docs: "## Sync KOReader Progress - Single Book\n\nSynchronizes reading progress for a single book from KOReader device.\n\n**Method:** POST\n\n**Endpoint:** /api/sync/koreader/progress\n\n**Authentication:** Bearer token (koreader_device_token)\n\n**Request Body:**\n- `library_id` (string, optional): Library UUID for multi-library setups\n- `books` (array): Array with single book progress\n  - `uuid` (string): Unique book identifier (often SHA-256 hash)\n  - `title` (string): Book title\n  - `authors` (array): List of authors\n  - `progress` (number): Progress decimal (0.0 to 1.0)\n  - `percentage` (number): Progress percentage (0.45 = 45%)\n  - `last_read` (string): ISO 8601 timestamp of last read\n  - `chapter` (integer): Current chapter number\n  - `epubcfi` (string): EPUB Canonical Fragment Identifier\n  - `character` (integer): Character position in book\n  - `page` (integer, optional): Current page number\n\n**Response:**\n- `synced` (integer): Number of books synced\n- `timestamp`\
  \ (string): Server sync timestamp\n- `books` (array): Sync results\n  - `uuid` (string): Book UUID\n  - `status` (string): `synced`, `updated`, `skipped`\n  - `server_progress` (object): Server-side progress data\n\n**Status Codes:**\n- 200: Success\n- 401: Unauthorized\n- 400: Invalid request format\n\n**KOReader Progress Tracking:**\n- SHA-256 based book identification (universal across devices)\n- EPUB CFI for precise location (standard format)\n- Chapter-based navigation\n- Character-level precision\n- Supports EPUB, FB2, PDF, DJVU, MOBI formats\n\n**EPUB CFI Format:**\n- Standardized location format for EPUBs\n- Example: `epubcfi(/6/4/2:15)`\n- Identifies exact position even after reflow\n- Works across different devices/apps\n- Preserved after file modifications\n\n**Book Identification:**\n- Primary: SHA-256 hash of book file\n- Universal: Same book = same UUID across devices\n- Format-agnostic: Works for any supported format\n- Case-sensitive: Hash must match exactly\n\n**Use Cases:**\n\
  - Real-time page turn sync\n- Progress backup\n- Cross-device continuity\n- Reading time tracking\n- Chapter completion detection"
http:
  body:
    json:
      books:
      - authors:
        - Author Name
        chapter: 3
        character: 15432
        epubcfi: epubcfi(/6/4/2:15)
        last_read: '2026-01-30T20:00:00Z'
        percentage: 0.45
        progress: 0.45
        title: Book Title
        uuid: '{{media_item_id}}'
      library_id: optional-library-uuid
    type: json
  headers:
  - key: Content-Type
    value: application/json
  method: POST
  url: '{{base_url}}/api/sync/koreader/progress'
  auth:
    type: bearer
    token: '{{koreader_device_token}}'
info:
  name: Sync Progress - Single Book
  seq: 1
  type: http