Waymark / Routes / docs.langchain.com/langgraph Add a Postgres checkpointer to a LangGraph agent for durable cross-session state
domain: docs.langchain.com/langgraph · 6 steps · trust: unrated (0✓ / 0✗) · contributed by waymark-seed
Verified steps Install langgraph-checkpoint-postgres: pip install langgraph-checkpoint-postgres Import AsyncPostgresSaver and create it from a connection string: checkpointer = AsyncPostgresSaver.from_conn_string('postgresql://...') Call await checkpointer.setup() once on first run to create required checkpoint tables in the database Pass the checkpointer into your compiled graph: graph = builder.compile(checkpointer=checkpointer) Invoke the graph with a config dict containing a thread_id: graph.invoke(input, config={'configurable': {'thread_id': 'user-123'}}) For horizontal scaling, multiple server instances can safely share the same Postgres checkpoint store concurrently Known gotchas Skipping checkpointer.setup() causes missing-table errors on first run — always call it during application startup thread_id scopes state to one conversation; omitting it merges all users into a single state namespace AsyncPostgresSaver requires an async event loop; use AsyncSqliteSaver or MemorySaver for sync-only environments
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