feat(openrouter,fireworks): support response_format on invoke and bind_tools - #40390
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…ind_tools `ChatOpenRouter` and `ChatFireworks` accept `response_format` as a Pydantic model class, `TypedDict` class, dataclass, JSON schema dict, or an OpenAI-style `json_schema` envelope — the shape `ProviderStrategy` emits for `create_agent(response_format=...)`. Previously these schemas only worked via `with_structured_output`; passing them through `invoke(..., response_format=...)` or `bind_tools(response_format=...)` forwarded the raw class object to the API, causing serialization errors or API rejections. Co-authored-by: open-swe[bot] <[email protected]>
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| if envelope_type in ("json_object", "json_schema", "text"): | ||
| # Already a `response_format` the API understands | ||
| return schema |
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🟡 Preserve Fireworks grammar response format support
Fireworks supports response_format={"type": "grammar", "grammar": 'root ::= "yes" | "no"'} (provider documentation). Previously this was forwarded to the client, but the new normalization excludes grammar from the passthrough branch and falls through to convert_to_json_schema, which raises ValueError because this dictionary has no function name or schema title. This breaks existing grammar-mode calls in all four generation paths, including streaming and async. Preserve the grammar envelope and add a regression test.
(Refers to lines 177-179)
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| if envelope_type in ("json_object", "json_schema", "text"): | |
| # Already a `response_format` the API understands | |
| return schema | |
| if envelope_type in ("json_object", "json_schema", "text", "grammar"): | |
| # Already a `response_format` the API understands | |
| return schema |
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ChatOpenRouterandChatFireworksnow acceptresponse_formatas a Pydantic model class,TypedDictclass, dataclass, JSON schema dict, or an OpenAI-style{"type": "json_schema", "json_schema": {...}}envelope — on bothinvoke(..., response_format=...)andbind_tools(response_format=...).create_agent'sProviderStrategybinds this envelope shape, socreate_agent(response_format=MySchema)silently failed to enforce structured output on OpenRouter and Fireworks. Direct schema support also simplifies structured output flows (e.g. deepagents) that previously had to route throughwith_structured_output.json_schemaenvelope and pass existingjson_object/textenvelopes through untouched.strictis forwarded when explicitly provided.ChatOpenAI,ChatAnthropic(viaoutput_config.format), andChatOllama(viaformat) already handled these shapes; this brings OpenRouter and Fireworks to parity.Release note
langchain-openrouterandlangchain-fireworkschat models now supportresponse_format(Pydantic model,TypedDict, dataclass, JSON schema, or OpenAI-stylejson_schemaenvelope) when passed directly toinvoke/bind_tools, enabling native structured output throughcreate_agent'sProviderStrategy.AI-agent involvement: this contribution was prepared collaboratively with Open SWE; a human reviewer should verify the schema-conversion edge cases.
Made by Open SWE · openai:gpt-5.6-sol (high)