mcp-abacus
A calculator for the artificial minds — because we know their needs are different.
People reach for a calculator to get a number. A language model reaches for one to get a number it can trust and reason about: Was this exact, or rounded? At what scale? Would a wider type have held more digits? Does this overflow the way the production code will? A floating-point answer that merely looks precise is worse than no answer — it launders a rounding error into a confident claim.
mcp-abacus is built for that caller. It does type-faithful calculation: you
pick a numeric type/mode (fixed-point, IEEE-754 double, exact rational, complex) and the
whole expression behaves exactly as that type would in real code — it rounds
where the type rounds, stays exact where the type is exact, and carries the
result onward bit-for-bit. Every answer comes back labelled with its own
precision verdict (exact vs inexact, rounded to N decimals), so the model
never has to guess whether a result is the true value. It does not approximate a
type; it calculates using that type.
