Calculator MCP Server

A TypeScript-based MCP server that implements a robust calculator with precise decimal arithmetic. This server demonstrates core MCP concepts by providing arithmetic operations with support for multiple operands and configurable precision using Decimal.js.

These functions take an array of at least two numbers and return a single numerical result.

- add- Adds an array of numbers.
- subtract- Subtracts numbers sequentially from the first.
- multiply- Multiplies an array of numbers.
- divide- Divides numbers sequentially. Handles division by zero.

These functions operate on arrays of numbers and return an array of results. Theanglesinput requires at least one number.

- Basic Trigonometry:sin,cos,tan

- Input:angles(array of numbers),mode('radians' or 'degrees', defaults to 'radians').

- set_precision- Configures decimal precision for all subsequent calculations.

- Takesprecisionparameter as the number of decimal places.

To use with Claude Desktop, add the server config:

On MacOS:~/Library/Application Support/Claude/claude_desktop_config.jsonOn Windows:%APPDATA%/Claude/claude_desktop_config.json

{ "mcpServers": { "Calculator": { "command": "/path/to/calculator-mcp/src/index.ts" } } }

Or for Cline VSCode extension, add a modified version of this to your MCP config file:

"Calculator": { "autoApprove": [ "add", "subtract", "multiply", "divide", "set_precision" ], "disabled": true, "timeout": 60, "type": "stdio", "command": "bun", "args": [ "/path-to-your/calculator-mcp/src/index.ts" ] }

To run the MCP server using Docker, you should first build the image using:

Followed by adding this to the (Cline) MCP config file:

"Calculator (docker)": { "autoApprove": [ "add", "subtract", "multiply", "divide", "set_precision" ], "disabled": false, "timeout": 60, "type": "stdio", "command": "docker", "args": [ "run", "--rm", "-i", "calculator-mcp" ] }

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using theMCP Inspector, which is available as a package script:

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