Cal MCP

🚀 Cal Service

Cal Server is a simple mathematical expression calculation service built on the FastMCP framework, running in the Bun runtime environment. It uses the expr-eval library to parse and calculate mathematical expressions entered by users and interacts with the outside world through standard input and output (stdio).

🚀 Quick Start

Cal Server is a lightweight and efficient calculation tool that supports basic mathematical operations and built - in constants. It allows users to input mathematical expressions and get the calculation results.

✨ Features

• Expression Calculation: Supports users to input mathematical expressions and returns the calculation results.
• Built - in Constants:
  • E: Math.E in the Bun environment.
  • PI: Math.PI in the Bun environment.
  • true: Logical truth value.
  • false: Logical false value.
• Tool Name: cal.
• Parameters: Accepts a mathematical expression (of string type) (exp).

📦 Installation

Prerequisites

• Make sure you have installed the Bun runtime (the latest version is recommended).

Install via Smithery

To automatically install cal - mcp via Smithery:

npx -y @smithery/cli install @pwh-pwh/cal-mcp --client claude

MCP Client Configuration

"cal-mcp": {
      "name": "Calculation",
      "description": "",
      "isActive": true,
      "command": "bunx",
      "args": [
        "cal-mcp"
      ]
    }

Manual Installation

1. Clone the project repository:

   git clone <repository_address>
   

2. Navigate to the project directory and install dependencies:

   bun install
   

💻 Usage Examples

Basic Usage

1. Start the service:

   bun run index.ts
   

   The service will run through standard input and output (stdio).

2. Input a mathematical expression:

   • Example input: 2 + 3 * PI
   • Output: The calculation result (in string format).

3. Examples of supported expressions:

   • Basic operations: 2 + 2 → 4
   • Using constants: PI * 2 → 6.283185307179586
   • Complex expressions: E ^ 2 + 1 → 8.38905609893065

📚 Documentation

Dependencies

• fastmcp: Used to build MCP services.
• expr-eval: Used to parse and calculate mathematical expressions.
• zod: Used for parameter validation.

Important Note

⚠️ Important Note

The input expression must be a valid mathematical expression; otherwise, an error may be thrown. The service currently only supports interaction through stdio. The project uses the Bun runtime, so ensure that the commands are compatible with Bun.