Imported from majiayu000/claude-skill-registry (skills/data/ai-html-generate/SKILL.md). Install upstream with npx skills add majiayu000/claude-skill-registry --skill ai-html-generate. Copyright stays with the author.

AI HTML Generate Skill

Purpose

This skill leverages AI's probabilistic generation capabilities to recreate PDF pages as semantic HTML. The AI receives three complementary inputs that together provide complete context:

1. Visual reference (PNG image) - Page layout and visual hierarchy
2. Text data (rich_extraction.json) - Accurate text content and formatting metadata
3. Structural preview (ASCII text) - Logical layout and element relationships

This three-input approach ensures the AI understands not just what text to include, but how it should be structured semantically in HTML.

The output is probabilistic (AI-generated), but will be made deterministic by validation gates in subsequent skills.

What to Do

1. Prepare three input files

   • Load 02_page_XX.png (image file)
   • Load 01_rich_extraction.json (text spans with metadata)
   • Load 03_page_XX_ascii.txt (structure preview)

2. Construct AI prompt

   • Attach PNG image as visual reference
   • Include extracted text data (JSON)
   • Include ASCII preview (text representation)
   • Provide specific generation requirements

3. Invoke Claude API with complete context

   • Send multi-modal prompt (text + image)
   • Request semantic HTML5 output
   • Specify CSS classes and structure requirements

4. Parse and save generated HTML

   • Extract HTML from AI response
   • Validate basic well-formedness
   • Save to persistent file with metadata

5. Log generation metadata

   • Record AI model used
   • Timestamp generation
   • List input files used
   • Store any confidence indicators from AI

Input Files (From Previous Skills)

Input 1: Rendered PDF Page (PNG)

File: output/chapter_XX/page_artifacts/page_YY/02_page_XX.png

• High-resolution rendering of PDF page
• 300+ DPI for visual clarity
• Shows actual page appearance
• Used for visual layout understanding

Input 2: Rich Extraction Data (JSON)

File: output/chapter_XX/page_artifacts/page_YY/01_rich_extraction.json

• Text spans with complete metadata
• Font names, sizes, bold/italic flags
• Position information (bounding boxes)
• Sequence and relationships

Input 3: ASCII Preview (Text)

File: output/chapter_XX/page_artifacts/page_YY/03_page_XX_ascii.txt

• Text-based structural representation
• Heading hierarchy marked
• Lists and bullets identified
• Paragraph flow documented
• Element types annotated

AI Prompt Template

The prompt sent to Claude:

You are recreating a PDF textbook page as semantic HTML5.

You have three pieces of information about this page:
1. A visual rendering (PNG image) - to understand layout
2. Parsed text data (JSON) - to ensure accuracy
3. An ASCII structure preview (text) - to understand element relationships

VISUAL REFERENCE:
[PNG Image Attached]

PARSED TEXT DATA:
[JSON Attached]

STRUCTURAL PREVIEW:
[ASCII Text Attached]

TASK:
Generate semantic HTML5 that accurately recreates this page.

REQUIREMENTS:

1. HTML5 Structure:
   - Proper DOCTYPE, html, head, body tags
   - Meta charset="UTF-8"
   - Meta viewport for responsive design
   - Title tag with descriptive text

2. Content Wrapper:
   - Single <div class="page-container"> wrapper
   - Single <main class="page-content"> for all content
   - No page breaks or paginated structure

3. Semantic HTML Elements:
   - Use proper heading tags (h1-h6) based on hierarchy
   - Use <p> for paragraphs
   - Use <ul> and <li> for bullet lists
   - Use <table> if data tables present
   - Use <figure> and <figcaption> for images/exhibits

4. Semantic CSS Classes:
   Apply these classes based on detected element types:

   Page Structure:
   - page-container (main wrapper)
   - page-content (content area)
   - chapter-header (chapter opening section)
   - chapter-number (numeric chapter marker)
   - chapter-title (chapter main title)

