{
  "slug": "idempotency-key",
  "term": "Idempotency key",
  "aliases": [
    "Idempotency token"
  ],
  "definition": "An idempotency key identifies attempts of one logical request so a service can recognize retries within its documented scope and retention rules.",
  "note": "Keep identity and parameters stable for a retry. DynamoDB TransactWriteItems documents a ClientRequestToken window of ten minutes after the first request completes; changed parameters within it are rejected, and later reuse is a new request. This service-specific rule is not a universal token lifetime. An identifier alone does not provide crash durability or duplicate suppression.",
  "related": [
    "idempotency",
    "retry-deduplication",
    "io-timeout"
  ],
  "citations": [
    {
      "id": "dynamodb-token",
      "title": "Amazon DynamoDB API Reference: TransactWriteItems, ClientRequestToken contract.",
      "url": "https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_TransactWriteItems.html#DDB-TransactWriteItems-request-ClientRequestToken",
      "accessed": "2026-10-15"
    },
    {
      "id": "hesela-timeouts",
      "title": "Storage timeouts: an expired timer is not a cancelled write",
      "url": "https://hesela.com/analyses/storage-timeouts-uncertain-completion/",
      "accessed": "2026-10-15"
    }
  ],
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-15"
}