Enumerate all active channels of the application

{
  "type": "object",
  "properties": {
    "by": {
      "type": "string",
      "enum": [
        "value",
        "id"
      ]
    },
    "limit": {
      "type": "integer"
    },
    "prefix": {
      "type": "string"
    }
  },
  "additionalProperties": false
}