langgraph_agent_toolkit.core.memory.coordinated_saver module

Keep checkpoint operations on the connection that owns the conversation lock.

class langgraph_agent_toolkit.core.memory.coordinated_saver.CoordinatedPostgresSaver(conn, pipe=None, serde=None)

Bases: AsyncPostgresSaver

Use the pool outside a run, and the locked session during a run.

Override the upstream cursor hook so reads, writes, and deletion share the same session. A disconnected session cannot write through a replacement connection after another worker acquires the conversation lock.

Parameters:

serde (SerializerProtocol)

__init__(conn, pipe=None, serde=None)

async setup()

Serialize schema changes when several workers start together.

Return type:

None

async alist(config, *, filter=None, before=None, limit=None)

Release the database cursor before the caller receives a checkpoint.

Parameters:

• config (RunnableConfig | None)

• filter (dict[str, Any] | None)

• before (RunnableConfig | None)

• limit (int | None)

Return type:

AsyncIterator[CheckpointTuple]