Resilient Document Generation Workflow (Multi-Engine Fallback)

When to Use

Use this skill when document generation tasks fail or when

shell_agent

• Generating documents in multiple formats (

  .docx

  ,

  .pdf

  ,

  .html

  )
• PDF generation fails due to missing LaTeX, encoding issues, or tool errors
• Documents contain special characters, symbols, or non-ASCII text
• You need maximum reliability with automatic fallback options

Core Technique

Split document generation into discrete, observable steps with cascading fallbacks for PDF generation:

1. Content creation → Use

   write_file

   to create source Markdown
2. Unicode sanitization → Use Python script for reliable character replacement
3. Format conversion → Try multiple PDF engines in sequence until one succeeds
4. Verification → Check file exists, has non-zero size, and is valid

⚠️ Unicode & PDF Engine Guide

Different PDF engines have different Unicode support:

pdflatex

xelatex

wkhtmltopdf

reportlab

fpdf2

Character Replacement Table

—

--

–

-

" "

" "

' '

'

…

...

→

←

↑

↓

->

<-

^

v

✓

✗

[x]

[ ]

★

●

*

-

©

®

™

(c)

(r)

(tm)

é

ñ

ü

Step-by-Step Workflow

Step 1: Create Source Content with write_file

Write your document content as Markdown to a source file:

write_file
path: /tmp/document_source.md
content: |
  # Document Title
  
  ## Section 1
  Content here...
  
  ## Section 2
  More content...

Step 2: Sanitize Unicode with Python Script

Create a reusable Python sanitizer for reliable character replacement:

write_file
path: /tmp/sanitize_unicode.py
content: |
  #!/usr/bin/env python3
  import sys
  import re
  
  if len(sys.argv) < 2:
      print("Usage: sanitize_unicode.py <input.md> [output.md]")
      sys.exit(1)
  
  input_file = sys.argv[1]
  output_file = sys.argv[2] if len(sys.argv) > 2 else input_file.replace('.md', '_sanitized.md')
  
  replacements = {
      '—': '--',    # em dash
      '–': '-',     # en dash
      '"': '"',     # left curly quote
      '"': '"',     # right curly quote
      "'": "'",     # left curly apostrophe
      "'": "'",     # right curly apostrophe
      '…': '...',   # ellipsis
      '→': '->',    # right arrow
      '←': '<-',    # left arrow
      '↑': '^',     # up arrow
      '↓': 'v',     # down arrow
      '✓': '[x]',   # checkmark
      '✗': '[ ]',   # cross
      '★': '*',     # star
      '●': '-',     # bullet
      '©': '(c)',   # copyright
      '®': '(r)',   # registered
      '™': '(tm)',  # trademark
  }
  
  with open(input_file, 'r', encoding='utf-8') as f:
      content = f.read()
  
  for old, new in replacements.items():
      content = content.replace(old, new)
  
  with open(output_file, 'w', encoding='utf-8') as f:
      f.write(content)
  
  print(f"Sanitized: {input_file} -> {output_file}")

Apply sanitization for PDF:

run_shell
command: python3 /tmp/sanitize_unicode.py /tmp/document_source.md /tmp/document_source_sanitized.md

Note: Keep original for DOCX/HTML (these formats handle Unicode well).

Step 3: Convert to Target Formats with Cascading Fallbacks

For DOCX (from original, no sanitization needed):

run_shell
command: pandoc /tmp/document_source.md -o output.docx

For PDF (try multiple engines in sequence):

Attempt 1: pdflatex (fastest, limited Unicode)

run_shell
command: pandoc /tmp/document_source_sanitized.md -o output.pdf --pdf-engine=pdflatex

If pdflatex fails, Attempt 2: xelatex (full Unicode)

run_shell
command: pandoc /tmp/document_source.md -o output.pdf --pdf-engine=xelatex

If xelatex fails, Attempt 3: wkhtmltopdf (web-based)

run_shell
command: pandoc /tmp/document_source.md -o output.pdf --pdf-engine=wkhtmltopdf

If all pandoc engines fail, Attempt 4: Python reportlab

write_file
path: /tmp/generate_pdf_reportlab.py
content: |
  #!/usr/bin/env python3
  from reportlab.lib.pagesizes import letter
  from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer
  from reportlab.lib.styles import getSampleStyleSheet
  import markdown
  
  input_md = '/tmp/document_source.md'
  output_pdf = 'output.pdf'
  
  with open(input_md, 'r', encoding='utf-8') as f:
      md_content = f.read()
  
  html_content = markdown.markdown(md_content)
  
  doc = SimpleDocTemplate(output_pdf, pagesize=letter)
  styles = getSampleStyleSheet()
  story = []
  
