- Replace get_type_hints logic with much simpler implementation which only collects annotated keys (not the annotations themselves)
- Cache annotations in a WeakKeyDictionary
- Now defaulting to False, ie. saving only the final checkpoint
- All features other than time travel into an intermediate step are supported by checkpoint_during=False so this is a better default for almost all use cases
- This has been superseded by saving the individual writes of each task through put_writes()
- Removing this speeds up checkpoint operations as it was duplicating data saved elsewhere already
- Instead store sends in a Topic channel, removing the need to fetch sends as writes against the parent checkpoint
- Remove deprecated/unused functions in langgraph-checkpoint (will require bumping min range for langgraph-checkpoint in langgraph lib)
- Implement migration of old pending sends in langgraph-checkpoint-postgres
- Ensure parent config of `checkpoint_during=False` checkpoints always points to checkpoints that were also saved
- Now all tests fully migrated to more recent sync_checkpointer and async_checkpointer fixtures for parametrising on checkpointer
- Use sync/async_store fixtures where tests used only in memory store
- Remove unused "should snapshot" check for older versions of langchain core no longer tested against
- This keeps the existing API for accessing IsLastValue, RemainingSteps, but simplifies the internal implementation
- This lets us remove ChannelsManager completely, which no longer needs to be a context manager, now replaced w function channels_from_checkpoint
- Managed values are now simple functions that return a value given a PregelScratchpad, which will be easier to implement in distributed runner
- Both have been deprecated long ago, have not been present in docs for quite a while
- Removing these lets us delete some code paths that were dedicated to this, easing work on distributed runner
