Idempotency key
A unique value sent with a request so that a retry is recognised and not carried out twice.
An idempotency key is a unique value a client sends with a request so that, if the request is retried, the server recognises it and does not perform the action twice. The Agentic Commerce Protocol's delegate payment interface accepts one and rejects a reused key with different parameters as a conflict. Agents retry and resume often, and some frameworks re-run steps after an approval pause, so every money-moving call should carry one.
Agent Minute explains this term on 27 February 2027.
Related terms
Delegated paymentGiving an agent a payment token limited by an allowance, such as amount, currency, merchant and expiry.Audit trailA chronological record of who accessed a system and what operations they performed, enough to reconstruct events.Checkout sessionIn ACP, the stateful object an agent and seller update together, from items and options to completion.Excessive agencyGiving an LLM application more functions, permissions or autonomy than needed, so bad outputs cause harmful actions.