Ultimath

Stop hallucinating numbers. An MCP server that runs every math expression through five independent numeric engines in parallel and returns all five results side by side — so when they disagree, you know the answer is numerically unreliable.

The five engines:

Engine	What it does
Multiprecision	High-precision arbitrary-digit arithmetic
Exact decimal	Exact base-10 arithmetic
IEEE-754 double	Standard hardware floating point
Interval	Rigorous lower/upper bounds (guaranteed enclosure)
Binary point	Arbitrary-precision binary, exact integer mantissa

Tools

• evaluate — evaluate an expression on all five engines and compare. Supports arithmetic, trig (sin, cos, tan), exp/log (exp, ln, log), roots and powers (sqrt, x^y), factorial, complex numbers (3+2i), alternate bases (0xFF, 0b1010), and constants (pi, e, golden ratio PHI).
• list_functions — list every function the engines expose (name, arity, category, description). Optionally filter by category.

Multiplication must be explicit: write 2*pi, 2*sin(x), (a+b)*(c+d). Adjacency is not a product (2pi is an error). Expressions are purely mathematical — no type casts or constructors; write a complex number as 1+2i.

Setup

1. Get a free API key at https://ultimath.ai.
2. Add the server to your MCP client config (example for Claude Desktop):

{
  "mcpServers": {
    "ultimath": {
      "command": "npx",
      "args": ["-y", "ultimath-mcp"],
      "env": {
        "ULTIMATH_API_KEY": "your_api_key_here"
      }
    }
  }
}

That's it — npx fetches and runs the server on demand.

Requirements

• Node.js ≥ 18
• An Ultimath API key (ULTIMATH_API_KEY)

Links

• Website: https://ultimath.ai
• Source: https://github.com/Flupke68/ultimath-mcp

Under the hood

Ultimath's engines build on FLINT/Arb, GMP/MPFR, MPFI, NTL and Boost — full credits at https://ultimath.ai/credits.

Privacy

Ultimath stores only a hash of your API key and basic usage metrics to run and secure the service; expressions are evaluated, not retained for training. Full policy: https://ultimath.ai/privacy/

License

MIT