Review and edit an action before it runs

Reviewing and editing is a human-in-the-loop pattern: the graph pauses with a proposed action, and the human resumes with a corrected value that the graph then uses.

Last updated: 27 Sep, 2026 · LangGraph 1.2

The interrupt lesson paused for a yes or no. Often a person wants to change the action, not only approve it, so the value they send back on resume becomes the one the graph uses.

Pausing with a proposed action

The node calls interrupt with the draft it proposes. Whatever the human returns on resume comes back as the value of that call.

def review(state):
    approved = interrupt({"proposed": state["draft"]})  # pause, show the draft
    return {"sent": approved}   # use the returned value, edited or not

Resuming with an edited value

Run once to hit the pause, then resume with Command(resume=...) carrying the corrected value. A checkpointer is required so the run can wait.

graph.invoke({"draft": "Refund $100", "sent": ""}, cfg)   # stops at the pause
out = graph.invoke(Command(resume="Refund $50"), cfg)     # human edits it
print(out["sent"])

Editing a refund before it is sent

The whole program in one file.

from typing_extensions import TypedDict
from langgraph.graph import StateGraph, START, END
from langgraph.types import interrupt, Command
from langgraph.checkpoint.memory import InMemorySaver

class State(TypedDict):
    draft: str
    sent: str

def review(state):
    approved = interrupt({"proposed": state["draft"]})  # pause and show the draft
    return {"sent": approved}                            # use what the human returns

b = StateGraph(State)
b.add_node("review", review)
b.add_edge(START, "review")
b.add_edge("review", END)
graph = b.compile(checkpointer=InMemorySaver())

cfg = {"configurable": {"thread_id": "1"}}
graph.invoke({"draft": "Refund $100", "sent": ""}, cfg)  # runs up to the pause
out = graph.invoke(Command(resume="Refund $50"), cfg)    # human edits, then resume
print(out["sent"])

What the human changed

• The run paused at interrupt with the proposed draft, "Refund $100".
• The human resumed with "Refund $50", so interrupt returned that value.
• The node wrote the edited value to sent, so the graph acted on the correction.

Approve only vs review and edit

When to let a human edit

• A money amount, a recipient or a destructive action a person should adjust.
• A tool call whose arguments a reviewer wants to correct before it runs.
• A draft reply a human tidies before it is sent.

Related

• Previous: interrupt: pause for a human
• Next: Streaming: watch a run happen