LangGraph State Management

State Design Workflow

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

1. Identify data requirements — What data flows through the graph?
2. Choose a schema pattern — Match the use case to a template
3. Define reducers — Decide how concurrent updates merge
4. Configure persistence — Select and set up a checkpointer
5. Validate and test — Run schema validation and reducer tests

Quick Start

Python — Minimal Chat State

from langgraph.graph import StateGraph, START, END, MessagesState
from langchain_core.messages import AIMessage