langchain-ai/langgraph · error · InvalidNamespaceError

Invalid namespace label '{label}' found in {namespace}. Name

Error message

Invalid namespace label '{label}' found in {namespace}. Namespace labels must be strings, but got {type(label).__name__}.

What it means

Error "Invalid namespace label '{label}' found in {namespace}. Namespace labels must be strings, but got {type(label).__name__}." thrown in langchain-ai/langgraph.

Source

Thrown at libs/checkpoint/langgraph/checkpoint/store/base/__init__.py:1268

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/checkpoint/langgraph/checkpoint/store/base/__init__.py:1268 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of langchain-ai/langgraph@38031739e5 (2026-08-26). Data as JSON: /api/errors/60dd452f9dbb8e8c. Report an issue: GitHub.