base

Protocol for serialization and deserialization of objects.

• dumps_typed: Serialize an object to a tuple (type, bytes).
• loads_typed: Deserialize an object from a tuple (type, bytes).

Valid implementations include the pickle, json and orjson modules.

Serializer that encrypts and decrypts data using an encryption protocol.

Serializer that uses ormsgpack, with optional fallbacks.

Metadata associated with a checkpoint.

State snapshot at a given point in time.

A tuple containing a checkpoint and its associated data.

Base class for creating a graph checkpointer.

Checkpointers allow LangGraph agents to persist their state within and across multiple interactions.

When a checkpointer is configured, you should pass a thread_id in the config when invoking the graph:

config = {"configurable": {"thread_id": "my-thread"}}
graph.invoke(inputs, config)

The thread_id is the primary key used to store and retrieve checkpoints. Without it, the checkpointer cannot save state, resume from interrupts, or enable time-travel debugging.

How you choose thread_id depends on your use case:

• Single-shot workflows: Use a unique ID (e.g., uuid4) for each run when executions are independent.
• Conversational memory: Reuse the same thread_id across invocations to accumulate state (e.g., chat history) within a conversation.

Raised when attempting to get the value of a channel that hasn't been updated for the first time yet.