compile()

compile() turns a StateGraph definition into a runnable graph. Compilation performs structural checks and accepts runtime features such as a checkpointer or static breakpoints.¹

Tiny example

from langgraph.checkpoint.memory import InMemorySaver

graph = builder.compile(checkpointer=InMemorySaver())
result = graph.invoke(
    {"order_id": "A-104", "status": "new"},
    {"configurable": {"thread_id": "order-A-104"}},
)

1. Build nodes and edges.
2. Compile once.
3. Invoke the compiled graph many times with different inputs.

Failure note

Compilation checks graph structure; it does not call every API or prove every route works. Test success, failure, loop termination, and resume paths separately.

Related

• StateGraph
• Checkpoints and threads
• invoke() and ainvoke()

Footnotes

1. LangChain, Graph API overview. ↩