Claude MCP Server — Starter Template

A clean, production-quality MCP (Model Context Protocol) server template for Claude Code and Claude Desktop. Includes 3 ready-to-use tool modules and a simple pattern for adding your own in minutes.

MCP is the skill that lets you turn Claude into a custom AI agent for any system. This is the template that shows you how.

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What is MCP?

MCP (Model Context Protocol) lets Claude call tools you define on your own machine. When Claude needs to search files, hit an API, or transform data — it sends a JSON-RPC request to your local server, your code runs, and Claude gets the result. Your data never leaves your machine.

Claude Code / Claude Desktop
          │
          │  JSON-RPC over stdio
          ▼
   ┌─────────────────┐
   │   server.py     │   ← MCP server (this repo)
   │   (MCP host)    │
   └────────┬────────┘
            │
     ┌──────┼──────┐
     ▼      ▼      ▼
   File    Web    Data
  Search  Fetch  Transform

The protocol is open, vendor-neutral, and supported natively in Claude Code CLI and Claude Desktop. Once you have a working MCP server, every tool you add is instantly available to Claude — no API wrappers, no cloud functions, no rate limits beyond your own.

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Included Tools

Tool	Module	What it does
search_files	file_search	Glob-search any directory; returns paths, sizes, timestamps
read_file_summary	file_search	Preview first N lines of a file + metadata and encoding
fetch_url	web_fetch	HTTP GET or POST — returns status code and response body
extract_links	web_fetch	Fetch a page, extract all anchor links as a list
json_to_csv	data_transform	Convert a JSON array of objects to a CSV file
csv_stats	data_transform	Analyze CSV columns: types, unique values, numeric ranges

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Quick Start

1. Clone and install

git clone https://github.com/JustDreameritis/claude-mcp-starter.git
cd claude-mcp-starter
pip install -r requirements.txt

Python 3.10+ required.

2. Configure for Claude Code

Add to your project's .claude/settings.json (or global ~/.claude/settings.json):

{
  "mcpServers": {
    "starter-tools": {
      "command": "python",
      "args": ["/full/path/to/claude-mcp-starter/server.py"]
    }
  }
}

See .claude/settings.json.example in this repo for the full schema.

3. Configure for Claude Desktop

Add to claude_desktop_config.json (location varies by OS):

{
  "mcpServers": {
    "starter-tools": {
      "command": "python",
      "args": ["/full/path/to/claude-mcp-starter/server.py"]
    }
  }
}

See claude_desktop_config.json.example for the full schema.

4. Start a conversation

Restart Claude Code (or Claude Desktop). The tools will appear automatically. Try:

• "Search for all Python files under /home/me/project"
• "Fetch https://news.ycombinator.com and extract all links"
• "Convert this JSON array to a CSV at /tmp/output.csv"

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Environment Variables

Copy .env.example to .env and adjust as needed. The server reads these at startup.

Variable	Default	Description
LOG_LEVEL	INFO	Logging verbosity (DEBUG, INFO, WARNING, ERROR)
MAX_FILE_SIZE_MB	10	Max file size for read/analyze tools
MAX_FETCH_SIZE_KB	500	Max response body size for fetch_url
ALLOWED_DIRECTORIES	/home,/tmp,/mnt	Comma-separated root paths file tools may access

All file tool calls are validated against ALLOWED_DIRECTORIES. Attempts to read outside these paths return a permission error — no silent failures.

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Project Structure

claude-mcp-starter/
├── server.py                       # MCP server entry point
├── tools/
│   ├── __init__.py
│   ├── file_search.py              # search_files, read_file_summary
│   ├── web_fetch.py                # fetch_url, extract_links
│   └── data_transform.py          # json_to_csv, csv_stats
├── docs/
│   └── SOW-template.md            # Upwork statement-of-work template
├── .claude/
│   └── settings.json.example      # Claude Code configuration template
├── claude_desktop_config.json.example
├── requirements.txt
├── .env.example
├── .gitignore
└── README.md

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Adding Your Own Tools

Each tool module follows the same three-part pattern. Creating a new tool takes about 10 minutes.

Step 1 — Create tools/my_tool.py

from mcp.types import Tool, TextContent

MY_TOOLS = [
    Tool(
        name="my_tool_name",
        description="One clear sentence describing what this tool does.",
        inputSchema={
            "type": "object",
            "properties": {
                "param1": {
                    "type": "string",
                    "description": "What this parameter is for.",
                },
                "param2": {
                    "type": "integer",
                    "description": "Optional count. Default: 10.",
                    "default": 10,
                },
            },
            "required": ["param1"],
        },
    ),
]


async def _my_tool_handler(arguments: dict) -> list[TextContent]:
    param1 = arguments.get("param1", "")
    param2 = int(arguments.get("param2", 10))

    if not param1:
        raise ValueError("'param1' is required.")

    # Your logic here
    result = f"Processed '{param1}' with count={param2}."
    return [TextContent(type="text", text=result)]


MY_HANDLERS = {
    "my_tool_name": _my_tool_handler,
}

Step 2 — Register in server.py

from tools.my_tool import MY_TOOLS, MY_HANDLERS

ALL_TOOLS.extend(MY_TOOLS)
TOOL_HANDLERS.update(MY_HANDLERS)

Step 3 — Restart Claude Code

That's it. Your tool is live.

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Architecture Notes

Why stdio transport?

MCP servers communicate with Claude via stdin/stdout using JSON-RPC 2.0. Claude Code spawns the server as a subprocess and manages the lifecycle. This means:

• No network port to open or firewall to configure
• Server starts and stops with Claude
• Logs go to stderr (visible in Claude Code's MCP debug output)
• Multiple MCP servers can run simultaneously without conflicts

Handler dispatch pattern

server.py uses a central dispatch table rather than decorating individual handlers per-tool. This keeps modules independent — each exports a plain dict — and makes it trivial to register, inspect, or disable tools at startup without touching tool code.

Error handling

All tool errors are caught in server.py's call_tool dispatcher and returned as TextContent responses. This means Claude always gets a useful error message instead of a protocol-level failure, and can reason about what went wrong and try an alternative approach.

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Running the Server Directly (for debugging)

python server.py

The server will wait for JSON-RPC input on stdin. You can test with raw JSON:

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}' | python server.py

Or enable debug logging:

LOG_LEVEL=DEBUG python server.py

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Tech Stack

• Python 3.10+
• mcp — Anthropic's official MCP SDK
• httpx — Async HTTP client for web fetch tools
• chardet — Encoding detection for file tools
• Standard library only for everything else (csv, json, glob, pathlib)

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Security Considerations

• File tools validate all paths against ALLOWED_DIRECTORIES before any I/O
• fetch_url enforces a response size cap (MAX_FETCH_SIZE_KB) to prevent memory exhaustion
• File read tools enforce a file size cap (MAX_FILE_SIZE_MB)
• HTTP requests use a 15-second timeout
• No shell execution, no subprocess spawning, no eval

For production team deployments, consider adding per-tool authentication and audit logging.

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Freelance / Upwork

Want to offer this as a service? See docs/SOW-template.md for a ready-to-use Statement of Work covering discovery, development, testing, and documentation phases — with tiered pricing from $150 to $800 depending on complexity.

MCP development is an emerging skill with very few practitioners and significant demand as teams start integrating Claude into their internal tooling.

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License

MIT — use it, fork it, sell services with it.

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Built by JustDreameritis