AI API receipt · BerriAI/litellm
BerriAI/litellm#44815 · upstream bug reproduced by running the issue's own reproduction
Badgr cannot tell this response is wrong
The primary raised UnsupportedParamsError (a deterministic config error); the router answered 200 from the backup model.
the fallback's reply is a perfectly valid answer; the response check cannot tell it came from a different model than the one requested. The receipt therefore records success. This is a limit of what the contract can prove, shown here so it is not mistaken for protection.
The output the bug produces, taken from the issue’s reproduction and fed to Badgr’s validators. Not a live provider call.
text: "FALLBACK_MODEL" tool_calls: none
Written by Badgr’s receipt ledger and read back from GET /v1/receipts/replay-litellm-44815-config-error-hidden-by-fallback.
{
"request_id": "replay-litellm-44815-config-error-hidden-by-fallback",
"status": "success",
"endpoint": "/v1/chat/completions",
"stream": false,
"failure_stage": null,
"error_code": null,
"error_message": null,
"retryable": null,
"provider_mode": "replay",
"routing_decision": "replayed_upstream_output",
"created_at": "1791543162.3201962"
}Recorded 2026-10-09 in Badgr’s local development environment. Replay cases and verdicts are pinned by backend/test_ai_api_replay_cases.py.
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