langchain_community.chat_message_histories.redis.RedisChatMessageHistory¶

class langchain_community.chat_message_histories.redis.RedisChatMessageHistory(session_id: str, url: str = 'redis://localhost:6379/0', key_prefix: str = 'message_store:', ttl: Optional[int] = None)[source]¶

Chat message history stored in a Redis database.

Setup:

Install redis python package.

pip install redis
Instantiate:

from langchain_community.chat_message_histories import RedisChatMessageHistory

history = RedisChatMessageHistory(

session_id = “your-session-id”, url=”redis://your-host:your-port:your-database”, # redis://localhost:6379/0

)

Add and retrieve messages:
# Add single message
history.add_message(message)

# Add batch messages
history.add_messages([message1, message2, message3, ...])

# Add human message
history.add_user_message(human_message)

# Add ai message
history.add_ai_message(ai_message)

# Retrieve messages
messages = history.messages

Initialize with a RedisChatMessageHistory instance.

Parameters

  • session_id (str) – str The ID for single chat session. Used to form keys with key_prefix.

  • url (str) – Optional[str] String parameter configuration for connecting to the redis.

  • key_prefix (str) – Optional[str] The prefix of the key, combined with session id to form the key.

  • ttl (Optional[int]) – Optional[int] Set the expiration time of key, the unit is seconds.

Attributes

key

Construct the record key to use

messages

Retrieve the messages from Redis

Methods

__init__(session_id[, url, key_prefix, ttl])

Initialize with a RedisChatMessageHistory instance.

aadd_messages(messages)

Async add a list of messages.

aclear()

Async remove all messages from the store

add_ai_message(message)

Convenience method for adding an AI message string to the store.

add_message(message)

Append the message to the record in Redis

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 Redis
__init__(session_id: str, url: str = 'redis://localhost:6379/0', key_prefix: str = 'message_store:', ttl: Optional[int] = None)[source]¶

Initialize with a RedisChatMessageHistory instance.

Parameters

  • session_id (str) – str The ID for single chat session. Used to form keys with key_prefix.

  • url (str) – Optional[str] String parameter configuration for connecting to the redis.

  • key_prefix (str) – Optional[str] The prefix of the key, combined with session id to form the key.

  • ttl (Optional[int]) – Optional[int] Set the expiration time of key, the unit is seconds.

async aadd_messages(messages: Sequence[BaseMessage]) → None¶

Async add a list of messages.

Parameters

messages (Sequence[BaseMessage]) – A sequence of BaseMessage objects to store.

Return type

None

async aclear() → None¶

Async 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]¶

Append the message to the record in Redis

Parameters

message (BaseMessage) –

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 sequence 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 to the store.

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 Redis

Return type

None

Examples using RedisChatMessageHistory¶