s, nil
+		}
+	}
+	return store.SettingsVersion{}, nil
+}
+
+func (f *fakeSettings) ClusterSettingsHistory(context.Context, int) ([]store.SettingsVersion, error) {
+	out := make([]store.SettingsVersion, len(f.versions))
+	for i, v := range f.versions {
+		out[len(f.versions)-1-i] = v
+	}
+	return out, nil
+}
+
+func (f *fakeSettings) PutClusterSettings(_ context.Context, base int64, body, by, note string) (int64, error) {
+	cur, _ := f.ClusterSettings(context.Background())
+	if base != cur.Version {
+		return 0, store.ErrSettingsChanged
+	}
+	n := cur.Version + 1
+	f.versions = append(f.versions, store.SettingsVersion{Version: n, Body: body, By: by, Note: note, At: time.Now()})
+	return n, nil
+}
+
+type auditSink struct{ events []store.AuditEvent }
+
+func (a *auditSink) WriteAudit(_ context.Context, e store.AuditEvent) error {
+	a.events = append(a.events, e)
+	return nil
+}
+
+func clusterSettingsPage(t *testing.T, user store.User) (*http.ServeMux, *fakeSettings, *auditSink) {
+	t.Helper()
+	s := &fakeSettings{versions: []store.SettingsVersion{{Version: 1, Body: "guard:\n  enabled: true\n", By: "init", At: time.Now()}}}
+	p := NewAccountPages(fakeAccounts{user: user}, nil, nil, "v0", slog.New(slog.NewTextHandler(io.Discard, nil)))
+	sink := &auditSink{}
+	p.SetAudit(sink)
+	mux := http.NewServeMux()
+	p.RegisterAdminSettings(mux, s, func(b []byte) error {
+		if strings.Contains(string(b), "bogus") {
+			return errors.New("unknown key bogus")
+		}
+		return nil
+	}, []string{"listen", "store"})
+	return mux, s, sink
+}
+
+func TestTheSettingsPageIsForAdministratorsOnly(t *testing.T) {
+	for _, u := range []store.User{
+		{ID: "u1", Email: "v@example.com", Role: store.RoleViewer},
+		{ID: "u2", Email: "o@example.com", Role: store.RoleOperator},
+		{ID: "u3", Email: "b@example.com", Role: store.RoleBilling},
+	} {
+		mux, _, _ := clusterSettingsPage(t, u)
+		if w := mirrorGet(t, mux, "/admin/settings"); w.Code != http.StatusNotFound {
+			t.Errorf("%s saw the settings: %d", u.Role, w.Code)
+		}
+	}
+	mux, _, _ := clusterSettingsPage(t, store.User{ID: "a", Email: "a@example.com", IsAdmin: true})
+	body := mirrorGet(t, mux, "/admin/settings").Body.String()
+	for _, want := range []string{"guard:\n  enabled: true", "Version 1, in force", "<code>listen</code>", `href="/admin/settings" aria-current="page"`} {
+		if !strings.Contains(body, want) {
+			t.Errorf("no %q in:\n%s", want, body)
+		}
+	}
+}
+
+func TestSettingsAreCheckedAppliedAndRolledBack(t *testing.T) {
+	mux, s, sink := clusterSettingsPage(t, store.User{ID: "a", Email: "a@example.com", IsAdmin: true})
+	post := func(form url.Values) string {
+		form.Set("csrf", "tok")
+		return mirrorPost(t, mux, "/admin/settings", form).Body.String()
+	}
+	// Refused: does not load. The edit stays in the editor; nothing kept.
+	body := post(url.Values{"base": {"1"}, "body": {"bogus: 1\n"}})
+	if !strings.Contains(body, "unknown key bogus") || !strings.Contains(body, "bogus: 1") || len(s.versions) != 1 {
+		t.Errorf("an invalid document: %d versions\n%s", len(s.versions), body)
+	}
+	// Applied, with its note and who.
+	body = post(url.Values{"base": {"1"}, "body": {"guard:\r\n  enabled: false\r\n"}, "note": {"maintenance"}})
+	if !strings.Contains(body, "Version 2 is in force") || len(s.versions) != 2 ||
+		s.versions[1].Body != "guard:\n  enabled: false\n" || s.versions[1].By != "a@example.com" || s.versions[1].Note != "maintenance" {
+		t.Errorf("applying: %+v\n%s", s.versions, body)
+	}
+	// Made from a version no longer the newest: refused, not overwritten.
+	body = post(url.Values{"base": {"1"}, "body": {"guard:\n  enabled: true\n  x: 1\n"}})
+	if !strings.Contains(body, "someone changed the settings") || len(s.versions) != 2 {
+		t.Errorf("a stale edit: %d versions\n%s", len(s.versions), body)
+	}
+	// An earlier version is shown, and put back as a new one.
+	if body := mirrorGet(t, mux, "/admin/settings?version=1").Body.String(); !strings.Contains(body, "Put version 1 back in force") {
+		t.Errorf("viewing version 1:\n%s", body)
+	}
+	w := mirrorPost(t, mux, "/admin/settings/rollback", url.Values{"csrf": {"tok"}, "version": {"1"}})
+	if len(s.versions) != 3 || s.versions[2].Body != s.versions[0].Body || !strings.Contains(w.Body.String(), "as version 3") {
+		t.Errorf("rollback: %+v\n%s", s.versions, w.Body.String())
+	}
+	// Without the CSRF token, nothing.
+	if w := mirrorPost(t, mux, "/admin/settings", url.Values{"base": {"3"}, "body": {"a: 1\n"}}); w.Code != http.StatusBadRequest || len(s.versions) != 3 {
+		t.Errorf("no token: %d", w.Code)
+	}
+	// Audited, without the document itself: it can hold secrets.
+	var saw bool
+	for _, e := range sink.events {
+		if strings.Contains(e.Detail, "enabled") {
+			t.Errorf("the document is in the audit log: %+v", e)
+		}
+		if e.Action == "POST /admin/settings" && strings.Contains(e.Detail, "version 2") {
+			saw = true
+		}
+	}
+	if !saw {
+		t.Errorf("no audit line for version 2: %+v", sink.events)
+	}
+}

