{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://drafts.opds.io/schema/progression.schema.json",
  "title": "OPDS Progression Document",
  "type": "object",
  "properties": {
    "title": {
      "type": "string"
    },
    "modified": {
      "type": "string",
      "format": "date-time"
    },
    "device": {
      "type": "object",
      "properties": {
        "id": {
          "type": "string",
          "format": "uri"
        },
        "name": {
          "type": "string",
          "minLength": 1
        }
      },
      "required": [
        "id",
        "name"
      ]
    },
    "progression": {
      "type": "number",
      "minimum": 0,
      "maximum": 1
    },
    "references": {
      "type": "array",
      "items": {
        "type": "string",
        "format": "uri-reference"
      }
    }
  },
  "required": [
    "modified",
    "device",
    "progression"
  ]
}