abefore_model() — langchain Function Reference

Architecture documentation for the abefore_model() function in pii.py from the langchain codebase.

Function python LangChainCore LanguageModelBase calls 1

Entity Profile

LangChainCore→ LanguageModelBase→ abefore_model() — langchain Function Reference

Dependency Diagram

graph TD
  9c796f5d_d259_f87b_dbac_56cc6e575e35["abefore_model()"]
  dc527b75_da40_4d1c_e472_82d1252ba70b["PIIMiddleware"]
  9c796f5d_d259_f87b_dbac_56cc6e575e35 -->|defined in| dc527b75_da40_4d1c_e472_82d1252ba70b
  e81931fa_c61c_8dac_e9d4_8b63fbff471d["before_model()"]
  9c796f5d_d259_f87b_dbac_56cc6e575e35 -->|calls| e81931fa_c61c_8dac_e9d4_8b63fbff471d
  style 9c796f5d_d259_f87b_dbac_56cc6e575e35 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/langchain_v1/langchain/agents/middleware/pii.py lines 266–284

    async def abefore_model(
        self,
        state: AgentState[Any],
        runtime: Runtime[ContextT],
    ) -> dict[str, Any] | None:
        """Async check user messages and tool results for PII before model invocation.

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

        Returns:
            Updated state with PII handled according to strategy, or `None` if no PII
                detected.

        Raises:
            PIIDetectionError: If PII is detected and strategy is `'block'`.
        """
        return self.before_model(state, runtime)