internal/web/chat.go

@@ -54,24 +54,41 @@ type ChatContext struct {
 	Label string
 }
 
+// ChatCollection is a knowledge-base collection the chat can answer from.
+type ChatCollection struct {
+	ID, Label string
+}
+
 type chatData struct {
 	Nav      Nav
 	Contexts []ChatContext
 	Context  string
-	User     store.User
-	Models   []ChatModel
-	CSRF     string
-	Version  string
-	Now      string
+	// Collections are what this person may read in the chosen context;
+	// KnowledgeDefault names the ones its part of the tree answers from
+	// when none is chosen, if any.
+	Collections      []ChatCollection
+	KnowledgeDefault string
+	User             store.User
+	Models           []ChatModel
+	CSRF             string
+	Version          string
+	Now              string
+}
+
+// ChatKnowledge is what the chat page offers to answer from.
+type ChatKnowledge struct {
+	Collections []ChatCollection
+	Default     string
 }
 
 // Chat renders the in-browser chat for one signed-in person.
-func Chat(user store.User, models []ChatModel, contexts []ChatContext, current, version string) http.HandlerFunc {
+func Chat(user store.User, models []ChatModel, contexts []ChatContext, current, version string, kb ChatKnowledge) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		noStore(w)
 		render(w, r, "chat", chatData{
 			Nav:      navFrom(r, "chat"),
 			Contexts: contexts, Context: current,
+			Collections: kb.Collections, KnowledgeDefault: kb.Default,
 			User: user, Models: models, CSRF: csrfFor(r),
 			Version: version, Now: time.Now().UTC().Format(time.RFC3339),
 		})

