Memory components in Langflow

Memory components store and retrieve chat messages by session_id.

They are distinct from vector store components, because they are built specifically for storing and retrieving chat messages from external databases.

Memory components provide access to their respective external databases as memory. This allows Large Language Models (LLMs) or agents to access external memory for persistence and context retention.

Use a memory component in a flow

This example flow stores and retrieves chat history from an Astra DB Chat Memory component with Store Message and Chat Memory components.

The Store Message helper component stores chat memories as Data objects, and the Message History helper component retrieves chat messages as Data objects or strings.

AstraDBChatMemory Component

This component creates an AstraDBChatMessageHistory instance, which stores and retrieves chat messages using Astra DB, a cloud-native database service.

Inputs

Name	Type	Description
collection_name	String	Name of the Astra DB collection for storing messages. Required.
token	SecretString	Authentication token for Astra DB access. Required.
api_endpoint	SecretString	API endpoint URL for the Astra DB service. Required.
namespace	String	Optional namespace within Astra DB for the collection.
session_id	MessageText	Chat session ID. Uses current session ID if not provided.

Outputs

Name	Type	Description
message_history	BaseChatMessageHistory	An instance of AstraDBChatMessageHistory for the session.

CassandraChatMemory Component

This component creates a CassandraChatMessageHistory instance, enabling storage and retrieval of chat messages using Apache Cassandra or DataStax Astra DB.

Inputs

Name	Type	Description
database_ref	MessageText	Contact points for Cassandra or Astra DB database ID. Required.
username	MessageText	Username for Cassandra (leave empty for Astra DB).
token	SecretString	Password for Cassandra or token for Astra DB. Required.
keyspace	MessageText	Keyspace in Cassandra or namespace in Astra DB. Required.
table_name	MessageText	Name of the table or collection for storing messages. Required.
session_id	MessageText	Unique identifier for the chat session. Optional.
cluster_kwargs	Dictionary	Additional keyword arguments for Cassandra cluster configuration. Optional.

Outputs

Name	Type	Description
message_history	BaseChatMessageHistory	An instance of CassandraChatMessageHistory for the session.

ZepChatMemory Component

This component creates a ZepChatMessageHistory instance, enabling storage and retrieval of chat messages using Zep, a memory server for Large Language Models (LLMs).

Inputs

Name	Type	Description
url	MessageText	URL of the Zep instance. Required.
api_key	SecretString	API Key for authentication with the Zep instance.
api_base_path	Dropdown	API version to use. Options: "api/v1" or "api/v2".
session_id	MessageText	Unique identifier for the chat session. Optional.

Outputs

Name	Type	Description
message_history	BaseChatMessageHistory	An instance of ZepChatMessageHistory for the session.