0.2.39

langgraph 0.2.39

Summary of Changes

• Added structured error codes and improved error messages with troubleshooting links (#2136)
• Added a new TAG_NOSTREAM constant to disable streaming for chat models (#2136)
• Fixed task handling issues in async and sync executors (#2136)
• Improved message filtering to respect TAG_HIDDEN and TAG_NOSTREAM tags (#2136)

Detailed Changes

langgraph.errors.ErrorCode

• Added a new ErrorCode enum with standardized error codes: GRAPH_RECURSION_LIMIT, INVALID_CONCURRENT_GRAPH_UPDATE, INVALID_GRAPH_NODE_RETURN_VALUE, and MULTIPLE_SUBGRAPHS (#2136)

langgraph.errors.create_error_message

• Added a helper function to create consistent error messages with links to troubleshooting documentation (#2136)

langgraph.constants.TAG_NOSTREAM

• Added a new constant TAG_NOSTREAM that can be used to disable streaming for chat models (#2136)

langgraph.pregel.executor.BackgroundExecutor

• Fixed a race condition in task handling by making a copy of the tasks dictionary before iterating and potentially modifying it (#2136)

langgraph.pregel.executor.AsyncBackgroundExecutor

• Fixed a race condition in task handling similar to the one in BackgroundExecutor (#2136)

langgraph.pregel.messages.StreamMessagesHandler

• Updated to respect TAG_NOSTREAM in on_chat_model_start and TAG_HIDDEN in on_chain_start to provide better control over what gets streamed (#2136)