Model Context Protocol low risk

Cal

Cal Server is a lightweight mathematical expression evaluator using stdio for input/output, offering basic arithmetic and constants within a Bun runtime environment.

Connections & Capabilities

Connects To

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Capabilities

readexec

Quickstart

Install

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

Exposed MCP Tools (1)

safe

cal

Evaluates a mathematical expression provided as a string.

Read-only execution of mathematical expressions with no side effects beyond computation.

Safety Assessment

Cal Server is generally safe for evaluating mathematical expressions due to its sandboxed environment and lack of external dependencies. However, it's crucial to monitor resource usage to prevent denial-of-service attacks and keep the `expr-eval` library updated to mitigate potential vulnerabilities. It is safe to use with trusted inputs.

No network access required
Operates via standard input/output (stdio)
Expression evaluation is sandboxed by `expr-eval`
No file system access
No external API calls

Potential for denial-of-service if expressions are excessively complex
Limited error handling could expose unexpected behavior
No built-in rate limiting
Reliance on `expr-eval` library for security; vulnerabilities in the library could be exploited
No authentication or authorization