Interface

Each checkpointer should conform to langgraph.checkpoint.base.BaseCheckpointSaver interface and must implement the following methods:

• .put - Store a checkpoint with its configuration and metadata.
• .put_writes - Store intermediate writes linked to a checkpoint (i.e. pending writes).
• .get_tuple - Fetch a checkpoint tuple using for a given configuration (thread_id and checkpoint_id).
• .list - List checkpoints that match a given configuration and filter criteria.
• .delete_thread() - Delete all checkpoints and writes associated with a thread.
• .get_next_version() - Generate the next version ID for a channel.

If the checkpointer will be used with asynchronous graph execution (i.e. executing the graph via .ainvoke, .astream, .abatch), checkpointer must implement asynchronous versions of the above methods (.aput, .aput_writes, .aget_tuple, .alist). Similarly, the checkpointer must implement .adelete_thread() if asynchronous thread cleanup is desired. The base class provides a default implementation of .get_next_version() that generates an integer sequence starting from 1, but this method should be overridden for custom versioning schemes.