langchain_community.chat_message_histories.momento
.MomentoChatMessageHistory¶
- class langchain_community.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.
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.
aadd_messages
(messages)Add a list of messages.
aclear
()Remove all messages from the store
add_ai_message
(message)Convenience method for adding an AI message string to the store.
add_message
(message)Store a message in the cache.
add_messages
(messages)Add a list of messages.
add_user_message
(message)Convenience method for adding a human message string to the store.
Async version of getting messages.
clear
()Remove the session's messages from the cache.
from_client_params
(session_id, cache_name, ...)Construct cache from CacheClient parameters.
- __init__(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]¶
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
- async aadd_messages(messages: Sequence[BaseMessage]) None ¶
Add a list of messages.
- Parameters
messages (Sequence[BaseMessage]) – A list of BaseMessage objects to store.
- Return type
None
- async aclear() None ¶
Remove all messages from the store
- Return type
None
- add_ai_message(message: Union[AIMessage, str]) None ¶
Convenience method for adding an AI message string to the store.
Please note that this is a convenience method. Code should favor the bulk add_messages interface instead to save on round-trips to the underlying persistence layer.
This method may be deprecated in a future release.
- Parameters
message (Union[AIMessage, str]) – The AI message to add.
- Return type
None
- add_message(message: BaseMessage) None [source]¶
Store a message in the cache.
- Parameters
message (BaseMessage) – The message object to store.
- Raises
SdkException – Momento service or network error.
Exception – Unexpected response.
- Return type
None
- add_messages(messages: Sequence[BaseMessage]) None ¶
Add a list of messages.
Implementations should over-ride this method to handle bulk addition of messages in an efficient manner to avoid unnecessary round-trips to the underlying store.
- Parameters
messages (Sequence[BaseMessage]) – A list of BaseMessage objects to store.
- Return type
None
- add_user_message(message: Union[HumanMessage, str]) None ¶
Convenience method for adding a human message string to the store.
Please note that this is a convenience method. Code should favor the bulk add_messages interface instead to save on round-trips to the underlying persistence layer.
This method may be deprecated in a future release.
- Parameters
message (Union[HumanMessage, str]) – The human message to add
- Return type
None
- async aget_messages() List[BaseMessage] ¶
Async version of getting messages.
Can over-ride this method to provide an efficient async implementation.
In general, fetching messages may involve IO to the underlying persistence layer.
- Return type
List[BaseMessage]
- clear() None [source]¶
Remove the session’s messages from the cache.
- Raises
SdkException – Momento service or network error.
Exception – Unexpected response.
- Return type
None
- classmethod from_client_params(session_id: str, cache_name: str, ttl: timedelta, *, configuration: Optional[momento.config.Configuration] = None, api_key: Optional[str] = None, auth_token: Optional[str] = None, **kwargs: Any) MomentoChatMessageHistory [source]¶
Construct cache from CacheClient parameters.
- Parameters
session_id (str) –
cache_name (str) –
ttl (timedelta) –
configuration (Optional[momento.config.Configuration]) –
api_key (Optional[str]) –
auth_token (Optional[str]) –
kwargs (Any) –
- Return type