{
  "$id": "https://sessionpipe.org/schema/v1/control-ack.json",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "acks": {
      "minItems": 1,
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string",
            "pattern": "^[0-9A-HJKMNP-TV-Z]{26}$"
          },
          "outcome": {
            "type": "string",
            "enum": [
              "delivered",
              "expired",
              "unsupported",
              "failed"
            ]
          },
          "at": {
            "type": "string",
            "format": "date-time",
            "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d\\.\\d{3}(?:Z))$"
          },
          "detail": {
            "type": "string",
            "maxLength": 500
          }
        },
        "required": [
          "id",
          "outcome",
          "at"
        ]
      }
    }
  },
  "required": [
    "acks"
  ]
}