Google opens Gemini 4 Carbon to the public, previews agent swarms in Antigravity

Google says Carbon is its strongest model so far and calls it a step beyond Argon, its other frontier model, which launched last month. Google says Argon remains the better choice for most software engineering and knowledge work, while Carbon targets harder problems such as complex multi-step coding and open-ended scientific research.

Carbon is available today through the Gemini API in Google AI Studio and Gemini for business for paying developers and enterprises. Google AI Ultra subscribers can also use it in the Gemini app, AI Mode in Search and Antigravity. It is unclear whether lower-tier subscribers or free users will get access later.

The introductory price is $2 per million input tokens and $10 per million output tokens. That price doubles at the end of November, and Google's benchmarks place Carbon behind Anthropic's Fable 5.2 on most metrics, though the article notes that vendors often choose favorable benchmarks.

Developers building agents on the Gemini API now have another frontier model option, priced below the rivals the article names on a per-token basis.

Per-token pricing may not reflect actual cost, since models can use different numbers of tokens for the same task, so teams should measure their own workloads before switching.

The swarm feature is only previewed, so agent builders should not plan around its behavior or availability yet.