Build apps agentically with the combined power of Gemini 3 and Claude Opus 4.5 for free in Google Antigravity. Designed for burst creatives, this standalone IDE routes routine tasks to Gemini 3 and complex reasoning to Opus 4.5, offering a weekly quota of ~50 high-level Opus requests without API fees. The agentic system autonomously executes terminal commands and verifies `localhost` deployments, replacing paid tiers of Cursor for weekend hobbyists.