langchain_community.chat_message_histories.dynamodb
.DynamoDBChatMessageHistory¶
- class langchain_community.chat_message_histories.dynamodb.DynamoDBChatMessageHistory(table_name: str, session_id: str, endpoint_url: Optional[str] = None, primary_key_name: str = 'SessionId', key: Optional[Dict[str, str]] = None, boto3_session: Optional[Session] = None, kms_key_id: Optional[str] = None, ttl: Optional[int] = None, ttl_key_name: str = 'expireAt', history_size: Optional[int] = None, history_messages_key: Optional[str] = 'History')[source]¶
Chat message history that stores history in AWS DynamoDB.
This class expects that a DynamoDB table exists with name table_name
- Parameters
table_name (str) – name of the DynamoDB table
session_id (str) – arbitrary key that is used to store the messages of a single chat session.
endpoint_url (Optional[str]) – URL of the AWS endpoint to connect to. This argument is optional and useful for test purposes, like using Localstack. If you plan to use AWS cloud service, you normally don’t have to worry about setting the endpoint_url.
primary_key_name (str) – name of the primary key of the DynamoDB table. This argument is optional, defaulting to “SessionId”.
key (Optional[Dict[str, str]]) – an optional dictionary with a custom primary and secondary key. This argument is optional, but useful when using composite dynamodb keys, or isolating records based off of application details such as a user id. This may also contain global and local secondary index keys.
kms_key_id (Optional[str]) – an optional AWS KMS Key ID, AWS KMS Key ARN, or AWS KMS Alias for client-side encryption
ttl (Optional[int]) – Optional Time-to-live (TTL) in seconds. Allows you to define a per-item expiration timestamp that indicates when an item can be deleted from the table. DynamoDB handles deletion of expired items without consuming write throughput. To enable this feature on the table, follow the [AWS DynamoDB documentation](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/time-to-live-ttl-how-to.html)
history_size (Optional[int]) – Maximum number of messages to store. If None then there is no limit. If not None then only the latest history_size messages are stored.
history_messages_key (Optional[str]) – Key for the chat history where the messages are stored and updated
boto3_session (Optional[Session]) –
ttl_key_name (str) –
Attributes
messages
Retrieve the messages from DynamoDB
Methods
__init__
(table_name, session_id[, ...])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 DynamoDB
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
()Clear session memory from DynamoDB
- __init__(table_name: str, session_id: str, endpoint_url: Optional[str] = None, primary_key_name: str = 'SessionId', key: Optional[Dict[str, str]] = None, boto3_session: Optional[Session] = None, kms_key_id: Optional[str] = None, ttl: Optional[int] = None, ttl_key_name: str = 'expireAt', history_size: Optional[int] = None, history_messages_key: Optional[str] = 'History')[source]¶
- Parameters
table_name (str) –
session_id (str) –
endpoint_url (Optional[str]) –
primary_key_name (str) –
key (Optional[Dict[str, str]]) –
boto3_session (Optional[Session]) –
kms_key_id (Optional[str]) –
ttl (Optional[int]) –
ttl_key_name (str) –
history_size (Optional[int]) –
history_messages_key (Optional[str]) –
- 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 DynamoDB
- 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]