internal/web/chat_test.go

@@ -20,7 +20,7 @@ func chatPage(t *testing.T, names ...string) string {
 
 func chatPageWith(t *testing.T, models []ChatModel) string {
 	t.Helper()
-	h := Chat(store.User{Email: "a@example.com"}, models, nil, "", "v1")
+	h := Chat(store.User{Email: "a@example.com"}, models, nil, "", "v1", ChatKnowledge{})
 	r := httptest.NewRequest(http.MethodGet, "http://x/chat", nil)
 	w := httptest.NewRecorder()
 	h(w, r)

internal/web/i18n_chat_test.go

@@ -12,7 +12,8 @@ import (
 
 func TestTheChatPageSpeaksTurkishWhenAsked(t *testing.T) {
 	h := Chat(store.User{Email: "a@example.com"},
-		[]ChatModel{{Name: "qwen"}, {Name: "big-model", Simulated: true}}, nil, "", "v1")
+		[]ChatModel{{Name: "qwen"}, {Name: "big-model", Simulated: true}}, nil, "", "v1",
+		ChatKnowledge{Collections: []ChatCollection{{ID: "kb_x", Label: "politikalar"}}, Default: "politikalar"})
 	r := httptest.NewRequest(http.MethodGet, "http://x/chat", nil)
 	r.Header.Set("Accept-Language", "tr-TR,tr;q=0.9")
 	w := httptest.NewRecorder()
@@ -31,12 +32,18 @@ func TestTheChatPageSpeaksTurkishWhenAsked(t *testing.T) {
 		// The script's own words come from the catalogue too.
 		`"Uzunluk sınırında kesildi — devam etmesini isteyin."`,
 		`decimal: ","`,
+		// The documents picker, with the default named.
+		"Belgeler",
+		`<option value="">varsayılan (politikalar)</option>`,
+		`<option value="none">yok</option>`,
+		`<option value="kb_x">politikalar</option>`,
+		`"Kaynaklar:"`,
 	} {
 		if !strings.Contains(page, want) {
 			t.Errorf("the Turkish chat page does not have %q", want)
 		}
 	}
-	for _, not := range []string{"New conversation", "Cut off at the length limit", "Ask something"} {
+	for _, not := range []string{"New conversation", "Cut off at the length limit", "Ask something", "Documents", "Sources:"} {
 		if strings.Contains(page, not) {
 			t.Errorf("the Turkish chat page still says %q", not)
 		}

internal/web/locales/en/chat.json

@@ -19,7 +19,6 @@
   "chat.kept": "The conversation is kept in this browser, so a reload does not lose it; \"New conversation\" clears it. Nothing of it is stored on the gateway — what is recorded there is the same usage any request records: tokens, cost and latency.",
   "chat.empty": "No models are available to you right now.",
   "chat.empty_why": "Either nothing is placed yet, or your project's allowlist does not include anything that is. <code>/admin</code> shows the cluster if you have access to it.",
-
   "chat.js.preparing": "Preparing…",
   "chat.js.download_failed": "download failed",
   "chat.js.stage.waiting": "Waiting for a node with room",
@@ -41,7 +40,10 @@
   "chat.js.stopped_by_policy_empty": "(stopped by the gateway's policy{policy} before anything was shown)",
   "chat.js.stopped_empty": "(stopped before anything came back)",
   "chat.js.no_content": "(no content came back)",
-
   "download.err.read": "could not read the request",
-  "download.err.no_code": "there is no code in that reply to download"
+  "download.err.no_code": "there is no code in that reply to download",
+  "chat.knowledge": "Documents",
+  "chat.knowledge.default": "default",
+  "chat.knowledge.none": "none",
+  "chat.js.sources": "Sources:"
 }

internal/web/locales/en/nav.json

@@ -10,5 +10,6 @@
   "nav.chat": "Chat",
   "nav.account": "Account",
   "nav.sign_out": "Sign out",
-  "nav.docs": "Docs"
+  "nav.docs": "Docs",
+  "nav.settings": "Settings"
 }

