RemoteAgent

Stream agent execution, yielding tuples matching Pregel's format.

Delegates to RemoteGraph.astream (which handles messages-tuple negotiation, SSE routing, and namespace parsing) and converts the raw message dicts into LangChain message objects for the adapter.

Get the current state of a thread.

Returns None when the thread does not exist on the server (404). All other errors (network, auth, 500) are logged at WARNING and re-raised so callers can handle them.

Unlike astream, message values are not deserialized; callers may receive serialized message dicts in values["messages"] from the server.

Update the state of a thread.

Exceptions from the underlying graph (server/network errors) are logged at WARNING level and then re-raised so callers can handle them.

Ensure the remote thread record exists before mutating state.

In the LangGraph dev server, checkpoint persistence and HTTP thread registration are separate. After a server restart, a thread may still have checkpointed state on disk while POST /threads/{id}/state returns 404 because the server has not yet materialized that thread in its live store.

This method performs the idempotent HTTP-side registration with if_exists='do_nothing' so callers that recovered state from persistence can safely follow up with aupdate_state.

Return self (config is passed per-call, not stored).