The adapter builds the Messages body from a fixed allow-list of kwargs.
A caller that passes response_format as a top-level kwarg (the OpenAI
SDK call shape) got it dropped on the floor. The request succeeded, but
the schema contract silently became prompt compliance. No in-tree
caller uses this shape today. The pin-test makes sure that a future
refactor cannot open this leak again.
The top-level kwarg gets the same output_config.format translation as
the extra_body shape. When a caller sends both shapes, the extra_body
value wins because every in-tree caller uses that shape.
Pin-test pattern from PR #85626 review follow-up.
Co-authored-by: Matt McClean <mmcclean@amazon.com>
Plugin structured completions (plugin_llm.complete_structured) build an
OpenAI Chat Completions response_format payload in extra_body. The
anthropic_messages transport forwarded it verbatim, and strict
Anthropic-compatible gateways reject it with HTTP 400:
response_format: OpenAI Chat Completions structured-output shape is
not supported. Use output_config.format = {"type": "json_schema", ...}
Observed live: every discord-thread-autotitle structured call failed
for 2+ days (1,600+ logged errors) once the main provider became an
anthropic_messages gateway.
Fix: _translate_anthropic_response_format converts
- json_schema -> output_config.format = {type: json_schema, schema: S}
- json_object -> permissive object schema (SDK 0.87.0 has no
schema-less JSON mode)
merging into any existing output_config (adaptive-thinking effort
coexists) and excluding response_format from the raw extra_body
passthrough alongside the existing reasoning exclusion. The async
adapter delegates to the sync adapter via asyncio.to_thread and is
covered by a test. Non-Anthropic transports are unchanged.
ethernet