langgraph 0.2.4

Summary of Changes

• Improved documentation for Send class, clarifying its role in StateGraph conditional edges for flexible state management in workflows #1280
• Updated examples in prebuilt modules to use StateGraph instead of deprecated MessageGraph #1330
• Fixed several bugs in the Pregel engine related to task processing and checkpointing
• Improved error logging during task retries with more detailed exception information

Detailed Changes

langgraph.types.Send

• Enhanced documentation to better explain that Send can be used to dynamically invoke a node with a custom state at the next step
• Clarified that the sent state can differ from the core graph's state, allowing for flexible workflow management
• Added more descriptive example comments for "map-reduce" workflow patterns

langgraph.pregel.Pregel

• Modified state handling to properly manage Context channels by replacing them with LastValue channels when getting state
• Fixed how task names are extracted in state snapshots
• Improved checkpoint handling with better debug output generation
• Removed redundant input field from PregelTaskDescription to simplify task management

langgraph.pregel.retry

• Enhanced error logging during retries to include full exception information, making debugging easier