  # Simple HTML to flowables (basic implementation)
  for line in html_content.split('\n'):
      if line.strip():
          story.append(Paragraph(line, styles['Normal']))
          story.append(Spacer(1, 6))
  
  doc.build(story)
  print(f"PDF created: {output_pdf}")

run_shell
command: python3 /tmp/generate_pdf_reportlab.py

If reportlab fails, Attempt 5: Python fpdf2 (simpler)

write_file
path: /tmp/generate_pdf_fpdf.py
content: |
  #!/usr/bin/env python3
  from fpdf import FPDF
  
  input_md = '/tmp/document_source.md'
  output_pdf = 'output.pdf'
  
  pdf = FPDF()
  pdf.add_page()
  pdf.set_font('Helvetica', '', 12)
  
  with open(input_md, 'r', encoding='utf-8') as f:
      for line in f:
          # Simple line-by-line, escape special chars
          safe_line = line.encode('latin-1', 'replace').decode('latin-1')
          pdf.cell(0, 10, safe_line[:180], ln=True)
  
  pdf.output(output_pdf)
  print(f"PDF created: {output_pdf}")

run_shell
command: python3 /tmp/generate_pdf_fpdf.py

For HTML (from original):

run_shell
command: pandoc /tmp/document_source.md -o output.html

Step 4: Verify Outputs with Multiple Checks

Check 1: Files exist and have size

run_shell
command: ls -lh output.docx output.pdf output.html 2>/dev/null && echo "FILES_OK" || echo "FILES_MISSING"

Check 2: Validate PDF is not corrupted

run_shell
command: python3 -c "import fitz; doc=fitz.open('output.pdf'); print(f'PDF_VALID: {doc.page_count} pages')" 2>/dev/null || echo "PDF_CHECK_SKIPPED"

Check 3: Validate DOCX

run_shell
command: python3 -c "from docx import Document; d=Document('output.docx'); print(f'DOCX_VALID: {len(d.paragraphs)} paragraphs')" 2>/dev/null || echo "DOCX_CHECK_SKIPPED"

Check 4: Read back content for manual verification

read_file
filetype: md
file_path: output.html

Complete Example

# Generate Negotiation Strategy Document (Resilient Workflow)

## Step 1: Write Markdown source
write_file
path: /tmp/negotiation_strategy.md
content: |
  # Negotiation Strategy
  
  ## Executive Summary
  Content with original unicode characters...
  
  ## Resolution Path
  More content...

## Step 2: Sanitize for PDF
write_file
path: /tmp/sanitize_unicode.py
content: |
  [Python sanitizer script from Step 2 above]

run_shell
command: python3 /tmp/sanitize_unicode.py /tmp/negotiation_strategy.md /tmp/negotiation_strategy_sanitized.md

## Step 3: Convert to DOCX (original, Unicode-safe format)
run_shell
command: pandoc /tmp/negotiation_strategy.md -o negotiation_strategy.docx

## Step 4: Convert to PDF (try pdflatex first)
run_shell
command: pandoc /tmp/negotiation_strategy_sanitized.md -o negotiation_strategy.pdf --pdf-engine=pdflatex

## Step 4b: If pdflatex failed, try xelatex
run_shell
command: pandoc /tmp/negotiation_strategy.md -o negotiation_strategy.pdf --pdf-engine=xelatex

## Step 4c: If xelatex failed, try wkhtmltopdf
run_shell
command: pandoc /tmp/negotiation_strategy.md -o negotiation_strategy.pdf --pdf-engine=wkhtmltopdf

## Step 5: Convert to HTML (original)
run_shell
command: pandoc /tmp/negotiation_strategy.md -o negotiation_strategy.html

## Step 6: Verify all outputs
run_shell
command: ls -lh negotiation_strategy.* && echo "ALL_FILES_CREATED"

run_shell
command: python3 -c "import fitz; d=fitz.open('negotiation_strategy.pdf'); print(f'PDF: {d.page_count} pages')"

Advantages Over shell_agent

Troubleshooting by Error Type

"LaTeX not found" or "pdflatex: command not found"

• Solution: Try

  --pdf-engine=xelatex

  or

  --pdf-engine=wkhtmltopdf

• Install LaTeX:

  apt-get install texlive-latex-recommended texlive-fonts-recommended

• Or fallback to Python: Use reportlab/fpdf2 approach

"Encoding error" or "UnicodeDecodeError"

• Solution: Use sanitized markdown file (Step 2)
• Or: Add

  -f markdown+utf8

  to pandoc command
• Or: Try xelatex engine (better Unicode support)

"wkhtmltopdf not found"

• Solution: Install via

  apt-get install wkhtmltopdf

  or fallback to Python

"ModuleNotFoundError: No module named 'reportlab'"

• Solution:

  pip install reportlab

  or fallback to fpdf2

"Invalid PDF" or corrupted output

• Diagnosis: Run

  pdftotext output.pdf -

  to check if text extracts
• Solution: Try different PDF engine from fallback chain

DOCX formatting issues

• Solution: Add

  --reference-doc=template.docx

  for custom styles
• Or: Fix markdown structure in source file

All pandoc commands fail

• Check:

  pandoc --version

  to verify installation
• Fallback: Use Python-based PDF generation (reportlab/fpdf2)
• For DOCX: Try

  python-docx

  library directly

Pre-Flight Checks (Optional but Recommended)

Before starting, verify required tools are available:

run_shell
command: pandoc --version && echo "PANDOC_OK" || echo "PANDOC_MISSING"
run_shell
command: pdflatex --version && echo "PDFLATEX_OK" || echo "PDFLATEX_MISSING"
run_shell
command: python3 -c "import reportlab" && echo "REPORTLAB_OK" || echo "REPORTLAB_MISSING"

This helps you know which fallback path will be needed.

Related Skills

• document-gen-unicode-safe

  : Parent skill with basic Unicode guidance

• document-gen-fallback

  : Original fallback without Unicode or multi-engine support
• Use this skill when you need maximum reliability with automatic fallbacks

When to Return to shell_agent

After manually completing this workflow successfully once for a document type, you can attempt

shell_agent