llmgw/docs/data.md

What llmgw stores, and what leaves the machine

Written for the review that happens before a gateway is allowed near anyone's documents. It describes what the software does. Mapping that onto an obligation — GDPR, a sector rule, an internal policy — is work for whoever holds the obligation; this page exists so that work starts from facts rather than from a vendor's summary.

Everything below is checkable in the source, and the places to look are named.

The short version

By default llmgw stores no prompt or completion text anywhere. It stores who made a request, when, how many tokens, and what it cost.

Two features change that, and both are off until somebody turns them on for a named project, and neither can be turned on without also saying for how long.

Nothing on the serving path leaves the cluster — unless the catalog has a model served outside it (external: in a model definition): a request for that model, or one that falls back to it, sends its prompt to that provider. A guardrail policy with no_store refuses both for the scopes it covers.

Guardrails read every prompt and answer they are configured for, in the gateway's own memory, to judge them. What they record — in the usage row and the log — is the action, the policy, the category and how long it took: never the text, the value that matched, or the placeholder map of a redaction. See guardrails.md.

What is stored, exactly

Usage records, one per request: the key, the project, the model asked for, the model that answered, prompt and completion token counts, cost, HTTP status and latency. No message content. The row is in internal/store/store.go as Usage and there is no field for text in it. What the client chose to say about the request is kept with it: OpenAI's user field and its metadata or x-llmgw-tags — short strings, set by the client, for attributing spend. A client that puts a person's name or address there puts it in the usage records; the field is the client's, and so is that choice. Tags are not sent on to the engine.

API keys, as SHA-256 hashes. The key itself is shown once, at creation, and never stored — so a leaked database hands over no working credential, and neither llmgw nor an administrator can recover a key somebody lost. A prefix is kept so a key can be identified in a listing without revealing it.

The store's own secrets, like the one engine keys are derived from, plain unless secrets.master_key seals them — with Vault's transit engine, so that neither the store nor its backups hold them.

People and tenancy: accounts, the organisation/team/project tree, and the limits attached to it. Passwords are hashed.

Sessions for the browser pages, as tokens.

Conversations and agent notes — only for a project that asked. See below.

Kept requests — only for a project that asked (llmgw keys requests): what each request sent the model, after the guardrails' redaction and with any stored conversation in it, and the answer the client got, for the hours it said, all of them or a share. Never under a no_store policy.

Batch files — when a client uses the Batch API: the file of requests it uploaded (prompts) and the files the batch wrote (answers), in the store, until deleted (DELETE /v1/files/{id}) or, for what a batch wrote, until router.batch.retain_days (30) pass. Only keys of the project that made them can read them, and a project under a no_store policy cannot make them.

What is not stored

Prompts. Completions. Anything the model was shown or produced, unless the project turned on conversations, notes or kept requests, or sent a batch.

The chat page in llmgw's own web interface keeps the conversation in a JavaScript variable in the browser. Refresh it and the conversation is gone, because it was never anywhere else.

Conversations and notes, when they are turned on

Two features keep text, and both work the same way:

• Conversations (x-llmgw-thread) let a client send only its new turn while llmgw replays the history — including to a different model than the one the conversation started on.
• Agent notes (/v1/memory, and MCP tools) let an agent keep something for itself across conversations.

Both are off for every project until an operator runs llmgw keys threads or llmgw keys memory for that project by name. A request carrying a thread id against a project that has not is refused with an explanation, not quietly served without its history.

Both require a retention window. There is no way to turn either on without saying how many hours, because a store with no expiry is a transcript of everything a team ever typed, kept forever because nobody chose a number. The window is measured from the last turn, so an active conversation does not expire underneath it, and a background sweep removes what has passed it.

Both are scoped to a project, and the scope is part of every lookup rather than a check afterwards. Reading a conversation that belongs to another project returns the same answer as reading one that does not exist, so a leaked id cannot be used to discover what exists elsewhere.

DELETE /v1/threads/{id} removes a conversation and its messages immediately. It is a client endpoint, not an administrative one: the person who said the thing can unsay it without asking somebody else to read it first.

Turning retention off stops new storage, and existing conversations go at the next hourly sweep.

What leaves the machine

Nothing on the serving path. A request arrives, is routed to an engine on your own hardware, and the answer comes back. The router talks to engines, the engines talk to nothing, the agents talk to the control plane. All of it is inside the cluster.

Two things can reach outside, both started by an operator rather than by a request:

Fetching weights. When a model's source is a URL, the agent downloads it. Point that at an internal mirror and nothing leaves at all — which is also the faster arrangement, because eight nodes pulling forty gigabytes from the internet is a day's work and from a local mirror it is minutes. A source that is a path on disk is never fetched.

llmgw ctl plan. Reads a model's architecture from huggingface.co to work out whether it fits your hardware. An operator command run at planning time, not part of serving, and not run by anything automatically.

There is no telemetry, no licence check, and no call home. The binary is static, built with CGO_ENABLED=0, and runs in a network with no route to the internet as long as the weights are already on disk.

What the software cannot do for you

The admin port serves pprof, and pprof can dump the process heap — where API keys sit in plaintext while they are being checked. Bind it to loopback and reach it over SSH. The default does this; a deployment that changes it should know why.

The store holds everything. With conversations turned on it holds text as well as accounting, so where it lives, who can read it and how it is backed up are decisions with the same weight as the ones above. The PostgreSQL DSN belongs in a file readable only by the user llmgw runs as, which is why the configuration takes @/path/to/file rather than the address itself.

Model weights are yours. llmgw reclaims only files it downloaded, and it identifies those by a name it generated. Anything you put on a node it will not touch, whatever the catalog says.

Where to look

Claim	Where
Usage rows carry no text	internal/store/store.go, type Usage
Keys are stored hashed	internal/store/keys.go
Conversations are off by default	internal/store/threads.go, ThreadRetention
Retention is required	llmgw keys threads --help
Scope is part of the lookup	internal/store/threads.go, Thread
Deletion is a client endpoint	internal/router/threads.go, handleDeleteThread
Weight fetching is the only serving-path egress	internal/agent/weights/fetch.go