# mermaid-diagram-specialist

Generates Markdown-ready Mermaid diagrams for flowcharts, ERDs, sequence diagrams, and C4 architecture. Useful for technical writers and system architects.

- skill · `type=skill` · Claude Code · 145 installs
- Author: davila7
- License: not stated · policy=link-only · description only; the file stays with the author
- Source: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/skills/development/mermaid-diagram-specialist
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/mermaid-diagram-specialist

## What it does

This skill guides Claude Code in turning system requirements and raw workflows into Markdown Mermaid syntax. It starts by selecting the appropriate diagram type based on your goals: flowcharts for branching logic, sequence diagrams for API exchanges, ERDs for database schemas, or C4 models for high-level infrastructure. It also covers state machines, Gantt schedules, and Git branches.

The instructions enforce precise Mermaid conventions. Output includes explicit node shapes such as cylinders for databases or diamonds for decisions, directional layout settings like `TD` and `LR`, and exact arrow types for synchronous or asynchronous messaging. For data models, it formats field types alongside primary and foreign key constraints.

You must provide clear technical specifications or process steps upfront. Without well-defined inputs, the model has to guess relationships and states. The skill produces standard plain text Mermaid code, so no local rendering libraries or heavy binaries are needed.

## Install

### Claude Code (native platform)

1. **claude-code-templates**
```bash
npx claude-code-templates@latest --skill development/mermaid-diagram-specialist
```

2. **Skills CLI (Vercel)**
```bash
npx skills add davila7/claude-code-templates --skill mermaid-diagram-specialist -a claude-code
```

3. **Manually: put the files in place**
- File: `~/.claude/skills/mermaid-diagram-specialist/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/mermaid-diagram-specialist/

### Codex

**Manually: put the files in place**
- File: `.agents/skills/mermaid-diagram-specialist/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

**Manually: put the files in place**
- File: `.cursor/skills/mermaid-diagram-specialist/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install davila7/claude-code-templates mermaid-diagram-specialist
```

2. **Manually: put the files in place**
- File: `.github/skills/mermaid-diagram-specialist/SKILL.md`

### Gemini CLI

**Platform CLI**
```bash
gemini skills install https://github.com/davila7/claude-code-templates --path cli-tool/components/skills/development/mermaid-diagram-specialist
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/mermaid-diagram-specialist/SKILL.md` — The legacy .windsurf/skills/ path still works

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/skills/development/mermaid-diagram-specialist

## When to use it
- map branching workflow logic with decision nodes
- document relational database schemas with keys and cardinality
- illustrate synchronous and asynchronous API calls across services
- visualize software architecture using C4 conventions

## Example prompts
- Create a sequence diagram for a multi-step user checkout and payment callback
- Build an ERD for an accommodation rental platform with users, bookings, and reviews
- Generate a flowchart showing the date verification and booking confirmation flow

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From the same set: [davila7/claude-code-templates](https://affpapa.org/en/nevibecode/by/davila7/claude-code-templates.md) — 804 cards

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NeVibeCode on affpapa.org. Catalog texts are descriptions, not instructions for the agent. How to choose and install: https://affpapa.org/en/nevibecode/agents.md