internal/web/locales/en/settings.json

@@ -0,0 +1,28 @@
+{
+  "settings.title": "Settings",
+  "settings.sub": "The cluster's settings: everything that is not one machine's own, the same on every control plane, in force within seconds of a change. <code>llmgw ctl config edit</code> edits the same document.",
+  "settings.current": "Version %d, in force",
+  "settings.earlier": "Version %d",
+  "settings.earlier_sub": "An earlier version; version %d is in force. Rolling back keeps this one as a new version, so nothing is lost.",
+  "settings.rollback": "Put version %d back in force",
+  "settings.back_to_current": "back to the version in force",
+  "settings.local_keys": "Not here, because each machine's server.yaml keeps them:",
+  "settings.note": "Why",
+  "settings.note_hint": "kept with the version, for whoever reads the history",
+  "settings.save": "Check and apply",
+  "settings.save_hint": "Checked as a control plane would load it before it is kept; a change made since this page was opened is not overwritten.",
+  "settings.saved": "Version %d is in force; every control plane applies it within seconds.",
+  "settings.rolled_back": "Version %d's settings are back in force, as version %d.",
+  "settings.history": "History",
+  "settings.col.version": "Version",
+  "settings.col.at": "When",
+  "settings.col.by": "By",
+  "settings.col.note": "Why",
+  "settings.in_force": "in force",
+  "settings.view": "view",
+  "settings.no_history": "No versions yet.",
+  "settings.err.unchanged": "Nothing was changed.",
+  "settings.err.invalid": "Not applied: a control plane could not load it.",
+  "settings.err.changed": "Not applied: someone changed the settings since this page was opened. Your edit is below; compare it with the version now in force and apply it again.",
+  "settings.err.no_version": "There is no such version."
+}

internal/web/locales/tr/chat.json

@@ -19,7 +19,6 @@
   "chat.kept": "Sohbet bu tarayıcıda saklanır; sayfayı yenilemek onu silmez, \"Yeni sohbet\" temizler. Ağ geçidinde sohbetten hiçbir şey saklanmaz — orada kaydedilen, her isteğin kaydettiği kullanımla aynıdır: token, maliyet ve gecikme.",
   "chat.empty": "Şu anda kullanabileceğiniz bir model yok.",
   "chat.empty_why": "Ya henüz hiçbir model yerleştirilmedi ya da projenizin izin listesi yerleştirilmiş olanların hiçbirini içermiyor. Erişiminiz varsa <code>/admin</code> kümeyi gösterir.",
-
   "chat.js.preparing": "Hazırlanıyor…",
   "chat.js.download_failed": "indirme başarısız oldu",
   "chat.js.stage.waiting": "Yeri olan bir düğüm bekleniyor",
@@ -41,7 +40,10 @@
   "chat.js.stopped_by_policy_empty": "(hiçbir şey gösterilmeden ağ geçidinin politikası{policy} tarafından durduruldu)",
   "chat.js.stopped_empty": "(hiçbir yanıt gelmeden durduruldu)",
   "chat.js.no_content": "(hiçbir içerik gelmedi)",
-
   "download.err.read": "istek okunamadı",
-  "download.err.no_code": "bu yanıtta indirilecek kod yok"
+  "download.err.no_code": "bu yanıtta indirilecek kod yok",
+  "chat.knowledge": "Belgeler",
+  "chat.knowledge.default": "varsayılan",
+  "chat.knowledge.none": "yok",
+  "chat.js.sources": "Kaynaklar:"
 }

internal/web/locales/tr/nav.json

@@ -10,5 +10,6 @@
   "nav.chat": "Sohbet",
   "nav.account": "Hesap",
   "nav.sign_out": "Çıkış yap",
-  "nav.docs": "Belgeler"
+  "nav.docs": "Belgeler",
+  "nav.settings": "Ayarlar"
 }

