Beautiful Mermaid Diagram Rendering

Render Mermaid diagrams as SVG and PNG images using the Beautiful Mermaid library.

Dependencies

This skill requires the agent-browser skill for PNG rendering. Load it before proceeding with PNG capture.

Supported Diagram Types

• Flowchart - Process flows, decision trees, CI/CD pipelines
• Sequence - API calls, OAuth flows, database transactions
• State - State machines, connection lifecycles
• Class - UML class diagrams, design patterns
• Entity-Relationship - Database schemas, data models

Available Themes

Default, Dracula, Solarized, Zinc Dark, Tokyo Night, Tokyo Night Storm, Tokyo Night Light, Catppuccin Latte, Nord, Nord Light, GitHub Dark, GitHub Light, One Dark.

If no theme is specified, use default.

Common Syntax Patterns

Flowchart Edge Labels

Use pipe syntax for edge labels:

A -->|label| B
A ---|label| B

Avoid space-dash syntax which can cause incomplete renders:

A -- label --> B   # May cause issues

Node Labels with Special Characters

Wrap labels containing special characters in quotes:

A["Label with (parens)"]
B["Label with / slash"]

Workflow

Step 1: Generate or Validate Mermaid Code

If the user provides a description rather than code, generate valid Mermaid syntax. Consult references/mermaid-syntax.md for full syntax details.

Step 2: Render SVG

Run the rendering script to produce an SVG file:

bun run scripts/render.ts --code "graph TD; A-->B" --output diagram --theme default

Or from a file:

bun run scripts/render.ts --input diagram.mmd --output diagram --theme tokyo-night

Alternative runtimes:

npx tsx scripts/render.ts --code "..." --output diagram
deno run --allow-read --allow-write --allow-net scripts/render.ts --code "..." --output diagram

This produces <output>.svg in the current working directory.

Step 3: Create HTML Wrapper