Did Google’s AI agents really build an operating system for $916?

At Google’s developer conference earlier this week, the company launched its latest model, Gemini 3.5 Flash, alongside a new agent app, Antigravity 2.0. To showcase what this new agent setup is capable of, Google claimed that a team of agents had built an entire operating system. The effort reportedly required only a single prompt, cost only about $900 in API fees, and was carried out by a few dozen subagents working together.