LangGraph for Stateful Agent Workflows
Practical LangGraph production guides for state isolation, checkpoints, update-state failures, subgraphs, supervision, human approval, retries and observability.
Decision Paths
Start from the decision you need to make now, then enter the deeper topic map.
Define state and thread boundaries first
Separate user, session and run state before choosing a checkpointer or persistence backend.
Pause, approve and resume
Use interrupt and resume with durable state when a human must authorize the next action.
Recover from failures and timeouts
Handle retry, timeout, checkpoint timing and idempotency without blindly restarting the graph.
Operate and trace in production
Make state transitions, tool calls and failure paths observable before production rollout.
Primary Paths
All AI Engineering
Browse the complete reviewed English AI engineering library.
Checkpoint ZoneInfo / DST One-Hour Shift
Reproduce ZoneInfo and fold loss across checkpoint serialization and prevent DST wall-clock drift after resume.
First Checkpoint Crash / Accepted Run Loss
Reproduce the zero-checkpoint EmptyInputError window and design durable admission with an application-owned acceptance ledger.
LangGraph State Isolation
Design thread_id, session_id and user_id boundaries so concurrent Agent state does not leak across requests.
LangGraph Checkpointer
Choose Memory, SQLite or Redis persistence and understand checkpoint recovery and transaction boundaries.
Human-in-the-Loop Approval
Pause with interrupt(), persist approval state and resume safely after a human decision.
Error Recovery and Retry
Handle tool errors, timeouts, retries and recoverable graph failures without corrupting state.
Conditional Router Resume Skips Downstream
Reproduce resume behavior where a conditional router skips the expected downstream path and verify a safe recovery boundary.
Supervisor and Worker Handoffs
Coordinate multi-agent workers with explicit handoffs, state merging and failure routing.
