before_agent() — langchain Function Reference

Architecture documentation for the before_agent() function in types.py from the langchain codebase.

Function python LangChainCore ApiManagement calls 1 called by 1

Entity Profile

LangChainCore→ ApiManagement→ before_agent() — langchain Function Reference

Dependency Diagram

graph TD
  1962db8c_8abd_47e2_33b1_7245abf9c4ae["before_agent()"]
  949c7cf4_56fe_f3b4_cd89_9631a7e9cb1e["AgentMiddleware"]
  1962db8c_8abd_47e2_33b1_7245abf9c4ae -->|defined in| 949c7cf4_56fe_f3b4_cd89_9631a7e9cb1e
  6caeccd5_e24d_f046_a907_383ed9da89d9["before_agent()"]
  6caeccd5_e24d_f046_a907_383ed9da89d9 -->|calls| 1962db8c_8abd_47e2_33b1_7245abf9c4ae
  6caeccd5_e24d_f046_a907_383ed9da89d9["before_agent()"]
  1962db8c_8abd_47e2_33b1_7245abf9c4ae -->|calls| 6caeccd5_e24d_f046_a907_383ed9da89d9
  style 1962db8c_8abd_47e2_33b1_7245abf9c4ae fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/langchain_v1/langchain/agents/middleware/types.py lines 406–415

    def before_agent(self, state: StateT, runtime: Runtime[ContextT]) -> dict[str, Any] | None:
        """Logic to run before the agent execution starts.

        Args:
            state: The current agent state.
            runtime: The runtime context.

        Returns:
            Agent state updates to apply before agent execution.
        """