StyleMCP

Executable brand rules for AI models and agents. Keep every AI-generated message on-brand.

# What is StyleMCP?

StyleMCP validates and rewrites AI-generated text to match your brand voice. Use it as:

• REST API - Validate text from any application
• MCP Server - Direct integration with Claude and other AI agents
• CLI - Check copy in your terminal or CI/CD
• GitHub Action - Catch off-brand copy in pull requests

# Quick Start

# # API

curl -X POST https://stylemcp.com/api/validate \
  -H "Content-Type: application/json" \
  -d '{"text": "Click here to learn more!"}'

Response:

{
  "valid": false,
  "score": 65,
  "violations": [
    {
      "rule": "no-click-here",
      "severity": "error",
      "message": "Avoid 'click here' - describe the destination instead",
      "suggestion": "Learn more about our features"
    }
  ]
}

# # CLI

#  Install
npm install -g stylemcp

#  Validate text
stylemcp validate "Click here to learn more"

#  Validate file
stylemcp validate src/copy/homepage.json - -pack saas

#  Rewrite text
stylemcp rewrite "Please utilize our product" - -mode aggressive

# # MCP (Claude Desktop)

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "stylemcp": {
      "command": "npx",
      "args": ["stylemcp"]
    }
  }
}

Now Claude can validate and rewrite text using your brand rules.

# API Endpoints

| Method | Endpoint | Description |
|- -- -- -- -|- -- -- -- -- -|- -- -- -- -- -- --|
| POST | /api/validate | Validate text against brand rules |
| POST | /api/rewrite | Rewrite text to match brand voice |
| POST | /api/validate/batch | Validate multiple texts |
| GET | /api/packs | List available style packs |
| GET | /api/packs/{pack}/voice | Get voice guidelines |
| GET | /api/packs/{pack}/ctas | Get CTA rules |
| GET | /api/mcp/sse | MCP SSE endpoint |
| POST | /api/mcp/call | MCP tool calls |

# Style Packs

StyleMCP uses style packs - YAML files that define your brand rules.

# # Available Packs

| Pack | Best For | Key Features |
|- -- -- -|- -- -- -- -- -|- -- -- -- -- -- -- -|
| saas | B2B SaaS products | Professional, clear, helpful tone |
| ecommerce | DTC & retail brands | Friendly, conversion-focused, no pushy CTAs |
| healthcare | Medical & wellness | Compliant language, no cure claims, person-first |
| finance | Fintech & banking | Precise, risk-aware, no guaranteed returns |

# # Example: saas Pack

• Vocabulary: Prefer "use" over "utilize", "help" over "assist"
• Forbidden words: "synergy", "leverage", "cutting-edge", "game-changing"
• Patterns to avoid: "click here", "we're sorry for any inconvenience"
• CTA rules: Avoid "Submit", "Click here", "OK" - prefer "Save", "Create", "Sign up"

# # Pack Structure

packs/
  my-brand/
    manifest.yaml      #  Pack metadata
    voice.yaml         #  Tone, vocabulary, forbidden words
    copy_patterns.yaml #  Reusable copy templates
    cta_rules.yaml     #  Button/CTA guidelines
    tokens.json        #  Design tokens (optional)

# # Create Your Own Pack

#  Copy the default pack
cp -r packs/saas packs/my-brand

#  Edit the rules
nano packs/my-brand/voice.yaml

#  Use your pack
curl -X POST https://stylemcp.com/api/validate \
  -d '{"text": "Your text", "pack": "my-brand"}'

# # voice.yaml Example

tone:
  summary: "Friendly, clear, and helpful"
  attributes:
    - name: friendly
      weight: 0.8
    - name: professional
      weight: 0.7

vocabulary:
  rules:
    - preferred: "use"
      avoid: ["utilize", "leverage"]
    - preferred: "help"
      avoid: ["assist", "facilitate"]

  forbidden:
    - "synergy"
    - "paradigm shift"
    - "game-changing"

doNot:
  - pattern: "click here"
    reason: "Poor accessibility"
    suggestion: "Describe the destination"
    severity: error

  - pattern: "\\b(obviously|simply|just)\\b"
    isRegex: true
    reason: "Can make users feel stupid"
    severity: warning

# Self-Hosting

# # Docker

#  Clone the repo
git clone https://github.com/3DUNLMTD/stylemcp.git
cd stylemcp

#  Set up environment
echo "STYLEMCP_API_KEY=$(openssl rand -hex 32)" > .env

#  Run with Docker
docker compose up -d

#  Check health
curl http://localhost:3000/health

# # Manual

#  Install dependencies
npm install

#  Build
npm run build

#  Start server
npm start

# GitHub Actions

name: Brand Check
on: [pull_request]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Validate copy
        run: |
          npx stylemcp validate src/copy/ *.json \
            - -min-score 80 \
            - -format github

# Environment Variables

| Variable | Description | Default |
|- -- -- -- -- -|- -- -- -- -- -- --|- -- -- -- --|
| PORT | Server port | 3000 |
| STYLEMCP_API_KEY | API key for authentication | (none) |
| GITHUB_WEBHOOK_SECRET | GitHub webhook secret | (none) |

# MCP Tools

When used as an MCP server, StyleMCP provides these tools:

| Tool | Description |
|- -- -- -|- -- -- -- -- -- --|
| validate_text | Validate text against brand rules |
| rewrite_to_style | Rewrite text to match brand voice |
| get_voice_rules | Get voice and tone guidelines |
| get_copy_patterns | Get approved copy patterns |
| get_cta_rules | Get CTA guidelines |
| get_tokens | Get design tokens |
| list_packs | List available style packs |

# What Gets Validated?

The saas pack checks for:

# # Vocabulary

• Use simple words: "use" not "utilize", "help" not "assist"
• Avoid jargon: "synergy", "leverage", "paradigm shift"
• Avoid weak intensifiers: "very", "really", "extremely"

# # Patterns

• No "click here" (accessibility issue)
• No "we're sorry for any inconvenience" (corporate non-apology)
• No double "please" (sounds desperate)
• No starting with "Sorry" (lead with solutions)

# # CTAs

• Avoid generic: "Submit", "OK", "Yes/No", "Click here"
• Use specific actions: "Save", "Create", "Sign up", "Export"
• Max 4 words

# # Constraints

• Max 25 words per sentence
• No exclamation marks (in most contexts)
• First-person plural ("we", "our")
• Oxford comma

# License

MIT