Convert Ebooks to PDF API - Professional Book PDF Generation

#What Ebooks to PDF solves

Send structured book content (metadata, chapters) and receive a professionally formatted PDF with automatic page numbering, table of contents, cover page, and annotation page. Ideal for self-publishing, manuscript generation, print-on-demand, and document archival. Supports 150+ customization options including fonts, spacing, margins that auto-adjust based on font size.

#Endpoint & when to use it

#POST https://api.yeb.to/v1/ebooks/pdf/convert-from-file

• Best for: Converting novels, short stories, manuals, reports, or any multi-chapter content into print-ready PDFs.
• How it works: We render your content using the elegant-novel template with Blade + Puppeteer/Chromium for pixel-perfect output.
• Output format: High-quality A4/A5/Letter PDFs with professional typography and automatic layout.
• Processing time: ~2-5 seconds depending on content length and customization complexity.

#Quick start

Step 1: Create a JSON file with your book data and upload it to a public URL

# book.json (minimal example)
{
  "template": "elegant-novel",
  "metadata": {
    "title": "The Great Gatsby",
    "author": "F. Scott Fitzgerald"
  },
  "chapters": [
    {
      "title": "Chapter I",
      "content": "In my younger and more vulnerable years..."
    }
  ]
}

Step 2: Call the API with the file URL

curl -X POST "https://api.yeb.to/v1/ebooks/pdf/convert-from-file" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"file_url": "https://yourdomain.com/books/book.json"}'

#Parameters that actually matter

#JSON file structure

Your JSON file at file_url must contain:

#Key metadata fields

#Chapter formatting

Each chapter object requires:

• title — The chapter heading (e.g., "Chapter I", "Prologue").
• content — The chapter text. Use \n\n to separate paragraphs.

Optional chapter fields:

• subtitle — Chapter subtitle (shown below chapter title).
• number — Chapter number (for display if using chapter_number_format).

#Customization options that matter

#Typography & spacing

#Page format & orientation

#Custom metadata fields

Display additional information on the annotation page:

"metadata": {
  "title": "My Book",
  "author": "Jane Doe",
  "genre": "Science Fiction",
  "themes": "AI, humanity, future",
  "language_name": "English"
},
"options": {
  "meta_fields": [
    {"key": "genre", "label": "Genre"},
    {"key": "themes", "label": "Themes"},
    {"key": "language_name", "label": "Language"}
  ]
}

Any field in metadata can be displayed by adding it to meta_fields.

#Toggle sections on/off

#Reading & acting on responses

{
  "success": true,
  "pdf_url": "https://yeb.to/storage/ebooks/ebook_abc123.pdf",
  "pdf_size": 860031,
  "template": "elegant-novel",
  "generated_at": "2026-01-07T14:30:00+02:00",
  "response_code": 200,
  "response_time_ms": 4773
}

• pdf_url — Direct download URL. Files are kept for 24 hours, then auto-deleted.
• pdf_size — File size in bytes. Useful for bandwidth estimation.
• template — Template used for generation (currently only elegant-novel).
• generated_at — ISO 8601 timestamp. Use for cache invalidation or logging.
• response_time_ms — Processing time. Typically 2-5 seconds for standard books.

#Typical errors & how to fix

{ "error": "Metadata field 'title' is required", "response_code": 400 }

{ "error": "At least one chapter is required", "response_code": 400 }

{ "error": "Template 'unknown' not found", "response_code": 404 }

• 400 validation error: Check that metadata.title, metadata.author, and at least one chapter are provided.
• 401 invalid key: Verify your API key is correct and has sufficient credits.
• 404 template not found: Use elegant-novel as the template name.
• 500 generation failed: Check for malformed JSON or extremely large content. Contact support if persists.

