Character Counter MCP Server - Python Quickstart
A simple example of creating an MCP server using FastMCP and Python, designed to work with Smithery.
What This Does
This server provides a character counter tool called count_character that counts how many times a specific character appears in a given text. You'll test it using the Smithery Playground for interactive development.
Prerequisites
- Python 3.12 or higher
- A Python package manager (uv recommended, but pip, poetry, etc. also work)
- Node.js and npx (optional, for Smithery Playground)
Quick Start
-
Clone the repository:
git clone https://github.com/smithery-ai/smithery-cookbook.git cd smithery-cookbook/servers/python/quickstart -
Install dependencies:
With uv (recommended):
uv syncWith poetry:
poetry installWith pip:
pip install -r requirements.txt -
Run the server:
You have two options:
Option A: Just run the server
# With uv uv run smithery dev # or use the shorter script alias: uv run dev # With poetry poetry run smithery dev # or use the shorter script alias: poetry run dev # With pip (after installing dependencies) smithery devThis starts the MCP server on
http://localhost:8081and keeps it running.Option B: Run server + open playground (recommended for testing)
# With uv uv run smithery playground # or use the shorter script alias: uv run playground # With poetry poetry run smithery playground # or use the shorter script alias: poetry run playground # With pip (after installing dependencies) smithery playgroundThis starts the MCP server AND automatically opens the Smithery Playground in your browser where you can:
- Interact with your MCP server in real-time
- Test the
count_charactertool with different text and characters - See the complete request/response flow
- Debug and iterate on your MCP tools quickly
Testing the Character Counter
Try asking: "How many r's are in strawberry?"
- Deploy to Smithery:
To deploy your MCP server:
- Push your code to GitHub (make sure to include the
smithery.yaml) - Connect your repository at https://smithery.ai/new
- Push your code to GitHub (make sure to include the
Your server will be available over HTTP and ready to use with any MCP-compatible client!
Stopping the Server
Press Ctrl+C in the terminal to stop the server.