Build 227 mounted Gemini and turned TestGeminiFiles::test_gemini_file_upload
red. litellm's two Gemini endpoints disagree about what api_base means.
Chat composes {api_base}/models/{model}:{endpoint} and defaults api_base to
https://generativelanguage.googleapis.com/v1beta, so the version lives
inside it. File upload composes {api_base}/upload/v1beta/files and defaults
to the host root, so the version lives outside it. A single api_base cannot
satisfy both, and a registration carries no signal about which endpoint the
deployment will be used for, so the edge cannot route one and not the other.
Backing it out rather than working around it. The cache must never turn a
passing test red, which is the same rule the Bedrock model allowlist
follows, and Gemini was 7 of roughly 1030 edge calls in that build. Anyone
pointing litellm's Gemini provider at an AI gateway or a corporate proxy
hits this too, so the fix belongs in litellm; mounting Gemini is one line
once it lands.
This reverts commit 8a553ceb58.
Gemini needs none of the machinery Bedrock needed. litellm composes
{api_base}/models/{model}:{endpoint} from a custom api_base, so a plain
path-prefixed mount reaches it, and the credential travels as a static
x-goog-api-key header that no host rewrite invalidates. Nothing is
re-signed and nothing leaves the cache key, so a recording still cannot
cross credentials.
A finished turn names a finishReason on every candidate and reports
usageMetadata. The reason is read as a string rather than compared to
STOP: MAX_TOKENS and the safety reasons end a turn just as finally, and
rejecting them would send every one of them upstream forever. Streaming
is the half worth care. Gemini repeats usageMetadata on every chunk and
names a finishReason only on the last, so the terminator is the final
event rather than any event, and a stream the connection cut short ends
on a chunk carrying usage and no reason.
The mount's upstream base carries the API version, so the path the rules
see is /v1beta/models/..., not the one the proxy sent. The first version
of this anchored the rule at the start of that path, which passed every
test against a stub with no version prefix and would have cached nothing
at all in a real run. Caught by replaying the rules over responses
captured from live gemini-2.5-flash, which is also why the tests now
mount their stub under the version prefix.
Vertex stays unmounted and is a separate provider here: litellm grafts
the default Vertex path onto an api_base only when that api_base has no
path of its own, so Vertex needs a root-mounted edge on its own port.
The allowlist rejects an unlisted model before the region resolver runs, so the
two negative cases that used to cover the resolver were passing for the wrong
reason and two mutations of it survived. Answering an env-referenced region with
the default mount is only sound because every allowlisted model is a `us.`
profile that fans out across the US regions, so assert that on the list itself
and drop the per-call branch it made unreachable.
The edge re-signs with the run pod's identity, whose IAM policy is an explicit
per-model allowlist. Matching on the `anthropic.` infix instead routed every
Anthropic-on-Bedrock model, so a model outside the policy came back 403 from
Bedrock with no fallback, taking the whole claude_code Bedrock matrix red.
An unlisted model now keeps its direct path and loses only caching.
Almost every Bedrock deployment in the suite declares
aws_region_name="os.environ/AWS_REGION". The mount resolver treated that
string as a region name, produced a mount nothing serves, and left the whole
Anthropic-on-Bedrock surface on its direct path, which is the one thing
mounting Bedrock was for.
The run pod does not share the proxy's environment, so the harness genuinely
cannot resolve that reference. A `us.` inference profile fans out across the US
regions and is reachable from any of them, so those route to the default mount
whatever the proxy resolved. A model that is not cross-region and declares its
region that way keeps its direct path rather than being sent to a region it may
not exist in.
The exact-request cache reused 5% of routed traffic (build 218: 19 hits,
350 misses) because every test salts its prompt with a fresh unique_marker(),
so the same test could never match itself across builds. It also routed only
openai and anthropic, while the week's flakiness was Bedrock.
Key is now HMAC(test id + method + URL + headers + body, with every
unique_marker() token replaced by a placeholder, + FIFO slot index). The slot
index is what keeps two marker-only-different calls in one test on two
recordings and therefore two provider response ids, so spend rows still
reconcile one per invocation. A call outside any test is not cacheable.
Bedrock gets a region-qualified mount and SigV4 re-signing, since the edge
rewrites the Host the proxy signed. Signature headers are excluded from the
key for signing mounts only, because x-amz-date would otherwise make every
Bedrock request a permanent miss; every other mount still keys on its
credentials whole. Only Anthropic-on-Bedrock chat deployments route:
embeddings, image generation, rerank and realtime keep their direct path, and
so do deployments carrying their own aws_role_name or static keys, whose whole
point is to prove the product's assume-role chain rather than the runner's.
The two eventstream actions bypass the cache and go live, still signed.
Counters are now attributed per mount as well as in total, so a build can
report a per-provider hit rate instead of one number.
