langgraph 0.2.12

Summary of Changes

• Improved error messages for channel operations, now including the channel key in error messages for easier debugging #1437
• Fixed automatic type detection for node functions, improving schema detection reliability #1332
• Simplified internal interrupt handling for more consistent behavior #1436
• Fixed async task handling in AsyncBackgroundExecutor for better exception management #1442
• Removed unused method from PregelLoop #1440

Detailed Changes

langgraph.channels.base.BaseChannel

• Added key property to track which channel key a channel instance is associated with #1437
• Added from_checkpoint_named and afrom_checkpoint_named methods to preserve channel keys when restoring from checkpoints #1437
• Updated type annotations from Generator to Iterator and AsyncGenerator to AsyncIterator for better type clarity #1437

langgraph.channels.* (Multiple Channel Implementations)

• Enhanced error messages in all channel implementations to include the channel key in error messages #1437
• Improved guidance in error messages for LastValue, EphemeralValue, and UntrackedValue to suggest alternatives (e.g., using Annotated keys or guard=False) #1437

langgraph.graph.state.StateGraph

• Fixed automatic input type detection logic to correctly identify function parameter types, using inspect.signature for more reliable parameter name detection #1332
• Added handling for additional exceptions (StopIteration) when introspecting function parameters #1332
• Removed redundant support_multiple_edges setting logic #1437
• Updated channel creation logic to set the channel key, improving error messages #1437

langgraph.graph.graph.Graph

• Improved validation error message in add_edge method to clarify when to use StateGraph with Annotated state keys #1437

langgraph.constants.Interrupt and langgraph.errors.GraphInterrupt

• Simplified the Interrupt data class to focus on value rather than "when" it occurred #1436
• Simplified GraphInterrupt to accept an optional empty sequence of interrupts #1436

langgraph.pregel.executor.AsyncBackgroundExecutor

• Fixed async task handling to properly manage exceptions and task completion #1442
• Improved how GraphInterrupt exceptions are handled, distinguishing them from other exceptions #1442

langgraph.pregel.loop.PregelLoop

• Simplified interrupt handling to be more consistent and straightforward #1436
• Removed unused mark_tasks_scheduled method #1440
• Added a check to prevent processing empty writes #1436