FullyTypedMiddleware Class — langchain Architecture

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware_typing/test_middleware_typing.py lines 192–211

class FullyTypedMiddleware(
    AgentMiddleware[AgentState[AnalysisResult], UserContext, AnalysisResult]
):
    """Middleware with both ContextT and ResponseT fully specified."""

    def wrap_model_call(
        self,
        request: ModelRequest[UserContext],
        handler: Callable[[ModelRequest[UserContext]], ModelResponse[AnalysisResult]],
    ) -> ModelResponse[AnalysisResult]:
        # Access context with full type safety
        _user_id: str = request.runtime.context["user_id"]

        response = handler(request)

        # Access structured response with full type safety
        if response.structured_response is not None:
            _sentiment: str = response.structured_response.sentiment

        return response