📰 Story

langgraph==1.2.0a6

langgraph v1.2 (alpha) This release adds finer-grained control over node execution — timeouts, error recovery, and graceful shutdown — a new channel type that cuts checkpoint overhead for long-running threads, and a new content-block-centric streaming API (v3) with typed, per-channel projections. DeltaChannel (beta) A new channel type that stores only the incremental delta at each step rather than re-serializing the full accumulated value. Most useful for channels that grow large over time — for example, a message list in a long-running thread. Without it, the full message list is written into every checkpoint; with DeltaChannel , only the new messages from each step are stored. Use snapshot_frequency=K to write a full snapshot every K steps and bound read latency: from typing import Annotated , Sequence from typing_extensions import TypedDict from langgraph . channels import DeltaChannel # batch reducer: receives the current value and all writes from the superstep at once def list_reducer ( messages : list [ str ], writes : Sequence [ list [ str ]]) -> list [ str ]: return [ * messages , * ( item for write in writes for item in write )] class State ( TypedDict ): messages : Annotated [ list [ str ], DeltaChannel ( list_reducer , snapshot_frequency = 5 )] Read the DeltaChannel docs → Per-node timeouts Pass timeout= to add_node to cap how long a single attempt may run. You can set a hard wall-clock limit ( run_timeout ), an idle limit that resets on progress ( idle_timeout ),