mirror of
https://github.com/hwchase17/langchain.git
synced 2026-07-12 11:21:37 +00:00
cf08ef0a29
Fixes #36581 ## Problem `ChatOpenRouter` had no way to set custom HTTP headers on requests to OpenRouter. Passing `default_headers` to the constructor silently misfired: `build_extra` treated it as an unrecognized kwarg, emitted a "transferred to model_kwargs" warning, and dumped the header into the request body instead of the HTTP layer. This blocked any feature that needs per-request header injection — for example xAI's `x-grok-conv-id` for sticky-routing prompt cache hits. ## What changed - `default_headers` is now a first-class field on `ChatOpenRouter` (`Mapping[str, str] | None`). Because headers may carry credentials, the field is excluded from serialization. - User-supplied headers are merged with the built-in app-attribution headers (`HTTP-Referer`, `X-Title`, `X-OpenRouter-Categories`). On collision the user value wins; because HTTP header names are case-insensitive, the merge drops any built-in whose name case-insensitively matches a user header before applying, so `http-referer` replaces `HTTP-Referer` rather than producing a doubled header. - Corrected the documented `session_id` length limit from 128 to 256 characters. Example: ChatOpenRouter( model="x-ai/grok-4", default_headers={"x-grok-conv-id": "session-abc123"}, ) --------- Co-authored-by: Mason Daugherty <github@mdrxy.com>