Direct answer
In 2026 this is an abstraction decision inside one stack, not a framework war. LangChain create_agent runs on the LangGraph runtime. Start there for standard tool-calling agents and middleware. Drop to LangGraph StateGraph when you need branching, durable checkpoints, human-in-the-loop interrupts, or multi-agent topologies. See LangChain and LangGraph.
When create_agent is enough
- Linear or lightly branched tool loops
- Middleware for PII redaction, summarization, or approvals
- RAG assembly with ecosystem connectors
When you need StateGraph
- Explicit conditional routing and loops
- Durable execution that must survive restarts
- Approval interrupts at arbitrary nodes
- Multi-agent coordination with typed shared state
Production default
Use a persistent checkpointer (Postgres or equivalent). In-memory checkpoints are for demos. Pair either path with traces and offline evals that block merges.
