How Antithesis works

What’s software testing really about?

Fundamentally, testing stateful software is about exploring a very large state space thoroughly enough – because some of those states are bugs.

Antithesis does this for you by running multiple copies of your software in a simulation environment that’s much more hostile than prod.

Exploring your software

Running in Antithesis is like an extreme version of chaos engineering, where everything is running in our fault-filled environment – your software, your client, your checkers. We throw random inputs at it (as though we’re fuzzing), while filling the environment with a wide range of faults.

We don’t just throw random inputs at the system – we have an intelligent guidance component (it uses RL, but you can tell your boss it’s AI) that constantly drives the platform to seek out new system states.

This creates a multiverse of branching execution paths in every Antithesis test. You can think of these as tens of thousands of alternate universes. In one universe, the network partitioned at time=t, and in many others, it didn’t.

Spotting bugs

To tell if a particular state is a bug, Antithesis relies on properties you define.

Instead of writing a vast test harness, you simply state that your system should have certain properties, and Antithesis checks whether they’re ever violated.

For example: You could write a hundred tests that each cover a different execution path and check whether your program crashes. But it’s simpler and more powerful to write a single statement that the program should never crash!

And because properties are long-lived, you never have to update your tests (unless you decide that you do want, e.g. to stop checking for race conditions).

Fixing bugs

The Antithesis environment is fully deterministic. This makes every bug we find perfectly reproducible, so you’ll never waste time trying to reproduce a flaky bug again.

Determinism enables us to provide detailed artifacts and powerful, one-of-a-kind debugging tools, like a deterministic time-traveling debugger.

What next?

Ready to get started? contact us at support@antithesis.com or ask on our Discord to request a container registry and credentials. Once you have those, you can dive right in/