Memory components in Langflow

This Langflow feature is currently in public preview. Development is ongoing, and the features and functionality are subject to change. Langflow, and the use of such, is subject to the DataStax Preview Terms.

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.

astra db chat memory rounded

AstraDB Chat Memory Component

This component creates an AstraDBChatMessageHistory instance, which allows for storing and retrieving chat messages using Astra DB.

Parameters

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.

Component code

astra_db.py
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Cassandra Chat Memory Component

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

Parameters

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.

Component code

cassandra.py
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Mem0 Chat Memory

The Mem0 Chat Memory component retrieves and stores chat messages using Mem0 memory storage.

Parameters

Inputs
Name Display Name Info

mem0_config

Mem0 Configuration

Configuration dictionary for initializing Mem0 memory instance.

ingest_message

Message to Ingest

The message content to be ingested into Mem0 memory.

existing_memory

Existing Memory Instance

Optional existing Mem0 memory instance.

user_id

User ID

Identifier for the user associated with the messages.

search_query

Search Query

Input text for searching related memories in Mem0.

mem0_api_key

Mem0 API Key

API key for Mem0 platform (leave empty to use the local version).

metadata

Metadata

Additional metadata to associate with the ingested message.

openai_api_key

OpenAI API Key

API key for OpenAI (required if using OpenAI embeddings without a provided configuration).

Outputs
Name Display Name Info

memory

Mem0 Memory

The resulting Mem0 Memory object after ingesting data.

search_results

Search Results

The search results from querying Mem0 memory.

Component code

mem0_chat_memory.py
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Redis Chat Memory

The Redis Chat Memory component retrieves and stores chat messages using Redis.

Parameters

Inputs
Name Display Name Info

host

hostname

The IP address or hostname of the Redis server. This is required to establish a connection to the Redis instance.

port

port

The port number on which the Redis server is listening. The default Redis port is 6379.

database

database

The Redis database number to use. Redis supports multiple databases, identified by integers. The default is usually 0.

username

Username

The username for authenticating with the Redis server. This is used if Redis is configured with access control lists (ACLs).

password

Password

The password associated with the username for Redis authentication. This should be kept secure and not exposed in plain text.

key_prefix

Key prefix

A string prefix added to all keys stored in Redis for this chat memory. This helps in organizing and isolating keys for different applications or purposes within the same Redis instance.

session_id

Session ID

A unique identifier for the chat session. This is used to retrieve and store messages specific to a particular conversation or user session.

Outputs
Name Display Name Info

message_history

Message History

A RedisChatMessageHistory object that can be used with memory components like BufferMemory in Langchain. This object allows for storing and retrieving chat messages from Redis, providing persistence across chat sessions.

Component code

redis.py
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Zep Chat Memory Component

This component is in Legacy. Legacy components can be used in flows, but may not work due to Langflow core updates. Instead, use the AstraDB Chat Memory component.

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

Parameters

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. Use api/v1`for the Zep Community Edition and `api/v2 for the Zep Cloud version.

session_id

MessageText

Unique identifier for the chat session. Optional.

Outputs

Name

Type

Description

message_history

BaseChatMessageHistory

An instance of ZepChatMessageHistory for the session.

Component code

zep.py
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