Ghost Font is a visual encoding that turns text into what looks like static. The idea is that a person can still read the hidden message while an AI model cannot. In the example shown here, creator Eric Lu says he tested it with Fable and GPT-5.6 Sol Ultra, and neither model decoded it correctly. I wanted to see how hard it would be to reproduce. I gave the example to Codex, asked it to build a version, and had it generate a screen recording of the result. The first working version took about fi

This PNG Can Attack AI Coding Agents