internal/web/locales/tr/settings.json

@@ -0,0 +1,28 @@
+{
+  "settings.title": "Ayarlar",
+  "settings.sub": "Kümenin ayarları: tek bir makineye ait olmayan her şey; her kontrol düzleminde aynı, değiştikten saniyeler sonra yürürlükte. <code>llmgw ctl config edit</code> aynı belgeyi düzenler.",
+  "settings.current": "Sürüm %d, yürürlükte",
+  "settings.earlier": "Sürüm %d",
+  "settings.earlier_sub": "Önceki bir sürüm; yürürlükte olan sürüm %d. Geri almak bunu yeni bir sürüm olarak kaydeder, hiçbir şey kaybolmaz.",
+  "settings.rollback": "%d numaralı sürümü yeniden yürürlüğe koy",
+  "settings.back_to_current": "yürürlükteki sürüme dön",
+  "settings.local_keys": "Burada değil, çünkü her makinenin kendi server.yaml dosyası tutar:",
+  "settings.note": "Neden",
+  "settings.note_hint": "sürümle birlikte saklanır, geçmişi okuyacak kişi için",
+  "settings.save": "Denetle ve uygula",
+  "settings.save_hint": "Saklanmadan önce bir kontrol düzleminin yükleyeceği gibi denetlenir; bu sayfa açıldıktan sonra yapılmış bir değişikliğin üzerine yazılmaz.",
+  "settings.saved": "%d numaralı sürüm yürürlükte; her kontrol düzlemi saniyeler içinde uygular.",
+  "settings.rolled_back": "%d numaralı sürümün ayarları yeniden yürürlükte; yeni sürüm numarası %d.",
+  "settings.history": "Geçmiş",
+  "settings.col.version": "Sürüm",
+  "settings.col.at": "Ne zaman",
+  "settings.col.by": "Kim",
+  "settings.col.note": "Neden",
+  "settings.in_force": "yürürlükte",
+  "settings.view": "görüntüle",
+  "settings.no_history": "Henüz sürüm yok.",
+  "settings.err.unchanged": "Hiçbir şey değiştirilmedi.",
+  "settings.err.invalid": "Uygulanmadı: bir kontrol düzlemi bunu yükleyemezdi.",
+  "settings.err.changed": "Uygulanmadı: bu sayfa açıldıktan sonra biri ayarları değiştirdi. Düzenlemeniz aşağıda; yürürlükteki sürümle karşılaştırıp yeniden uygulayın.",
+  "settings.err.no_version": "Böyle bir sürüm yok."
+}

internal/web/nav.go

@@ -26,6 +26,9 @@ type Nav struct {
 	Mirror, Quotas bool
 	// Guard is whether the guardrails page was mounted.
 	Guard bool
+	// Settings offers the cluster's settings: mounted, and to an
+	// administrator only.
+	Settings bool
 	// CSRF signs the sign-out form.
 	CSRF string
 	// Org offers the organization page: to an administrator, and to anyone
@@ -38,13 +41,14 @@ type navKey struct{}
 // navFor builds the menu for a signed-in person.
 func (p *AccountPages) navFor(r *http.Request, user store.User, current string) Nav {
 	n := Nav{
-		Current: current,
-		Admin:   user.Staff(),
-		Role:    user.StaffRole(),
-		Mirror:  p.hasMirror,
-		Quotas:  p.hasQuotas,
-		Guard:   p.hasGuard,
-		CSRF:    csrfFor(r),
+		Current:  current,
+		Admin:    user.Staff(),
+		Role:     user.StaffRole(),
+		Mirror:   p.hasMirror,
+		Quotas:   p.hasQuotas,
+		Guard:    p.hasGuard,
+		Settings: p.hasSettings && user.IsAdmin,
+		CSRF:     csrfFor(r),
 	}
 	// Only when there is an organization to show: a link that leads to "there
 	// are none" on every page is noise.

