on_llm_start() — langchain Function Reference

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

Function python Observability TelemetryUtilities calls 1 called by 1

Entity Profile

Observability→ TelemetryUtilities→ on_llm_start() — langchain Function Reference

Dependency Diagram

graph TD
  2982d426_3118_c144_0d4b_d101dba16236["on_llm_start()"]
  3b53de05_0697_704a_50e8_c5f9aaeba5ae["CallbackManagerMixin"]
  2982d426_3118_c144_0d4b_d101dba16236 -->|defined in| 3b53de05_0697_704a_50e8_c5f9aaeba5ae
  d132e733_724f_f8b9_75ac_1de3b10fd868["on_llm_start()"]
  d132e733_724f_f8b9_75ac_1de3b10fd868 -->|calls| 2982d426_3118_c144_0d4b_d101dba16236
  d132e733_724f_f8b9_75ac_1de3b10fd868["on_llm_start()"]
  2982d426_3118_c144_0d4b_d101dba16236 -->|calls| d132e733_724f_f8b9_75ac_1de3b10fd868
  style 2982d426_3118_c144_0d4b_d101dba16236 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/callbacks/base.py lines 241–268

    def on_llm_start(
        self,
        serialized: dict[str, Any],
        prompts: list[str],
        *,
        run_id: UUID,
        parent_run_id: UUID | None = None,
        tags: list[str] | None = None,
        metadata: dict[str, Any] | None = None,
        **kwargs: Any,
    ) -> Any:
        """Run when LLM starts running.

        !!! warning

            This method is called for non-chat models (regular text completion LLMs). If
            you're implementing a handler for a chat model, you should use
            `on_chat_model_start` instead.

        Args:
            serialized: The serialized LLM.
            prompts: The prompts.
            run_id: The ID of the current run.
            parent_run_id: The ID of the parent run.
            tags: The tags.
            metadata: The metadata.
            **kwargs: Additional keyword arguments.
        """