Gemini 4 Carbon targets complex bugs, but public access must wait

Google announced Gemini 4 Carbon on October 28, 2026, with a focus on cybersecurity defense and sustained engineering work. Access starts with selected cyber defenders, so this is not a general release that developers or Gemini users can switch on today.

Following a bug through a large codebase

Google says its internal teams have seen Carbon work for days, persisting through dead ends while tracing subtle bugs to their root causes and patching them in large codebases and low-level systems.

For game and tool creators, the potential is help connecting a bug’s symptoms to the code that needs fixing. Those internal examples do not promise a particular runtime or guarantee that an agent will successfully finish development work unattended.

Finding a flaw and fixing it are different tests

Google reports scores of 88.2% on SEC-bench Pro for finding vulnerabilities, 54.8% on ExploitGym for validating exploitability, and 71.0% on CWE-bench for patching.

According to Google, these external benchmark evaluations ran without guardrails. Each score covers a different part of security work under those test conditions; none should be treated as a real-world success rate or independent assurance of security.

Trusted partners come before wider access

Google plans to expand access gradually to additional trusted partners through its Fairwind Program. Developers, businesses and consumers are due to follow, but Google has not given a firm date for that wider availability.

The introductory token rates will not last indefinitely

Google lists introductory launch pricing of $2 per million input tokens and $10 per million output tokens. After the introductory period, the rates become $4 per million input tokens and $20 per million output tokens. No end date for the introductory period is stated.

Cached input is listed at 95% off the base input-token price. These are API usage rates for tokens—the chunks of text a model processes or generates—not a consumer subscription. The announced pricing does not mean unrestricted API access is available now.