Google made Gemini 4 Carbon generally available on the paid Gemini API on November 10 and began rolling it out to Google AI Ultra subscribers in the Gemini app, AI Mode in Search and Antigravity. Access had been limited to a group of cybersecurity defenders through Google’s Fairwind program after the October 28 announcement.
Developers can use gemini-4-carbon through the paid API in Google AI Studio and Android Studio. Google is also making it available to enterprises through Gemini for business. Google designed Carbon for long software and research tasks that require several rounds of work. It says Carbon uses more tokens than Gemini 4 Argon, which it still recommends for most software engineering and knowledge work.
What the API costs
Through November 30, standard requests cost $2 per million input tokens and $10 per million output tokens. On December 1 those rates rise to $4 and $20. Output billing includes thinking tokens. Cached input costs $0.10 per million tokens through November 30 and $0.20 from December 1. Carbon supports automatic caching, but developers cannot create an explicit cache. There is no free API tier for Carbon.