{
  "ok": true,
  "challenge": {
    "id": "e6635799a05a2e94aaa7ee56",
    "nonce": "634334ed31bdc4490232c99f58c1d41a4a02413a",
    "issuedAt": "2026-04-06T13:52:49.388Z",
    "expiresAt": "2026-04-06T14:02:49.388Z",
    "signature": "2b6aa5321525a4ee00f0a936a2e0c9130ec0eaf7dccbed1ff7284a22638d2bf5",
    "algorithm": "HMAC-SHA256",
    "version": "v1",
    "payloadSignatureSpec": "sha256_hex(challenge.id + ':' + challenge.nonce + ':' + canonical_json(payload))"
  }
}