Prompts MCP Server

Prompts as Code – Treat your prompts like you treat your code: structured, parameterized, versioned, and reusable.

Why Prompts as Code?

As software engineers, we follow a simple principle:

If you repeat the same action three times, build a template.

The craftsman's principle. From ad-hoc to systematic. From repetition to tooling. And ultimately:

Repetition → Tooling → Quality

This applies to prompts too. Whether it's code reviews, test generation, or documentation cleanup – we repeat the same prompt structures with different contexts. Instead of retyping or copy-pasting variations, we can parametrize them.

The Dilemma

Prompts are often either:

• Too simple – providing little value beyond basic instructions
• Too detailed – requiring constant adaptation for each context, making them hard to reuse

The Solution

Parametrize your prompts – just like you extract variables from code:

---
name: code-review
description: Perform a code review with specific focus areas
arguments:
  - name: code
    description: The code to review
    required: true
  - name: focus
    description: Specific aspects to focus on (e.g., "performance", "security")
    required: false
---

Review the following code:

\`\`\`
{{code}}
\`\`\`

{{#if focus}}
Focus specifically on: {{focus}}
{{/if}}

Provide feedback on:

1. Code quality and maintainability
2. Potential bugs or issues
3. Performance considerations
4. Best practices

The structure stays stable. The variable parts ({{code}}, {{focus}}) are parameterized.

Why This Matters

🔄 Reusability through Variables
One prompt, many contexts. Parameterize the variable parts instead of rewriting for every use case.

📦 Version Control
Prompts live in your Git repository, not lost in chat history. Review, iterate, and rollback – like any other code.

🔧 Quality
When a prompt works better, refine it. When it degrades, roll back. Continuous improvement, just like code.

👥 Team Sharing
Share your best prompts with your team – not as screenshots or copy-paste, but as structured, documented artifacts.

Features

• 📝 Markdown-based prompts with YAML/JSON front matter
• 🎨 Handlebars templating for parameter substitution and conditionals
• 🔌 Dual transport support: stdio (local) and HTTP (remote)
• 🎯 Pre-shipped prompts including create-prompt to help you build new prompts
• 🔒 Type-safe with full TypeScript support
• ⚡ Lightweight and fast
• 🔄 Hot-reload user prompts from .prompts-mcp/prompts

Quick Start

Installation

# Clone the repository
git clone https://github.com/mrsimpson/prompts-mcp.git
cd prompts-mcp/packages/mcp-server

# Install dependencies
npm install

# Build
npm run build

# Run the server (stdio transport for Claude Desktop)
node dist/bin.js

Configure Claude Desktop

Add to your Claude config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "prompts": {
      "command": "node",
      "args": ["/absolute/path/to/prompts-mcp/packages/mcp-server/dist/bin.js"],
      "env": {
        "ENABLE_STDIO": "true",
        "LOG_LEVEL": "info"
      }
    }
  }
}

Restart Claude Desktop, and you're ready to use your prompts!

Create Your First Prompt

1. Create a .prompts-mcp/prompts directory in your project:

   mkdir -p .prompts-mcp/prompts
   

2. Add a prompt file (e.g., my-prompt.md):

   ---
   name: my-first-prompt
   description: A simple greeting prompt
   arguments:
     - name: name
       description: The name to greet
       required: true
   ---
   
   Hello {{name}}! Welcome to prompts-as-code.
   

3. Restart the server to load your new prompt

How It Works

1. Define prompts as Markdown files with YAML front matter
2. Parameterize variable parts using Handlebars syntax ({{variable}})
3. Store prompts in .prompts-mcp/prompts or use pre-shipped ones
4. Invoke prompts from your MCP client (e.g., Claude Desktop)
5. Parameters are substituted server-side before sending to the client

The server handles template rendering, validation, and transport – you just focus on writing great prompts.

User Guide

For detailed documentation, see:

📚 Complete User Guide – Full documentation including:

• Detailed configuration options
• Prompt file format and Handlebars syntax
• Running with stdio and HTTP transports
• Pre-shipped prompts reference
• Development guide
• Troubleshooting

🚀 Quick Start Guide – Get up and running in minutes

Example: Code Review Prompt

Here's a practical example of a reusable code review prompt:

---
name: code-review
description: Perform a comprehensive code review
arguments:
  - name: code
    description: The code to review
    required: true
  - name: language
    description: Programming language (e.g., "TypeScript", "Python")
    required: false
  - name: focus
    description: Specific review focus (e.g., "performance", "security")
    required: false
---

Please review the following {{language}} code:

\`\`\`
{{code}}
\`\`\`

{{#if focus}}
Focus specifically on: {{focus}}
{{/if}}

Provide feedback on:

1. Code quality and style
2. Potential bugs or issues
3. Performance optimizations
4. Best practices

Usage:

• Invoke code-review with code parameter
• Optionally specify language and focus
• Get consistent, structured code reviews

Pre-shipped Prompts

The server includes create-prompt – a meta-prompt that helps you create new prompts:

Arguments:

- purpose: What the prompt should accomplish
- target_audience: Who will use this prompt (optional)
- parameters: What parameters the prompt should accept (optional)

Use create-prompt to learn the structure and generate ready-to-use prompt files!

Architecture

prompts-mcp/
├── packages/
│   └── mcp-server/
│       ├── src/
│       │   ├── prompts/        # Prompt loading & validation
│       │   ├── server/          # MCP server factory
│       │   ├── transports/      # stdio & HTTP transports
│       │   └── config/          # Configuration management
│       ├── resources/
│       │   └── prompts/         # Pre-shipped prompts
│       └── test/                # Integration & unit tests
└── .prompts-mcp/
    └── prompts/                 # Your user prompts (auto-loaded)

Development

# Run all tests
npm test

# Run tests in watch mode
npm run test:watch

# Build
npm run build

# Lint
npm run lint

# Type check
npm run typecheck

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

License

MIT License – see LICENSE for details

Links

• 📦 GitHub Repository
• 📖 Model Context Protocol (MCP)
• 📝 Blog Post: Prompts als Code (German)

Status

⚠️ Alpha – This project is still in early development. Expect breaking changes and rough edges. Feedback and contributions welcome!

Release early in the open. 🚀