_exit_history() — langchain Function Reference

Architecture documentation for the _exit_history() function in history.py from the langchain codebase.

Function python LangChainCore Runnables calls 2

Entity Profile

LangChainCore→ Runnables→ _exit_history() — langchain Function Reference

Dependency Diagram

graph TD
  9297f3bd_05a3_097d_3fa4_b9184b373e13["_exit_history()"]
  f9cb8198_4568_d401_f003_82c579cfa18f["RunnableWithMessageHistory"]
  9297f3bd_05a3_097d_3fa4_b9184b373e13 -->|defined in| f9cb8198_4568_d401_f003_82c579cfa18f
  1978b1f4_7f00_d1ef_ed53_b27b8e0a8df8["_get_input_messages()"]
  9297f3bd_05a3_097d_3fa4_b9184b373e13 -->|calls| 1978b1f4_7f00_d1ef_ed53_b27b8e0a8df8
  293dcfbd_674c_d56d_4708_39019a6881d5["_get_output_messages()"]
  9297f3bd_05a3_097d_3fa4_b9184b373e13 -->|calls| 293dcfbd_674c_d56d_4708_39019a6881d5
  style 9297f3bd_05a3_097d_3fa4_b9184b373e13 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/runnables/history.py lines 538–553

    def _exit_history(self, run: Run, config: RunnableConfig) -> None:
        hist: BaseChatMessageHistory = config["configurable"]["message_history"]

        # Get the input messages
        inputs = load(run.inputs, allowed_objects="all")
        input_messages = self._get_input_messages(inputs)
        # If historic messages were prepended to the input messages, remove them to
        # avoid adding duplicate messages to history.
        if not self.history_messages_key:
            historic_messages = config["configurable"]["message_history"].messages
            input_messages = input_messages[len(historic_messages) :]

        # Get the output messages
        output_val = load(run.outputs, allowed_objects="all")
        output_messages = self._get_output_messages(output_val)
        hist.add_messages(input_messages + output_messages)