Until now anything that could reach the client port could use every model in
the catalog. A key now resolves to an identity, and that identity decides what
it may do.
Authentication wraps the whole mux rather than checking inside each handler,
so adding a route cannot add an unauthenticated one by omission. Health stays
open, because a load balancer has no key and a health check that needs one
reports the gateway down.
Nothing on the request path reads the database. A key is resolved once and
answered from memory until the entry expires; rejections are cached too, so a
client looping with a bad key cannot turn into a database read per request.
The price is that a revocation takes up to cache_ttl to take effect, which is
the trade stated in the configuration next to the knob. A store failure is
not an authentication answer: it is never cached as one and returns 503, not
401 — sending someone hunting for a key problem that does not exist wastes the
one thing an incident is short of. A revoked key is refused with the same
message as an unknown one, because saying otherwise confirms the key was real.
With auth on the band comes from the key and the band header is ignored. The
header was trusted only while there was nothing to consult, and it let any
client promote itself into the top priority band. Tenant fairness within a
band is now per key rather than per session, so one caller cannot take a band
by opening many sessions.
Allowlists are decided per model, not per string: a model's canonical name and
every alias name the same thing, so either form works in an allowlist and no
alias can reach a model that was not allowed. The first version of that test
passed without the resolution being there at all, which is why it now checks
all four combinations.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
