Mermaid Tools

Mermaid Tools

Overview

This skill enables extraction of Mermaid diagrams from markdown files and generation of high-quality PNG images. The skill bundles all necessary scripts (extract-and-generate.sh, extract_diagrams.py, and puppeteer-config.json) in the scripts/ directory for portability and reliability.

Core Workflow

Standard Diagram Extraction and Generation

Extract Mermaid diagrams from a markdown file and generate PNG images using the bundled extract-and-generate.sh script:

cd "${CLAUDE_SKILL_DIR}/scripts"
./extract-and-generate.sh "" ""

Parameters:

• ``: Path to the markdown file containing Mermaid diagrams
• `: (Optional) Directory for output files. Defaults to /diagrams`

Example:

cd "${CLAUDE_SKILL_DIR}/scripts"
./extract-and-generate.sh "" ""

What the Script Does

1. Extracts all Mermaid code blocks from the markdown file
2. Numbers them sequentially (01, 02, 03, etc.) in order of appearance
3. Generates .mmd files for each diagram
4. Creates high-resolution PNG images with smart sizing
5. Validates all generated PNG files

Output Files

For each diagram, the script generates:

• 01-diagram-name.mmd - Extracted Mermaid code
• 01-diagram-name.png - High-resolution PNG image

The numbering ensures diagrams maintain their order from the source document.

Advanced Usage

Custom Dimensions and Scaling

Override default dimensions using environment variables:

cd "${CLAUDE_SKILL_DIR}/scripts"
MERMAID_WIDTH=1600 MERMAID_HEIGHT=1200 ./extract-and-generate.sh "" ""

Available variables:

• MERMAID_WIDTH (default: 1200) - Base width in pixels
• MERMAID_HEIGHT (default: 800) - Base height in pixels
• MERMAID_SCALE (default: 2) - Scale factor for high-resolution output

High-Resolution Output for Presentations

cd "${CLAUDE_SKILL_DIR}/scripts"
MERMAID_WIDTH=2400 MERMAID_HEIGHT=1800 MERMAID_SCALE=4 ./extract-and-generate.sh "" ""

Print-Quality Output

cd "${CLAUDE_SKILL_DIR}/scripts"
MERMAID_SCALE=5 ./extract-and-generate.sh "" ""

Smart Sizing Feature

The script automatically adjusts dimensions based on diagram type (detected from filename):

• Timeline/Gantt: 2400×400 (wide and short)
• Architecture/System/Caching: 2400×1600 (large and detailed)
• Monitoring/Workflow/Sequence/API: 2400×800 (wide for process flows)
• Default: 1200×800 (standard size)

Context-aware naming in the extraction process helps trigger appropriate smart sizing.

Important Principles

Use Bundled Scripts

CRITICAL: Use the bundled extract-and-generate.sh script from this skill's scripts/ directory. All necessary dependencies are bundled together.

Change to Script Directory

Run the script from its own directory to properly locate dependencies (extract_diagrams.py and puppeteer-config.json):

cd "${CLAUDE_SKILL_DIR}/scripts"
./extract-and-generate.sh "" ""

Running the script without changing to the scripts directory first may fail due to missing dependencies.

Prerequisites Verification

Before running the script, verify dependencies are installed:

1. mermaid-cli: mmdc --version
2. Google Chrome: google-chrome-stable --version
3. Python 3: python3 --version

If any are missing, consult references/setup_and_troubleshooting.md for installation instructions.

Troubleshooting

For detailed troubleshooting guidance, refer to references/setup_and_troubleshooting.md, which covers:

• Browser launch failures
• Permission issues
• No diagrams found
• Python extraction failures
• Output quality issues
• Diagram-specific sizing problems

Quick fixes for common issues:

Permission denied:

chmod +x "${CLAUDE_SKILL_DIR}/scripts/extract-and-generate.sh"

Low quality output:

MERMAID_SCALE=3 ./extract-and-generate.sh "" ""

Chrome/Puppeteer errors: Verify all WSL2 dependencies are installed (see references for full list).

Bundled Resources

scripts/

This skill bundles all necessary scripts for Mermaid diagram generation:

• extract-and-generate.sh - Main script that orchestrates extraction and PNG generation
• extract_diagrams.py - Python script for extracting Mermaid code blocks from markdown
• puppeteer-config.json - Chrome/Puppeteer configuration for WSL2 environment

All scripts must be run from the scripts/ directory to properly locate dependencies.

references/setupandtroubleshooting.md

Comprehensive reference documentation including:

• Complete prerequisite installation instructions
• Detailed environment variable reference
• Extensive troubleshooting guide
• WSL2-specific Chrome dependency setup
• Validation procedures

Load this reference when dealing with setup issues, installation problems, or advanced customization needs.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: daymade
• Source: daymade/claude-code-skills
• License: MIT

Install and usage instructions live in the source repository linked above.