   Content Elements:
   - section-heading (major section, h2)
   - subsection-heading (minor section, h3-h4)
   - paragraph (body text, p)
   - bullet-list (ul)
   - bullet-item (li)

   Navigation & Structure:
   - section-navigation (list of topics/sections)
   - nav-item (individual nav item)
   - section-divider (hr divider line)

   Special Elements:
   - exhibit (table or figure)
   - exhibit-table (actual table)
   - exhibit-title (figure/table caption)
   - image-placeholder (for embedded images)

5. Content Preservation & Boundary Integrity:
   - Include ALL text content from the parsed data
   - Preserve exact text (no paraphrasing or edits)
   - Maintain original structure and relationships
   - Do not omit or skip sections

   CRITICAL - PAGE BOUNDARY RULES:
   - Start page content EXACTLY where JSON starts it
   - End page content EXACTLY where JSON ends it
   - NEVER add bridging text, connectors, or completing phrases
   - NEVER invent transitional words or sentences
   - NEVER synthesize content to "smooth" page transitions
   - Pages may start or end mid-sentence - this is EXPECTED and CORRECT
   - If a sentence seems incomplete, that is the accurate page boundary
   - Every single word in your HTML MUST exist in the source JSON

6. Heading Hierarchy:
   - Follow logical hierarchy (h1 → h2 → h3 → h4)
   - No skipped levels (don't jump from h1 to h4)
   - Chapter title is h1 (if present)
   - Main sections are h2
   - Subsections are h3 or h4 as appropriate

7. List Formatting:
   - Wrap in <ul class="bullet-list">
   - Each item in <li class="bullet-item">
   - Preserve item order and grouping
   - Include all bullet text exactly

8. CSS Stylesheet Link:
   - Include: <link rel="stylesheet" href="../../styles/main.css">
   - Use relative path (two levels up to root)
   - This stylesheet provides all styling

9. Special Handling:
   - Bold text within paragraphs: Use <strong> tags
   - Italic text: Use <em> tags
   - Embedded images: Use <img> tags with src path and alt text
   - Exhibits/tables: Preserve structure and captions

OUTPUT FORMAT:

Return ONLY valid HTML5. Do not include explanations.

```html
<!DOCTYPE html>
<html lang="en">
<head>
    ...
</head>
<body>
    ...
</body>
</html>

VALIDATION:

• HTML must be valid HTML5
• All opening tags must have closing tags
• Class attributes must use correct class names
• All text content from JSON MUST be included
• NO TEXT MAY BE ADDED that doesn't exist in the source JSON extraction
• Coverage must be 99-100% (>100% indicates invented content = FAIL)
• Every single word must come from the extraction data

## Process Flow

┌─ Load Input Files ─────────────────────┐ │ • 02_page_XX.png (image) │ │ • 01_rich_extraction.json (text data) │ │ • 03_page_XX_ascii.txt (structure) │ └────────┬────────────────────────────────┘ │ ▼ ┌─ Construct Prompt ─────────────────────┐ │ • Attach PNG image │ │ • Include JSON data │ │ • Include ASCII preview │ │ • Add generation requirements │ └────────┬────────────────────────────────┘ │ ▼ ┌─ Invoke Claude API ────────────────────┐ │ • Multi-modal prompt │ │ • Vision + Text understanding │ │ • Deterministic system instructions │ └────────┬────────────────────────────────┘ │ ▼ ┌─ Extract & Save HTML ──────────────────┐ │ • Parse AI response │ │ • Extract HTML block │ │ • Basic validation (tag closure) │ │ • Save to 04_page_XX.html │ └────────┬────────────────────────────────┘ │ ▼ ┌─ Log Generation Metadata ──────────────┐ │ • Model name and version │ │ • Input file references │ │ • Timestamp │ │ • Save to 05_generation_metadata.json │ └────────┬────────────────────────────────┘ │ ▼ ┌─ GATE 1: Verify Text Content ──────────┐ │ MANDATORY - DO NOT SKIP │ │ │ │ Run per-page text verification: │ │ python3 Calypso/tools/ │ │ verify_text_content.py 1 │ │ │ │ Check coverage percentage: │ │ • 99-100% = PASS, proceed to next page │ │ • 95-98% = WARNING, review content │ │ • >100% = FAIL, REGENERATE (hallucin) │ │ • <85% = FAIL, REGENERATE PAGE │ │ │ │ CRITICAL: Never consolidate pages │ │ until all individual pages pass ✓ │ └────────┬─────────────────────────────┘ │ ▼ ✓ Complete - Ready for Validation

## GATE 1: MANDATORY Per-Page Text Verification

**This is the fail-safe that prevents incorrect content from reaching consolidation.**

After generating each page's HTML with the AI prompt above:

1. **Immediately run verification:**
   ```bash
   python3 Calypso/tools/verify_text_content.py <chapter_num> <page_num>