internal/web/static/base.css

@@ -905,3 +905,13 @@ a.sel-link.small { font-size: .78rem; color: var(--muted); margin-left: .4rem; }
 /* The language switcher at the foot of every page. */
 .langs a { color: var(--muted); }
 .langs b { font-weight: 600; }
+
+/* The cluster's settings, edited as the YAML document they are. */
+.settings-form textarea, pre.settings-body {
+  width: 100%; box-sizing: border-box; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
+  font-size: .85rem; line-height: 1.4; padding: .6rem .7rem; border: 1px solid var(--line);
+  border-radius: 6px; background: var(--card); color: var(--fg); tab-size: 2; overflow-x: auto;
+}
+.settings-form label { display: block; margin: .8rem 0; }
+.settings-form input[type=text] { width: 100%; box-sizing: border-box; }
+.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

internal/web/templates/admin_settings.html

@@ -0,0 +1,50 @@
+{{define "admin_settings"}}<!doctype html>
+<html lang="{{lang}}"><head>
+<meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
+<title>{{t "settings.title"}} · llmgw</title><link rel="stylesheet" href="{{stylesheet}}">
+</head><body><div class="wrap">
+<header>
+  <h1>{{t "settings.title"}}</h1>
+  <p class="sub">{{th "settings.sub"}}</p>
+  {{template "nav" .Nav}}
+</header>
+{{if .Error}}<p class="error" role="alert">{{.Error}}</p>{{end}}
+{{if .Notice}}<p class="ok" role="status">{{.Notice}}</p>{{end}}
+
+{{if .Earlier}}
+<h2>{{t "settings.earlier" .Shown.Version}}</h2>
+<p class="sub">{{t "settings.earlier_sub" .Current.Version}}</p>
+<pre class="settings-body">{{.Body}}</pre>
+<form method="post" action="/admin/settings/rollback">
+  <input type="hidden" name="csrf" value="{{.CSRF}}">
+  <input type="hidden" name="version" value="{{.Shown.Version}}">
+  <button type="submit">{{t "settings.rollback" .Shown.Version}}</button>
+  <a href="/admin/settings">{{t "settings.back_to_current"}}</a>
+</form>
+{{else}}
+<h2>{{t "settings.current" .Current.Version}}</h2>
+{{if .LocalKeys}}<p class="sub">{{t "settings.local_keys"}} {{range $i, $k := .LocalKeys}}{{if $i}}, {{end}}<code>{{$k}}</code>{{end}}.</p>{{end}}
+<form method="post" action="/admin/settings" class="settings-form">
+  <input type="hidden" name="csrf" value="{{.CSRF}}">
+  <input type="hidden" name="base" value="{{.Current.Version}}">
+  <label for="settings-body" class="sr-only">{{t "settings.title"}}</label>
+  <textarea id="settings-body" name="body" rows="30" spellcheck="false" class="mono">{{.Body}}</textarea>
+  <label>{{t "settings.note"}} <span class="opt">{{t "settings.note_hint"}}</span>
+    <input type="text" name="note" value="{{.Note}}" maxlength="200"></label>
+  <button type="submit">{{t "settings.save"}}</button>
+  <p class="sub">{{t "settings.save_hint"}}</p>
+</form>
+{{end}}
+
+<h2>{{t "settings.history"}}</h2>
+{{if .History}}
+<table class="rows">
+<tr><th class="num">{{t "settings.col.version"}}</th><th>{{t "settings.col.at"}}</th><th>{{t "settings.col.by"}}</th><th>{{t "settings.col.note"}}</th><th></th></tr>
+{{range .History}}<tr{{if .Selected}} aria-current="true"{{end}}>
+  <td class="num">{{.Version}}</td><td>{{.At}}</td><td>{{.By}}</td><td>{{.Note}}</td>
+  <td>{{if .InForce}}<strong>{{t "settings.in_force"}}</strong>{{else}}<a href="/admin/settings?version={{.Version}}">{{t "settings.view"}}</a>{{end}}</td>
+</tr>{{end}}
+</table>
+{{else}}<p class="sub">{{t "settings.no_history"}}</p>{{end}}
+<footer>llmgw {{.Version}}</footer>
+</div></body></html>{{end}}

