Error2 reports
Fix NotImplementedError
in LangGraph
✅ Solution
The "NotImplementedError" in LangGraph commonly arises when a required method or function within a custom class or component (like a custom Tool or Agent) is not defined. To fix this, identify the missing method (usually indicated in the error traceback) and implement its functionality within your custom class. Ensure your custom components align with the expected interface for proper execution within the LangGraph framework.
Related Issues
Real GitHub issues where developers encountered this error:
Timeline
First reported:Aug 26, 2025
Last reported:Nov 22, 2025