Chat History API

Persistent conversation storage.

langchain_cockroachdb.chat_message_histories.CockroachDBChatMessageHistory

Bases: BaseChatMessageHistory

Chat message history stored in CockroachDB.

Pass a shared CockroachDBEngine to reuse one connection pool and one retry policy across sessions. With only a connection string the history opens and owns its own engine, which close() or aclose() releases.

Messages get ids generated here and are written with ON CONFLICT DO NOTHING, so retrying after an ambiguous result never duplicates them.

messages property

Get all messages for this session.

Note: BaseChatMessageHistory declares messages as a writable attribute, but we expose it as a read-only property (matching langchain-postgres).

__del__()

Release an owned engine that was never closed, without blocking.

__init__(session_id, connection_string=None, engine=None, table_name='message_store', schema='public', *, retry_policy=None)

Initialize chat message history.

Parameters:

Name	Type	Description	Default
session_id	str	Unique session/thread identifier	required
connection_string	str | None	Database connection string, used when no engine is given	None
engine	CockroachDBEngine | AsyncEngine | None	Shared CockroachDBEngine (recommended) or a SQLAlchemy AsyncEngine	None
table_name	str	Table name for messages	'message_store'
schema	str	Database schema	'public'
retry_policy	RetryPolicy | None	How operations retry (default: the engine's policy)	None

aadd_message(message) async

Add a message (async).

aadd_messages(messages) async

Add messages atomically, in order (async).

aclear() async

Clear messages (async).

aclose() async

Close the engine if this history created it.

acreate_table_if_not_exists() async

Create the message table and its session index if they do not exist.

add_message(message)

Add a message to the session.

add_messages(messages)

Add messages atomically, in order.

aget_messages() async

Get all messages for this session (async).

clear()

Clear all messages for this session.

close()

Close the engine if this history created it (sync).

create_table_if_not_exists()

Create table (sync).

Parameters

Parameter	Type	Default	Description
session_id	str	Required	Session or thread identifier
connection_string	str	None	Database connection string (if engine not provided)
engine	CockroachDBEngine	None	Shared engine instance
table_name	str	"message_store"	Table name for messages
retry_policy	RetryPolicy	None	Retry policy (inherits from engine if not set)

Key Methods

Method	Description
add_user_message()	Add user message
add_ai_message()	Add AI response
add_message()	Add any message type
add_messages()	Add multiple messages atomically
clear()	Clear session history
messages	Get all messages
acreate_table_if_not_exists()	Create table if needed (async)
create_table_if_not_exists()	Create table if needed (sync)

Examples

See Chat History Guide for comprehensive examples.