mermaid-tools

Extracts Mermaid diagrams from markdown files and generates high-quality PNG images using bundled scripts. Activates when working with Mermaid diagrams, converting diagrams to PNG, extracting diagrams from markdown, or processing markdown files with embedded Mermaid code.

25 stars

Best use case

mermaid-tools is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Extracts Mermaid diagrams from markdown files and generates high-quality PNG images using bundled scripts. Activates when working with Mermaid diagrams, converting diagrams to PNG, extracting diagrams from markdown, or processing markdown files with embedded Mermaid code.

Teams using mermaid-tools should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

  • You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

  • You only need a quick one-off answer and do not need a reusable workflow.
  • You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/mermaid-tools/SKILL.md --create-dirs "https://raw.githubusercontent.com/ComeOnOliver/skillshub/main/skills/daymade/claude-code-skills/mermaid-tools/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/mermaid-tools/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How mermaid-tools Compares

Feature / Agentmermaid-toolsStandard Approach
Platform SupportNot specifiedLimited / Varies
Context Awareness High Baseline
Installation ComplexityUnknownN/A

Frequently Asked Questions

What does this skill do?

Extracts Mermaid diagrams from markdown files and generates high-quality PNG images using bundled scripts. Activates when working with Mermaid diagrams, converting diagrams to PNG, extracting diagrams from markdown, or processing markdown files with embedded Mermaid code.

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

SKILL.md Source

# 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:

```bash
cd ~/.claude/skills/mermaid-tools/scripts
./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

**Parameters:**
- `<markdown_file>`: Path to the markdown file containing Mermaid diagrams
- `<output_directory>`: (Optional) Directory for output files. Defaults to `<markdown_file_directory>/diagrams`

**Example:**
```bash
cd ~/.claude/skills/mermaid-tools/scripts
./extract-and-generate.sh "/path/to/document.md" "/path/to/output"
```

### 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:

```bash
cd ~/.claude/skills/mermaid-tools/scripts
MERMAID_WIDTH=1600 MERMAID_HEIGHT=1200 ./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

**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

```bash
cd ~/.claude/skills/mermaid-tools/scripts
MERMAID_WIDTH=2400 MERMAID_HEIGHT=1800 MERMAID_SCALE=4 ./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

### Print-Quality Output

```bash
cd ~/.claude/skills/mermaid-tools/scripts
MERMAID_SCALE=5 ./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

## 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`):

```bash
cd ~/.claude/skills/mermaid-tools/scripts
./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

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:**
```bash
chmod +x ~/.claude/skills/mermaid-tools/scripts/extract-and-generate.sh
```

**Low quality output:**
```bash
MERMAID_SCALE=3 ./extract-and-generate.sh "<markdown_file>" "<output_directory>"
```

**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/setup_and_troubleshooting.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.

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