_enter_history() — langchain Function Reference

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

Function python LangChainCore Runnables calls 1

Entity Profile

LangChainCore→ Runnables→ _enter_history() — langchain Function Reference

Dependency Diagram

graph TD
  5e360526_b3e5_8866_7151_d23f423330a1["_enter_history()"]
  f9cb8198_4568_d401_f003_82c579cfa18f["RunnableWithMessageHistory"]
  5e360526_b3e5_8866_7151_d23f423330a1 -->|defined in| f9cb8198_4568_d401_f003_82c579cfa18f
  1978b1f4_7f00_d1ef_ed53_b27b8e0a8df8["_get_input_messages()"]
  5e360526_b3e5_8866_7151_d23f423330a1 -->|calls| 1978b1f4_7f00_d1ef_ed53_b27b8e0a8df8
  style 5e360526_b3e5_8866_7151_d23f423330a1 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/runnables/history.py lines 512–522

    def _enter_history(self, value: Any, config: RunnableConfig) -> list[BaseMessage]:
        hist: BaseChatMessageHistory = config["configurable"]["message_history"]
        messages = hist.messages.copy()

        if not self.history_messages_key:
            # return all messages
            input_val = (
                value if not self.input_messages_key else value[self.input_messages_key]
            )
            messages += self._get_input_messages(input_val)
        return messages