calculator-mcp-server

# Calculator MCP Server A comprehensive calculator implemented as a Model Context Protocol (MCP) server using TypeScript. This server exposes a wide range of mathematical functions as MCP tools, allowing language models connected via MCP clients (like Claude for Desktop, Cursor, etc.) to perform calculations. ## Features Provides MCP tools for: * **Basic Arithmetic:** Addition, Subtraction, Multiplication, Division * **Exponents & Roots:** Power (`^`), Square Root * **Trigonometry:** Sine, Cosine, Tangent (input in radians) * **Inverse Trigonometry:** Arcsine, Arccosine, Arctangent, Arctan2 (output in radians) * **Degree/Radian Conversion:** Convert between degrees and radians * **Logarithms:** Natural Log (ln), Base-10 Log (log10), Log with arbitrary base * **Constants:** Pi (π), Euler's number (e) * **Factorial:** `n!` * **Percentage:** Calculate percentage of a number * **Modulo:** Remainder operation * **Absolute Value:** `abs()` * **Rounding:** Floor, Ceiling, Round to nearest integer ## Prerequisites * [Node.js](https://nodejs.org/) (v16 or higher recommended) * [npm](https://www.npmjs.com/) (usually included with Node.js) ## Installation 1. Clone the repository: ```bash git clone https://github.com/mvavassori/calculator-mcp-server.git ``` 2. Navigate into the project directory: ```bash cd calculator-mcp-server ``` 3. Install dependencies: ```bash npm install ``` ## Running the Server 1. Build the TypeScript code: ```bash npm run build ``` This compiles the code into the `build` directory. 2. Run the server: ```bash npm run start # OR directly using node: # node build/index.js ``` The server will start and listen for MCP connections via standard input/output (stdio). You should see a message like `Calculator MCP Server connected via stdio and ready.` printed to your terminal's *standard error*. Keep this terminal window open while using the server with Claude Desktop. ## Connecting to Clients (Claude Desktop Example) This server communicates using the MCP stdio transport. To connect it to Claude for Desktop: 1. **Find Claude Desktop's MCP Configuration File:** * **macOS:** `~/Library/Application Support/Claude/claude_desktop_config.json` * **Windows:** `%APPDATA%\Claude\claude_desktop_config.json` (You can paste this path into the File Explorer address bar). * **Linux:** `~/.config/Claude/claude_desktop_config.json` * If the file or the `Claude` directory doesn't exist, you might need to create it, or open Claude Desktop's Settings (`Claude Menu > Settings... > Developer > Edit Config`) which should create the file for you. 2. **Edit the Configuration File:** Open the `claude_desktop_config.json` file in a text editor. 3. **Add the Server Configuration:** Modify the file to include the `mcpServers` object with your calculator server entry. If the file was empty or didn't exist, its entire content should look like this: ```json { "mcpServers": { "calculator": { "command": "node", "args": [ "/home/marco/code/calculator-mcp-server/build/index.js" // IMPORTANT: Replace this path with the ACTUAL ABSOLUTE PATH // to the 'build/index.js' file on YOUR system. ] } // You can add other servers here under different keys, like: // "another_server": { ... } } } ``` **Notes:** * **CRITICAL:** Replace `/home/marco/code/calculator-mcp-server/build/index.js` with the correct *absolute path* to the `build/index.js` file within your cloned project directory on your computer. * On Windows, use double backslashes (`\\`) for the path separators, e.g., `"C:\\Users\\YourUser\\path\\to\\calculator-mcp-server\\build\\index.js"`. * The key `"calculator"` is just a name you give this server connection within Claude's config; it can be anything descriptive. * If the `mcpServers` object already exists, just add the `"calculator": { ... }` entry inside it, separated by a comma if other servers are present. 4. **Restart Claude for Desktop:** Ensure Claude for Desktop is fully closed and reopened for the new configuration to take effect. Claude for Desktop should now show the MCP tools icon (a hammer <img src="https://mintlify.s3.us-west-1.amazonaws.com/mcp/images/claude-desktop-mcp-hammer-icon.svg" style="display: inline; margin: 0; height: 1em;"/> ) and be able to use the calculator tools when you ask it to perform calculations. ## License MIT License