#Troubleshooting & field notes

1. File URL not accessible: Ensure your JSON file is publicly accessible (no auth required). Test by opening the URL in a browser - it should download/display the JSON. Check CORS headers if serving from a different domain.
2. Invalid JSON format: Validate your JSON file before uploading. Use a JSON validator or jq to check syntax. Common errors: trailing commas, unquoted keys, smart quotes instead of straight quotes.
3. Text overlaps page numbers: The API auto-adjusts margins based on chapter_content_font_size. If using very large fonts (>20pt), verify the output. Margins scale automatically: 12pt = 22mm bottom, 16pt = 27mm bottom, 20pt = 32mm bottom.
4. Fonts not loading: Ensure options.include_fonts is true (default). For custom fonts, use options.custom_fonts with Google Fonts URLs.
5. Paragraphs not separating: Use \n\n (double newline) in chapter content to separate paragraphs, not single \n.
6. Custom metadata not showing: Add the field to both metadata object AND options.meta_fields array with matching key.
7. Processing timeout: Very long books (>500 pages) may timeout. Processing time: 10-50 pages = 5-15s, 50-200 pages = 30-60s, 200-500 pages = 2-3 minutes. Consider splitting into volumes if needed.
8. PDF file expires: PDFs are auto-deleted after 24 hours. Download immediately after generation or store on your own CDN.
9. Inconsistent spacing: Use the same chapter_content_line_height value for all requests to maintain consistency across documents.

#Best practices

• Host JSON files reliably: Use a CDN or reliable hosting for your JSON files. Ensure files remain accessible for the duration of the API call (2-3 minutes for large books).
• Validate JSON before upload: Use a JSON validator to catch syntax errors. Invalid JSON will fail immediately with a 400 error.
• Use descriptive filenames: Name files clearly (e.g., book-{id}-{timestamp}.json) for easier debugging and tracking.
• Cache responses: Same file_url = same output. Cache PDF URLs for 24h to avoid regenerating identical documents.
• Pre-validate content: Check for required fields (title, author, chapters) before creating JSON files.
• Use consistent font sizes: Pick one base font size (12pt, 14pt, or 16pt) for your brand and stick with it across all books.
• Store original JSON: Keep the JSON file for regeneration if needed. PDFs expire after 24h but JSON can be reused indefinitely.
• Test with real content: Short test chapters may not reveal pagination issues. Use realistic chapter lengths (2000+ words).
• Monitor response times: Small books: 5-15s, Medium: 30-60s, Large: 2-3 minutes. If consistently slower, check file_url accessibility.
• Handle 5xx errors gracefully: Implement retry logic with exponential backoff (wait 5s, then 10s, then 20s) for server errors.

#Real-world examples

Example 1: Self-publishing platform

Create mystery-novel.json:

{
  "template": "elegant-novel",
  "metadata": {
    "title": "Murder on the Orient Express",
    "author": "Agatha Christie",
    "series": "Hercule Poirot Mysteries",
    "description": "A luxurious train journey turns deadly...",
    "year": 1934,
    "publisher": "Collins Crime Club",
    "genre": "Mystery",
    "themes": "Murder, investigation, justice"
  },
  "chapters": [
    {"title": "Part I: The Facts", "content": "It was five o'clock on a winter's morning..."},
    {"title": "Part II: The Evidence", "content": "In a small room..."}
  ],
  "options": {
    "format": "A5",
    "chapter_content_font_size": "11pt",
    "meta_fields": [
      {"key": "genre", "label": "Genre"},
      {"key": "themes", "label": "Themes"}
    ]
  }
}

Call API:

curl -X POST "https://api.yeb.to/v1/ebooks/pdf/convert-from-file" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"file_url": "https://yourdomain.com/books/mystery-novel.json"}'

Example 2: Technical manual with custom branding

Create tech-manual.json:

{
  "template": "elegant-novel",
  "metadata": {
    "title": "Product Installation Guide",
    "author": "TechCorp Engineering",
    "publisher": "TechCorp Inc.",
    "year": 2026
  },
  "chapters": [
    {"title": "1. System Requirements", "content": "Before installation..."},
    {"title": "2. Installation Steps", "content": "Follow these steps..."},
    {"title": "3. Troubleshooting", "content": "If you encounter issues..."}
  ],
  "options": {
    "chapter_content_font_size": "12pt",
    "include_annotation": false,
    "chapter_show_number": true
  },
  "texts": {
    "copyright_text": "© {year} TechCorp Inc. All rights reserved.",
    "chapter_number_format": "Section {n}"
  }
}

Call API:

curl -X POST "https://api.yeb.to/v1/ebooks/pdf/convert-from-file" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"file_url": "https://yourdomain.com/manuals/tech-manual.json"}'

#API Changelog