Hundreds of repos.

Dozens of languages.

One mutation testing tool.

mutint tells you which of your tests would actually catch a bug — across your whole codebase, not one language at a time.

Why mutint

The catch has always been that mutation testing tools come one per language. Adopt it for Java, adopt a different one for C#. And when your solution uses multiple language, run multiple tools and try to reconcile it yourself.

mutint is one binary. Point it at a folder. Doesn't matter if it's a service, a monorepo, a whole org checkout. It finds every buildable unit underneath, in every language it knows, and reports one score in one format. Adding a language adds a plugin, not a second tool.

What you Get

One score, everywhere. Same operators, same math, same report, whether the unit is a .csproj or a Package.swift. A threshold you set once means the same thing in every pipeline.

Nothing to provision. A single native binary on macOS and Linux. No runtime on your build agents, no per-language tool to install and version.

Never touches your code. Every mutant is built and tested against a copy mutint owns. Your working tree stays clean, even if a run dies halfway.

Deterministic. Same inputs, same mutants, same order, every time. A score that moves means the tests moved.

Configured once, tuned anywhere. JSON config or CLI flags. The same directives either way. Narrow the operators, the files, or the test set per repo without forking your setup.

Get started

mutint is free. MIT licensed, every language, every repo, no seats to count and no score behind a paywall. Download the binary, point it at a folder, get a number.

Support and sponsored features

The tool is free. These aren't.

Support

Rolling mutation testing across hundreds of repos raises real questions: baseline failures in a gnarly build, tuning operators per team, wiring thresholds into pipelines that already exist. Buy a support agreement and those stop being your weekend.

Features

Need a language we haven't shipped, a report format your dashboard can read, or an integration with the CI you actually run? Fund it and it gets built — into mutint, under the same MIT license, maintained alongside everything else. You're buying priority, not a private fork.

Talk to sales

Tell us your languages and your repo count; we'll tell you what it takes.