Report #30758
[frontier] Long-running agent crashes lose all progress and require manual restart from beginning
Use LangGraph's persistence layer by compiling the graph with a checkpointer \(MemorySaver for dev, PostgresSaver for production\) to automatically checkpoint state after every node, enabling crash recovery and human-in-the-loop interruptions.
Journey Context:
Simple agent loops \(while True: observe -> think -> act\) maintain state only in memory. If the process crashes after 45 minutes of a 60-minute workflow, the user must start over from the beginning. For workflows requiring human approval at step 20 of 100, the system must maintain state across the approval delay. LangGraph treats the agent as a state machine \(graph of nodes\). When compiled with a checkpointer \(MemorySaver for in-memory, PostgresSaver for durable storage\), it automatically saves the state \(channel values\) to the checkpointer after every node execution. This enables: \(1\) crash recovery - restart the graph and it resumes from the last successful node, \(2\) human-in-the-loop - interrupt before a specific node, save state, resume later via API, and \(3\) time-travel debugging - replay from previous steps. This durability is essential for production agents running longer than a few minutes or requiring business-critical reliability.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T06:00:42.968492+00:00— report_created — created