2. Interpret results:

   • 99-100% coverage: PASS ✅ - Text matches extraction JSON precisely, proceed to next page
   • 95-98% coverage: WARNING ⚠️ - Minor text differences, review content manually to ensure no loss
   • 85-95% coverage: WARNING ⚠️ - Some text missing/modified, review content manually
   • >100% coverage: FAIL ❌ - Extra content added not in original page (AI hallucination), REGENERATE IMMEDIATELY
   • <85% coverage: FAIL ❌ - Critical content missing, REGENERATE

3. If verification FAILS (<85% coverage):

   • Stop immediately
   • DO NOT proceed to next page
   • DO NOT consolidate chapter
   • Review the HTML - check if it contains:
     • Content from a DIFFERENT page (wrong page generated)
     • Missing sections or major text blocks
     • Corrupted or duplicate content
   • Regenerate the page with the AI prompt again
   • Re-run verification
   • Only proceed when coverage ≥95%

4. Example of FAIL scenarios:

   Extra content (>100% - AI HALLUCINATION):

   Page 16 HTML contains 301 words
   Page 16 JSON should have 297 words
   Coverage: 101.2% = FAIL ❌ (>100%)
   → Extra 4 words = AI invented bridging text
   → Example: AI added "All land also includes" that doesn't exist in source
   → Regenerate page 16 immediately with strict boundary constraints
   

   Missing content (<85%):

   Page X HTML contains 180 words
   Page X JSON should have 250 words
   Coverage: 72% = FAIL ❌ (<85%)
   → Missing 70 words from page X
   → Regenerate page X immediately
   

5. CONSOLIDATION BLOCK:

   • Do not run Skill 4 (consolidate) until all pages pass Gate 1
   • Consolidating pages with wrong content cascades the error to the entire chapter
   • Each page must verify individually first

Output Files

Generated HTML File

Path: output/chapter_XX/page_artifacts/page_YY/04_page_XX.html

Content: Complete HTML5 document with:

• DOCTYPE and proper tags
• Meta tags (charset, viewport)
• Title tag
• CSS stylesheet link
• Semantic structure with classes
• All extracted text content
• Proper heading hierarchy
• Lists and paragraphs formatted

Example structure:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Chapter 2: Rights in Real Estate - Pages 16-29</title>
    <link rel="stylesheet" href="../../styles/main.css">
</head>
<body>
    <div class="page-container">
        <main class="page-content">
            <!-- Opening chapter only -->
            <div class="chapter-header">
                <span class="chapter-number">2</span>
                <h1 class="chapter-title">Rights in Real Estate</h1>
            </div>

            <!-- Navigation (opening pages only) -->
            <nav class="section-navigation">
                <div class="nav-item">Real Property Rights</div>
                <div class="nav-item">...</div>
            </nav>

            <hr class="section-divider">

            <!-- Main content -->
            <h2 class="section-heading">REAL PROPERTY RIGHTS</h2>

            <p class="paragraph">Real property consists of...</p>

            <h4 class="subsection-heading">Physical characteristics.</h4>

            <p class="paragraph">Land has unique physical characteristics...</p>

            <ul class="bullet-list">
                <li class="bullet-item">Immobility - Land cannot be moved...</li>
                <li class="bullet-item">Indestructibility - Land is permanent...</li>
                <li class="bullet-item">Uniqueness - Each parcel is unique...</li>
            </ul>

