Claude Opus 5.5 and Claude Sonnet 5.5 became available in Google Antigravity, including its command-line tools and development-environment extensions.

Google Cloud customers can select the Claude models after administrator enablement. Google positions Claude Opus 5.5 for complex work and Claude Sonnet 5.5 as a faster, lower-cost complement. The model selection operates within a unified enterprise billing and security boundary.

Availability spans several developer interfaces. Supported surfaces include Antigravity 2.0, the Antigravity command-line interface (CLI), and integrated development environment (IDE) extensions for VS Code, JetBrains IntelliJ, and Visual Studio. Administrators can also select Google models, including Gemini 3.8 Flash and Gemini 4 Argon.

Google describes cross-model verification as one engineering pattern. A developer can use one model family to plan and implement a change, then another to review it against requirements and tests. The workflow can run interactively or through automated subagents, including a one-shot `/model` check in the CLI.

A second pattern assigns model tiers to different subtasks. Antigravity’s subagent configuration supports `inherit`, `flash`, and `pro` tiers, with inherited models used for deeper reasoning and Flash subagents assigned high-volume search, classification, and triage. The supplied excerpt does not provide model prices or measured latency comparisons.