langgraph-state-management

Follow this workflow when designing or modifying state for a LangGraph application:

For convenience, subclass the built-in MessagesState (includes messages with addmessages reducer):

Choose the pattern matching the application type. See references/schema-patterns.md for complete examples with both Python and TypeScript.

Design state schemas, implement reducers, configure persistence, and debug state issues for LangGraph applications. Use when users want to (1) design or define state schemas for LangGraph graphs, (2) implement reducer functions for state accumulation, (3) configure persistence with checkpointers (InMemorySaver/MemorySaver, SqliteSaver, PostgresSaver), (4) debug state update issues or unexpected state behavior, (5) migrate state schemas between versions, (6) validate state schema structure, (7) choose between TypedDict and MessagesState patterns, (8) implement custom reducers for lists, dicts, or sets, (9) use the Overwrite type to bypass reducers, (10) set up thread-based persistence for multi-turn conversations, or (11) inspect checkpoints for debugging. Source: lubu-labs/langchain-agent-skills.