{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "profile": {
      "type": "string",
      "const": "owp-docs-draft/0.1",
      "description": "Draft discriminator. This value is not OWP v0.4 conformance or an alpha wire profile."
    },
    "nonce": {
      "type": "string",
      "pattern": "^[a-f0-9]{64}$",
      "description": "Source requires random 256-bit nonce; hexadecimal encoding is draft."
    },
    "issued_at": {
      "type": "string",
      "format": "date-time",
      "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:Z))$",
      "description": "Draft: UTC date-time, second precision, ending in Z."
    }
  },
  "required": [
    "profile",
    "nonce",
    "issued_at"
  ],
  "additionalProperties": false,
  "description": "§4.5: challenge every 60 seconds, response within 10.",
  "title": "HeartbeatChallenge",
  "$comment": "owp-docs-draft/0.1: proposed documentation shape only. Source: https://app.notion.com/p/338ed9cb3201819d96e9fc7b8e88594a §4.5. No production conformance claim."
}