{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "attempt": {
      "maximum": 9007199254740991,
      "minimum": 0,
      "type": "integer"
    },
    "channel": {
      "enum": [
        "inbox",
        "email_push_external",
        "in_product",
        "machine_callback"
      ],
      "type": "string"
    },
    "notification_id": {
      "pattern": "^ntf_[0-7][0123456789abcdefghjkmnpqrstvwxyz]{25}$",
      "type": "string"
    },
    "outcome": {
      "enum": [
        "delivered",
        "acknowledged",
        "retryable_failure",
        "permanent_failure",
        "superseded"
      ],
      "type": "string"
    },
    "reason_code": {
      "maxLength": 64,
      "type": "string"
    }
  },
  "required": [
    "notification_id",
    "channel",
    "outcome",
    "attempt"
  ],
  "type": "object"
}