            <!-- More content... -->
        </main>
    </div>
</body>
</html>

Generation Metadata

Path: output/chapter_XX/page_artifacts/page_YY/05_generation_metadata.json

{
  "page": 16,
  "book_page": 17,
  "chapter": 2,
  "generated_at": "2025-11-08T14:33:00Z",
  "ai_model": "claude-3-5-sonnet-20241022",
  "inputs_used": [
    "02_page_16.png",
    "01_rich_extraction.json",
    "03_page_16_ascii.txt"
  ],
  "html_file": "04_page_16.html",
  "content_metrics": {
    "headings_count": 4,
    "paragraphs_count": 3,
    "lists_count": 1,
    "list_items_count": 3,
    "images_count": 0
  },
  "generation_notes": "Successfully generated with all three input sources",
  "estimated_accuracy": "90%"
}

Implementation Notes

Handling Different Page Types

Chapter Opening Pages (first page of chapter):

• Include chapter number (h1 or span.chapter-number)
• Include chapter title (h1.chapter-title)
• Include navigation list (nav.section-navigation)
• Include section divider (hr.section-divider)

Continuation Pages (middle of chapter):

• No chapter header
• Start with main content (h2.section-heading or similar)
• Maintain heading hierarchy across page boundaries

Final Pages (end of chapter):

• Continue content seamlessly
• Include any summary sections (if present)
• End naturally without special footer

Pages with Images/Exhibits:

• Include tags for exhibits
• Include tags for titles
• Use for tabular data
• Embed image file references correctly

AI Generation Best Practices

1. Be specific about requirements - AI responds better to detailed instructions
2. Provide all three inputs - Together they remove ambiguity
3. Include examples - Show AI what good output looks like
4. Use structured prompts - Numbered lists are clearer than prose
5. Request validation - Ask AI to validate its own output

Quality Checks (Before Validation Gate)

Before passing to validation:

1. File created

   • HTML file exists and is readable
   • File size > 5KB (substantial content)

2. Basic structure

   • Contains <!DOCTYPE html>
   • Has <html> tags
   • Has <head> and <body>
   • Has <main class="page-content">

3. Metadata

   • Generation timestamp recorded
   • Input files listed
   • Model name recorded
   • All content metrics captured

Success Criteria

✓ HTML file generated successfully ✓ All three inputs consumed (PNG, JSON, ASCII) ✓ HTML structure is valid (basic checks pass) ✓ All text content included (no omissions) ✓ Semantic classes applied correctly ✓ Heading hierarchy is logical ✓ Ready for deterministic validation gate

Error Handling

If AI refuses to generate:

• Log error message from AI
• Check input files for corruption
• Retry with simplified prompt if needed

If HTML is malformed:

• Try to extract what's usable
• Log specific issues
• May fail validation gate (expected)

If image fails to attach:

• Fall back to text-only generation
• Note in metadata
• Proceed (visual context lost but text may be sufficient)

If JSON data is incomplete:

• Use text from ASCII preview as fallback
• Note in metadata
• Proceed with caution

Next Steps

Once HTML is generated:

1. Quality Gate 1 (html-structure-validate) checks basic structure
2. Skill 4 (consolidate pages) for full chapter
3. Quality Gate 2 (semantic-validate) checks classes and hierarchy
4. Final validation ensures quality standards met

Key Principle

AI generates probabilistically. Python validates deterministically. Together they produce reliable, high-quality output.

This skill provides the probabilistic generation, leveraging AI's understanding of context and structure. The validation gates that follow ensure the output meets quality standards.

Testing the Skill

To test HTML generation on Chapter 1:

# Generate HTML for page 6 (Chapter 1 opening)
# Inputs: 02_page_6.png, 01_rich_extraction.json, 03_page_6_ascii.txt
# Output: 04_page_6.html

Expected result: Valid semantic HTML that accurately represents page 6 content.