Breach: Grid City

The launch chapter has three challenges: hiding instructions in text an agent reads, a command-injection style task to pull secrets out of a system's data, and reading values from a shared memory region at specific offsets. It suits people who already know basic prompt injection and want agent-security scenarios that go past a single chat box.

It runs in a desktop browser; there is no mobile version. You create a profile with your email when you reach the second challenge, which saves progress and adds you to the leaderboard. Straiker plans new chapters every quarter.