langchain_community.chat_message_histories.cassandra.CassandraChatMessageHistory¶

class langchain_community.chat_message_histories.cassandra.CassandraChatMessageHistory(session_id: str, session: Optional[Session] = None, keyspace: Optional[str] = None, table_name: str = 'message_store', ttl_seconds: Optional[int] = None)[source]¶

Chat message history that stores history in Cassandra.

Parameters

  • session_id (str) – arbitrary key that is used to store the messages of a single chat session.

  • session (Optional[Session]) – Cassandra driver session. If not provided, it is resolved from cassio.

  • keyspace (Optional[str]) – Cassandra key space. If not provided, it is resolved from cassio.

  • table_name (str) – name of the table to use.

  • ttl_seconds (Optional[int]) – time-to-live (seconds) for automatic expiration of stored entries. None (default) for no expiration.

Attributes

messages

Retrieve all session messages from DB

Methods

__init__(session_id[, session, keyspace, ...])

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)

Write a message to the table

add_messages(messages)

Add a list of messages.

add_user_message(message)

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

aget_messages()

Async version of getting messages.

clear()

Clear session memory from DB
__init__(session_id: str, session: Optional[Session] = None, keyspace: Optional[str] = None, table_name: str = 'message_store', ttl_seconds: Optional[int] = None) → None[source]¶
Parameters

  • session_id (str) –

  • session (Optional[Session]) –

  • keyspace (Optional[str]) –

  • table_name (str) –

  • ttl_seconds (Optional[int]) –

Return type

None

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]¶

Write a message to the table

Parameters

message (BaseMessage) – A message to write.

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]¶

Clear session memory from DB

Return type

None

Examples using CassandraChatMessageHistory¶