The open-source project imrobot flips the usual CAPTCHA model around. Instead of testing whether a visitor is human, it generates chains of operations such as string reversal, Caesar shifts, XOR, and hashing that software agents can execute quickly but humans would find impractical by hand.

Developer Leo Pechnicki presents it as a way to gate agent-only APIs and other services intended specifically for automated clients. This time, humans are the visitors the verification gate is designed to reject.