Method on_tool_start

libs/core/langchain_core/tracers/base.py:239–266

Start a trace for a tool run.

(
        self,
        serialized: Dict[str, Any],
        input_str: str,
        *,
        run_id: UUID,
        tags: Optional[List[str]] = None,
        parent_run_id: Optional[UUID] = None,
        metadata: Optional[Dict[str, Any]] = None,
        name: Optional[str] = None,
        inputs: Optional[Dict[str, Any]] = None,
        **kwargs: Any,
    )

        return chain_run

    def on_tool_start(
        self,
        serialized: Dict[str, Any],
        input_str: str,
        *,
        run_id: UUID,
        tags: Optional[List[str]] = None,
        parent_run_id: Optional[UUID] = None,
        metadata: Optional[Dict[str, Any]] = None,
        name: Optional[str] = None,
        inputs: Optional[Dict[str, Any]] = None,
        **kwargs: Any,
    ) -> Run:
        """Start a trace for a tool run."""
        tool_run = self._create_tool_run(
            serialized=serialized,
            input_str=input_str,
            run_id=run_id,
            tags=tags,
            parent_run_id=parent_run_id,
            metadata=metadata,
            name=name,
            inputs=inputs,
            **kwargs,
        )
        self._start_trace(tool_run)
        self._on_tool_start(tool_run)
        return tool_run

    def on_tool_end(self, output: Any, *, run_id: UUID, **kwargs: Any) -> Run:
        """End a trace for a tool run."""