internal/web/templates/chat.html

@@ -34,6 +34,13 @@
   <label class="inline-label">{{t "chat.model"}}
     <select id="model">{{range .Models}}<option value="{{.Name}}" data-simulated="{{if .Simulated}}1{{else}}0{{end}}" data-ondemand="{{if .OnDemand}}1{{else}}0{{end}}">{{.Name}}{{with .Runs}} · {{.}}{{end}}{{if .Simulated}} {{t "chat.model.simulated"}}{{end}}{{if .OnDemand}} {{t "chat.model.not_loaded"}}{{end}}</option>{{end}}</select>
   </label>
+  {{if .Collections}}<label class="inline-label">{{t "chat.knowledge"}}
+    <select id="knowledge">
+      {{if .KnowledgeDefault}}<option value="">{{t "chat.knowledge.default"}} ({{.KnowledgeDefault}})</option>
+      <option value="none">{{t "chat.knowledge.none"}}</option>{{else}}<option value="none">{{t "chat.knowledge.none"}}</option>{{end}}
+      {{range .Collections}}<option value="{{.ID}}">{{.Label}}</option>{{end}}
+    </select>
+  </label>{{end}}
   <button id="reset" type="button" class="link">{{t "chat.new"}}</button>
 </div>
 
@@ -89,6 +96,7 @@
     downloadZip: {{t "chat.js.download_zip"}},
     stoppedByPolicy: {{t "chat.js.stopped_by_policy"}},
     cutOff: {{t "chat.js.cut_off"}},
+    sources: {{t "chat.js.sources"}},
     stoppedByPolicyEmpty: {{t "chat.js.stopped_by_policy_empty"}},
     stoppedEmpty: {{t "chat.js.stopped_empty"}},
     noContent: {{t "chat.js.no_content"}},
@@ -381,6 +389,7 @@
         method: "POST",
         headers: { "Content-Type": "application/json", "X-CSRF-Token": csrf },
         body: JSON.stringify({ model: model.value, context: ctxValue(), temperature: +temp.value,
+          knowledge: (document.getElementById("knowledge") || {}).value || "",
           messages: (system ? [{ role: "system", content: system }] : []).concat(messages) }),
         signal: busy.signal,
       });
@@ -478,6 +487,16 @@
           note.textContent = say.cutOff;
           out.after(note);
         }
+        // Which passages of the documents it was given, numbered as the
+        // reply cites them. Ours, so a sibling placed with textContent.
+        const src = resp.headers.get("x-llmgw-sources");
+        if (src) {
+          const note = document.createElement("p");
+          note.className = "note sources";
+          note.textContent = say.sources + " " + src.split(",").map((s, i) =>
+            "[" + (i + 1) + "] " + decodeURIComponent(s.split("#")[0])).join("  ");
+          out.after(note);
+        }
         stats(out, tokens || pieces, t0, tFirst, performance.now(), stopped, resp.headers.get("x-llmgw-hardware"));
         // Once, at the end. Re-rendering every chunk would try to typeset half
         // an expression on each token and flicker its way through the reply.

internal/web/templates/nav.html

@@ -20,6 +20,9 @@
   {{- if .Guard}}
   <a href="/admin/guard"{{if eq .Current "guard"}} aria-current="page"{{end}}>{{t "nav.guard"}}</a>
   {{- end}}
+  {{- if .Settings}}
+  <a href="/admin/settings"{{if eq .Current "settings"}} aria-current="page"{{end}}>{{t "nav.settings"}}</a>
+  {{- end}}
   {{- /* An organization is a panel of the people page for an administrator;
        /org is the managers' view, and leads an administrator there. */}}
   <span class="menu-gap" aria-hidden="true"></span>