init() — langchain Function Reference

Architecture documentation for the __init__() function in model_call_limit.py from the langchain codebase.

Function python LangChainCore LanguageModelBase

Entity Profile

LangChainCore→ LanguageModelBase→ __init__() — langchain Function Reference

Dependency Diagram

graph TD
  2a422801_14e5_2ae0_8cda_a0d9c2bb00ac["__init__()"]
  190da0f4_c252_0e20_de0d_30a94a781fc9["ModelCallLimitMiddleware"]
  2a422801_14e5_2ae0_8cda_a0d9c2bb00ac -->|defined in| 190da0f4_c252_0e20_de0d_30a94a781fc9
  style 2a422801_14e5_2ae0_8cda_a0d9c2bb00ac fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/langchain_v1/langchain/agents/middleware/model_call_limit.py lines 126–164

    def __init__(
        self,
        *,
        thread_limit: int | None = None,
        run_limit: int | None = None,
        exit_behavior: Literal["end", "error"] = "end",
    ) -> None:
        """Initialize the call tracking middleware.

        Args:
            thread_limit: Maximum number of model calls allowed per thread.

                `None` means no limit.
            run_limit: Maximum number of model calls allowed per run.

                `None` means no limit.
            exit_behavior: What to do when limits are exceeded.

                - `'end'`: Jump to the end of the agent execution and
                    inject an artificial AI message indicating that the limit was
                    exceeded.
                - `'error'`: Raise a `ModelCallLimitExceededError`

        Raises:
            ValueError: If both limits are `None` or if `exit_behavior` is invalid.
        """
        super().__init__()

        if thread_limit is None and run_limit is None:
            msg = "At least one limit must be specified (thread_limit or run_limit)"
            raise ValueError(msg)

        if exit_behavior not in {"end", "error"}:
            msg = f"Invalid exit_behavior: {exit_behavior}. Must be 'end' or 'error'"
            raise ValueError(msg)

        self.thread_limit = thread_limit
        self.run_limit = run_limit
        self.exit_behavior = exit_behavior