StatefulAsyncCallbackHandler Class — langchain Architecture

Architecture documentation for the StatefulAsyncCallbackHandler class in test_async_callback_manager.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  4c7911c3_3a1d_f829_848f_5f683cc90bc9["StatefulAsyncCallbackHandler"]
  64513429_d001_87b1_5f19_cc17a3f3577b["AsyncCallbackHandler"]
  4c7911c3_3a1d_f829_848f_5f683cc90bc9 -->|extends| 64513429_d001_87b1_5f19_cc17a3f3577b
  f1a09d1e_2693_1456_76d6_3f34ca061a65["test_async_callback_manager.py"]
  4c7911c3_3a1d_f829_848f_5f683cc90bc9 -->|defined in| f1a09d1e_2693_1456_76d6_3f34ca061a65
  dfac0c64_07e2_1787_b14a_98ac7ded0851["__init__()"]
  4c7911c3_3a1d_f829_848f_5f683cc90bc9 -->|method| dfac0c64_07e2_1787_b14a_98ac7ded0851
  2916e273_7429_5c51_38d6_6936f07ce55b["on_llm_start()"]
  4c7911c3_3a1d_f829_848f_5f683cc90bc9 -->|method| 2916e273_7429_5c51_38d6_6936f07ce55b

Relationship Graph

Source Code

libs/core/tests/unit_tests/callbacks/test_async_callback_manager.py lines 96–127

    class StatefulAsyncCallbackHandler(AsyncCallbackHandler):
        def __init__(self, name: str, *, run_inline: bool = True):
            self.name = name
            self.run_inline = run_inline

        async def on_llm_start(
            self,
            serialized: dict[str, Any],
            prompts: list[str],
            *,
            run_id: UUID,
            parent_run_id: UUID | None = None,
            **kwargs: Any,
        ) -> None:
            if self.name == "StateModifier":
                current_counter = counter_var.get()
                counter_var.set(current_counter + 1)
                state = counter_var.get()
            elif self.name == "StateReader":
                state = counter_var.get()
            else:
                state = None

            shared_stack.append(state)

            await super().on_llm_start(
                serialized,
                prompts,
                run_id=run_id,
                parent_run_id=parent_run_id,
                **kwargs,
            )