on_tool_start() — langchain Function Reference

Architecture documentation for the on_tool_start() function in base.py from the langchain codebase.

Function python Observability TelemetryUtilities calls 1 called by 1

Entity Profile

Observability→ TelemetryUtilities→ on_tool_start() — langchain Function Reference

Dependency Diagram

graph TD
  bd9adcfb_46ad_bf3c_08e4_e61850e1adaa["on_tool_start()"]
  3b53de05_0697_704a_50e8_c5f9aaeba5ae["CallbackManagerMixin"]
  bd9adcfb_46ad_bf3c_08e4_e61850e1adaa -->|defined in| 3b53de05_0697_704a_50e8_c5f9aaeba5ae
  da773f46_5434_347c_04fa_733ddda9275b["on_tool_start()"]
  da773f46_5434_347c_04fa_733ddda9275b -->|calls| bd9adcfb_46ad_bf3c_08e4_e61850e1adaa
  da773f46_5434_347c_04fa_733ddda9275b["on_tool_start()"]
  bd9adcfb_46ad_bf3c_08e4_e61850e1adaa -->|calls| da773f46_5434_347c_04fa_733ddda9275b
  style bd9adcfb_46ad_bf3c_08e4_e61850e1adaa fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/callbacks/base.py lines 348–371

    def on_tool_start(
        self,
        serialized: dict[str, Any],
        input_str: str,
        *,
        run_id: UUID,
        parent_run_id: UUID | None = None,
        tags: list[str] | None = None,
        metadata: dict[str, Any] | None = None,
        inputs: dict[str, Any] | None = None,
        **kwargs: Any,
    ) -> Any:
        """Run when the tool starts running.

        Args:
            serialized: The serialized chain.
            input_str: The input string.
            run_id: The ID of the current run.
            parent_run_id: The ID of the parent run.
            tags: The tags.
            metadata: The metadata.
            inputs: The inputs.
            **kwargs: Additional keyword arguments.
        """