Source code for langchain_community.chat_message_histories.file

import json
from pathlib import Path
from typing import List

from langchain_core.chat_history import (
    BaseChatMessageHistory,
)
from langchain_core.messages import BaseMessage, messages_from_dict, messages_to_dict


[docs]class FileChatMessageHistory(BaseChatMessageHistory): """Chat message history that stores history in a local file."""
[docs] def __init__(self, file_path: str) -> None: """Initialize the file path for the chat history. Args: file_path: The path to the local file to store the chat history. """ self.file_path = Path(file_path) if not self.file_path.exists(): self.file_path.touch() self.file_path.write_text(json.dumps([]))
@property def messages(self) -> List[BaseMessage]: # type: ignore """Retrieve the messages from the local file""" items = json.loads(self.file_path.read_text()) messages = messages_from_dict(items) return messages
[docs] def add_message(self, message: BaseMessage) -> None: """Append the message to the record in the local file""" messages = messages_to_dict(self.messages) messages.append(messages_to_dict([message])[0]) self.file_path.write_text(json.dumps(messages))
[docs] def clear(self) -> None: """Clear session memory from the local file""" self.file_path.write_text(json.dumps([]))