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BackwardsCompatibleMiddleware Class — langchain Architecture

Architecture documentation for the BackwardsCompatibleMiddleware class in test_middleware_typing.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  95840e43_8c88_a8e3_85de_d533eef1fd15["BackwardsCompatibleMiddleware"]
  949c7cf4_56fe_f3b4_cd89_9631a7e9cb1e["AgentMiddleware"]
  95840e43_8c88_a8e3_85de_d533eef1fd15 -->|extends| 949c7cf4_56fe_f3b4_cd89_9631a7e9cb1e
  689eac1f_5845_440c_f60b_988968e02ee6["test_middleware_typing.py"]
  95840e43_8c88_a8e3_85de_d533eef1fd15 -->|defined in| 689eac1f_5845_440c_f60b_988968e02ee6
  ac0a228c_341d_f10a_26cf_b94cfdb9608c["before_model()"]
  95840e43_8c88_a8e3_85de_d533eef1fd15 -->|method| ac0a228c_341d_f10a_26cf_b94cfdb9608c
  9c7f4825_7b9a_f7c4_6425_46a4925008e5["wrap_model_call()"]
  95840e43_8c88_a8e3_85de_d533eef1fd15 -->|method| 9c7f4825_7b9a_f7c4_6425_46a4925008e5

Relationship Graph

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware_typing/test_middleware_typing.py lines 78–89

class BackwardsCompatibleMiddleware(AgentMiddleware):
    """Middleware that doesn't specify type parameters - backwards compatible."""

    def before_model(self, state: AgentState[Any], runtime: Runtime[None]) -> dict[str, Any] | None:
        return None

    def wrap_model_call(
        self,
        request: ModelRequest,  # No type param - backwards compatible!
        handler: Callable[[ModelRequest], ModelResponse],
    ) -> ModelResponse:
        return handler(request)

Defined In

Extends

Source

Frequently Asked Questions

What is the BackwardsCompatibleMiddleware class?
BackwardsCompatibleMiddleware is a class in the langchain codebase, defined in libs/langchain_v1/tests/unit_tests/agents/middleware_typing/test_middleware_typing.py.
Where is BackwardsCompatibleMiddleware defined?
BackwardsCompatibleMiddleware is defined in libs/langchain_v1/tests/unit_tests/agents/middleware_typing/test_middleware_typing.py at line 78.
What does BackwardsCompatibleMiddleware extend?
BackwardsCompatibleMiddleware extends AgentMiddleware.

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