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6 posts tagged.
InvalidUpdateError: Can receive only one value per step means two parallel LangGraph nodes wrote the same state key with no reducer. Reproduce it in 15 lines and fix it the right way in Python and TypeScript (2026).
GraphRecursionError means you hit LangGraph's 25-superstep recursion limit. Raise it the right way, find the real infinite loop, and exit gracefully with RemainingSteps.
Make a LangGraph agent durable with a checkpointer: attach SqliteSaver in one line, crash the graph on purpose, and resume from disk without re-running the Claude call.
A runnable LangGraph human-in-the-loop tutorial for 2026: pause an agent mid-run with interrupt(), review the proposed action, then approve, edit, or reject it with Command(resume=...). Includes the checkpointer requirement and the re-run-from-the-top gotcha that breaks most tutorials.
A hands-on LangGraph tutorial for 2026: build the same tool-using AI agent two ways, with the five-line create_agent helper and as an explicit StateGraph you can customize. Fully runnable Python.
A runnable comparison of the Claude Agent SDK and LangGraph in 2026, with the same agent built in both and an honest decision matrix for when each wins.
