[proxy,management] Serve Bedrock model discovery from the control plane
A Bedrock provider could never answer a model-discovery request. The router
sent GET /inference-profiles to the record's upstream, which has to be
bedrock-runtime.<region> for InvokeModel to work, and that host does not
implement the operation. ListInferenceProfiles is a control-plane operation on
bedrock.<region>.amazonaws.com, and one provider record carries one upstream,
so the two hosts genuinely differ.
The route now carries a discovery host, taken from the catalog's declaration
with the region read back out of the configured upstream, and the listing — and
only the listing — goes there. Inference is untouched. A proxied or self-hosted
Bedrock endpoint gets no discovery host at all rather than a guessed one, since
inventing a host would send the operator's credential somewhere they never
configured.
Two things had to follow for the listing to be usable once it arrives. The
response filter only understood OpenAI's {"data":[{"id":…}]}, so a Bedrock
listing fell through it untouched, offering every profile in the account
whatever the policy said. And discoverableModels intersected by exact string,
so a record registering the raw profile id while a guardrail names the catalog
key intersected to nothing — bounding a working provider's listing down to
empty.
Normalisation is the third. The geography in front of a cross-region profile
was matched against a hardcoded list of four, so every profile issued under jp,
au, ca, sa or us-gov carried its prefix into the pricing key, matched no
catalog entry and metered at zero. It is now recognised by either the geography
or the vendor that follows it, so an id has to be new on both axes at once to
slip through — a live eu-central-1 listing returned "global.xai.grok-4.6" days
after the vendor list was first written.
[proxy,management] Bound model discovery to the caller's own policies
GET /v1/models was bounded by the provider record's enumerated models, which is
the right bound only while a single policy reaches a provider. Where two teams
share one provider under different allowlists, every caller was offered the
union — each model outside their own policy being a request the guardrail
refuses a moment later. A gateway record enumerating nothing was worse: it
offered the upstream's entire catalogue however narrow the policy was.
Each route now carries one rule per authorising policy — its source groups and
the models it permits — instead of a single flattened list. At request time the
router keeps the rules whose groups intersect the caller's, unions their
models, and intersects that with what the provider serves.
nil and [] stay distinct end to end: a policy setting no allowlist reaches the
router as nil and lifts the restriction for the groups it binds, while an
enabled allowlist with no models arrives as [] and permits nothing. Collapsing
them would let a listing that should offer nothing fall open to everything.
The guardrail's own per-provider allowlist is untouched. It is a fail-closed
backstop that cannot tell who is asking, so discovery is now narrower than the
backstop rather than wider.
