langchain.memory.chat_message_histories.momento.MomentoChatMessageHistory¶
class langchain.memory.chat_message_histories.momento.MomentoChatMessageHistory(session_id: str, cache_client: momento.CacheClient, cache_name: str, *, key_prefix: str = 'message_store:', ttl: Optional[timedelta] = None, ensure_cache_exists: bool = True)[source]¶
Chat message history cache that uses Momento as a backend.
See https://gomomento.com/
Instantiate a chat message history cache that uses Momento as a backend.
Note: to instantiate the cache client passed to MomentoChatMessageHistory,
you must have a Momento account at https://gomomento.com/.
Parameters
session_id (str) – The session ID to use for this chat session.
cache_client (CacheClient) – The Momento cache client.
cache_name (str) – The name of the cache to use to store the messages.
key_prefix (str, optional) – The prefix to apply to the cache key.
Defaults to “message_store:”.
ttl (Optional[timedelta], optional) – The TTL to use for the messages.
Defaults to None, ie the default TTL of the cache will be used.
ensure_cache_exists (bool, optional) – Create the cache if it doesn’t exist.
Defaults to True.
Raises
ImportError – Momento python package is not installed.
TypeError – cache_client is not of type momento.CacheClientObject
Attributes
messages
Retrieve the messages from Momento.
Methods
__init__(session_id, cache_client, cache_name, *)
Instantiate a chat message history cache that uses Momento as a backend.
add_ai_message(message)
Convenience method for adding an AI message string to the store.
add_message(message)
Store a message in the cache.