Calcport MCP Server

calcport

calcport does arithmetic safely. Its centrepiece is an expression evaluator that understands the usual operators, parentheses, a handful of functions, and the constants pi and e — and nothing else. The evaluator is a hand-written parser, so an expression can never turn into code execution, a shell call, or a property lookup. Around it sit four single-purpose operations for callers that just need one sum, difference, product, or quotient.

Install

npx @reneturcios/calcport calculate "2+3*4"

Or run the container image:

docker run -i ghcr.io/cloudcorprecords/calcport

The container defaults to the MCP server (see below). Pass CLI arguments to use it as a CLI instead.

CLI

# Evaluate an expression
calcport calculate "sqrt(3^2 + 4^2) + pi"
# 8.141592653589793

# Single operations
calcport add 2 3          # 5
calcport subtract 10 4    # 6
calcport multiply 2.5 4   # 10
calcport divide 7 2       # 3.5

# Machine-readable output
calcport calculate "2^10" --json
calcport add 2 3 --json

calcport --version

Expressions may use + - * / % ^, parentheses, unary minus, the functions sqrt, abs, floor, ceil, and round, and the constants pi and e. ^ is right-associative, so 2^3^2 is 512.

Exit codes: 0 on success, 1 when a calculation cannot be done (division by zero, a malformed expression — the error says why), 2 for usage errors.

MCP server

One bin serves both faces. The mcp subcommand starts a stdio MCP server:

npx -y @reneturcios/calcport mcp

MCP client configuration:

{
  "mcpServers": {
    "calcport": {
      "command": "npx",
      "args": ["-y", "@reneturcios/calcport", "mcp"]
    }
  }
}

Tools

Development

npm install
npm run build   # tsc -> dist/
npm test        # node test runner over test/*.test.ts, no network
npm run dev     # run the CLI from source via tsx

License

MIT — see LICENSE.