{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://synacl.com/protocol/v1/schemas/alert.json",
  "title": "Device alert",
  "description": "An alert raised at the edge for one device (for example a threshold the gateway evaluated locally). Published on `<prefix>/devices/{deviceId}/alert` or `tenants/{tenantId}/devices/{deviceId}/alert`. Stored as an event and shown to the user; it does not change device presence.",
  "type": "object",
  "required": [
    "ts",
    "severity",
    "code"
  ],
  "properties": {
    "ts": {
      "description": "When the condition was detected (epoch milliseconds).",
      "type": "integer",
      "minimum": 0
    },
    "severity": {
      "type": "string",
      "enum": [
        "info",
        "warning",
        "critical"
      ]
    },
    "code": {
      "description": "Short machine-readable reason, e.g. `THRESHOLD_VIOLATION`.",
      "type": "string",
      "maxLength": 64
    },
    "message": {
      "description": "Human-readable text.",
      "type": "string",
      "maxLength": 512
    },
    "tag": {
      "description": "Optional — the tag the alert is about, when it is tag-specific.",
      "type": "string"
    },
    "value": {
      "description": "Optional — the value that triggered it. Any JSON type."
    }
  },
  "additionalProperties": false
}