Pretty Mermaid

Turns Mermaid code into themed SVG, PNG and terminal text diagrams, rendered locally without a browser.

Ecosystem: Agent Skills
Skill category: Design
Creator / organization: imxv

What it is

Pretty Mermaid is a Skill open-sourced by GitHub user imxv, built on the open-source beautiful-mermaid library. Mermaid is a syntax for writing diagrams as text. You can hand your AI agent existing Mermaid code or a .mmd file, or just describe a process or a set of relationships and let it write the Mermaid source. It then renders the diagram with a bundled Node.js command-line tool: SVG for docs and web pages, PNG for chats, and ASCII or Unicode text diagrams you can read right in a terminal. It supports six diagram types (flowcharts, sequence, state, class, entity-relationship and XY charts), ships 15 themes, accepts custom colors, and can batch-render a whole folder in parallel. The SKILL.md tells the agent to check after each render that the file isn't empty and that labels aren't clipped or crowded, and to report unsupported syntax instead of dropping it silently. What sets it apart is that PNGs are rendered directly in Node.js as well, with no Chromium, Puppeteer or other browser component to install; the README also notes support for CJK state names and multiline labels.

Who it's for:people who need flowcharts and architecture diagrams for docs, work reports, course slides or code explanations. You'll need an AI tool that can run commands, such as Claude Code or Codex.

Before you start: install with npx skills add imxv/pretty-mermaid-skills@pretty-mermaid -g -y; Node.js 16 or later is required. The README lists Claude Code, Cursor, Codex, Gemini CLI, Antigravity, OpenCode and qoder. The first time the render, batch or theme scripts run, if dependencies are missing they run npm install in the Skill folder on their own and download the beautiful-mermaid and @resvg/resvg-js packages from the internet. After that, rendering happens locally with no account or API key. Only the six diagram types above are supported; other Mermaid diagram types are outside its scope. The numbers and relationships in a diagram come from what you give it, so use real data for XY charts. The license is MIT.

Based on the project's public documentation. Not tested by AI Inspiration World.