langchain_core.chat_history.BaseChatMessageHistory

class langchain_core.chat_history.BaseChatMessageHistory

Abstract base class for storing chat message history.

See ChatMessageHistory for default implementation.

Example

class FileChatMessageHistory(BaseChatMessageHistory):
    storage_path:  str
    session_id: str

   @property
   def messages(self):
       with open(os.path.join(storage_path, session_id), 'r:utf-8') as f:
           messages = json.loads(f.read())
        return messages_from_dict(messages)

   def add_message(self, message: BaseMessage) -> None:
       messages = self.messages.append(_message_to_dict(message))
       with open(os.path.join(storage_path, session_id), 'w') as f:
           json.dump(f, messages)

   def clear(self):
       with open(os.path.join(storage_path, session_id), 'w') as f:
           f.write("[]")

Attributes

messages

A list of Messages stored in-memory.

Methods

__init__()
add_ai_message(message)	Convenience method for adding an AI message string to the store.
add_message(message)	Add a Message object to the store.
add_user_message(message)	Convenience method for adding a human message string to the store.
clear()	Remove all messages from the store

__init__()

add_ai_message(message: Union[AIMessage, str]) → None

Convenience method for adding an AI message string to the store.

Parameters

message – The AI message to add.

abstract add_message(message: BaseMessage) → None

Add a Message object to the store.

Parameters

message – A BaseMessage object to store.

add_user_message(message: Union[HumanMessage, str]) → None

Convenience method for adding a human message string to the store.

Parameters

message – The human message to add

abstract clear() → None

Remove all messages from the store