Mermaid Config

/mermaid-config

User request: "$ARGUMENTS"

Task

Interactive config wizard: view and update plugin settings, or run a dependency health check.

Config file

All settings are stored in .claude/mermaid.json in the current project directory.

Default values (used when file does not exist):

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{
  "theme": "zinc-light",
  "output_directory": "./diagrams",
  "auto_validate": true,
  "auto_render": false,
  "output_format": "svg"
}

Process

Step 1: Resolve Plugin Path

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PLUGIN_DIR=$(find "$HOME/.claude/plugins/cache" -type d -name "mermaid" -path "*/skills/mermaid" 2>/dev/null | head -1)

If empty:

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PLUGIN_DIR=$(find "$HOME" -maxdepth 8 -type d -name "mermaid" -path "*/skills/mermaid" 2>/dev/null | head -1)

Use $PLUGIN_DIR in all subsequent commands.

Step 2: Read current config

If .claude/mermaid.json exists, read it. Otherwise use defaults above.

Step 3: If argument provided

If the user passed arguments (e.g. theme dracula or auto_render true), apply directly:

• Parse as {setting} {value}
• For theme: accept any of the 15 beautiful-mermaid theme names or custom
• Validate value is allowed (see options below)
• Update .claude/mermaid.json
• Confirm: "✅ {setting} set to {value}"
• Done.

Step 4: If no argument — show interactive menu

Display:

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Current config (.claude/mermaid.json):

  1. theme             → {current}   (zinc-light, github-dark, dracula, … 15 themes + custom)
  2. output_directory  → {current}
  3. auto_validate     → {current}   (true | false)
  4. auto_render       → {current}   (true | false)
  5. output_format     → {current}   (svg)
  6. custom theme      → configure themeVariables
  7. Run health check

What would you like to change? (enter 1-7)

Step 5: Handle selection

If 1 (theme):

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Available themes (beautiful-mermaid):

  Light:
   1. zinc-light           clean, neutral light
   2. github-light         GitHub-style light
   3. catppuccin-latte     warm pastel light
   4. nord-light           arctic light palette
   5. solarized-light      Solarized light
   6. tokyo-night-light    Tokyo Night light variant

  Dark:
   7. zinc-dark            clean, neutral dark
   8. github-dark          GitHub-style dark
   9. catppuccin-mocha     warm pastel dark
  10. nord                 arctic dark palette
  11. dracula              Dracula purple
  12. solarized-dark       Solarized dark
  13. tokyo-night          Tokyo Night
  14. tokyo-night-storm    Tokyo Night Storm variant
  15. one-dark             Atom One Dark

  16. custom               define your own colors

Enter 1-16:

Update theme in .claude/mermaid.json.

If 2 (output_directory): Ask for path. Update config.

Special values:

• "same" — save output in the same directory as the input file. Falls back to ./diagrams when there is no input file reference (e.g. text-only /mermaid-diagram calls).

If 3 (auto_validate): Toggle true/false. Update config.

If 4 (auto_render): Toggle true/false. Update config.

If 5 (output_format):

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Available formats:
  1. svg   — vector, only supported format

Enter 1:

Update output_format in .claude/mermaid.json.

If 6 (custom theme): Present the current values and prompt for each variable (leave blank to keep current):

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Custom theme colors (beautiful-mermaid format):

  bg      → {current or #ffffff}   background color (required)
  fg      → {current or #1a1a2e}   foreground/text color (required)
  line    → {current or #666666}   arrow and line color (optional)
  accent  → {current or #4a90d9}   accent/highlight color (optional)
  muted   → {current or #999999}   muted text color (optional)

Accept a hex color (#rrggbb) for each. Set theme to "custom" and save all entered values under themeVariables in .claude/mermaid.json.

Example saved config:

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{
  "theme": "custom",
  "themeVariables": {
    "bg": "#1a1b26",
    "fg": "#a9b1d6",
    "line": "#565f89",
    "accent": "#7aa2f7",
    "muted": "#565f89"
  }
}

If 7 (health check): See Health Check section below.

Step 6: Write updated config

Create .claude/ directory if it doesn't exist:

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mkdir -p .claude

Write updated settings to .claude/mermaid.json (merge with existing, don't overwrite unrelated keys).

Confirm: "✅ Config saved to .claude/mermaid.json"

Health Check

Run when user selects option 7.

Check 1: Node.js

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node --version 2>&1

✅ if v18.0.0 or higher | ❌ if not found or older → "Install Node.js 18+: https://nodejs.org"

Check 2: beautiful-mermaid (local node_modules)

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ls "$PLUGIN_DIR/scripts/node_modules/beautiful-mermaid" 2>/dev/null && echo "found" || echo "not found"

• ✅ if "found" → show version from $PLUGIN_DIR/scripts/node_modules/beautiful-mermaid/package.json

• ❌ if "not found" → auto-install:

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  npm install --prefix "$PLUGIN_DIR/scripts"
  

  Confirm: "✅ beautiful-mermaid installed"

Check 3: Render smoke test

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printf 'flowchart TD\n    A --> B' | node "$PLUGIN_DIR/scripts/render.js" /dev/stdin --output /tmp/mermaid-health-check.svg 2>&1

✅ if exit 0 and /tmp/mermaid-health-check.svg contains <svg | ❌ if error → show the JSON error message

Output format

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Mermaid plugin — dependency check

  ✅ Node.js v22.1.0      required runtime
  ✅ beautiful-mermaid     v1.1.3 — installed
  ✅ Render smoke test     SVG generated OK

Features:
  ✅ Generate diagrams    ✅ Validate    ✅ Render SVG
  ℹ️  PNG not supported   (use SVG — works everywhere Git renders markdown)