Google AI Studio Build Mode reportedly runs on Gemini 4 Argon and Antigravity

A user says Google AI Studio Build Mode now pairs Gemini 4 Argon with the Antigravity agent harness to manage project state, edit multiple files and test changes. They describe a React frontend and Node.js backend, visual edits, two-way GitHub sync and one-click deployment to Cloud Run. They also say the Google Cloud Starter Tier lets users publish up to two full-stack apps without setting up a GCP project or billing.