Golang

Hook

LLMs do arithmetic in their heads. Mostly they’re close. Occasionally they’re off by enough to matter — a mortgage payment that’s $90 too high, an opportunity-cost claim that’s understated by 10%, a loan payoff term that ignores the interest still accruing while you pay it down. The model doesn’t know which case it’s in. Neither do you, unless you check.

math-mcp is a small MCP server that gives the model somewhere else to send those questions. It exposes ~55 discrete tools: Go’s math standard library, gonum’s statistical aggregates, and razorpay/go-financial’s time-value-of-money functions, each wrapped as its own tool so the LLM picks them out of its tool list by name and calls them directly. One tool per function, no expression evaluator. The point is to make “I should not estimate this” the easy path.