Cruncher

A zero-dependency scientific calculator server that exposes 43 math operations to Claude through stdio. Built without mathjs or the official MCP SDK to stay lightweight and educational. You get basic arithmetic, trig functions (degrees and radians), logarithms, statistical analysis (mean, median, variance, standard deviation), unit conversions across 8 categories, and scientific constants from physics and chemistry. It handles the classic JavaScript floating point problem (0.1 + 0.2) with integer scaling, validates inputs with custom schema checks instead of Zod, and uses worker threads with a 3-second timeout to kill runaway factorial calculations. Three tool tiers (minimal, standard, full) let you control context window usage. Reach for this when you need Claude to crunch numbers accurately without pulling in heavy calculation libraries.