Google's agentic coding tool Antigravity rolled out Anthropic's Claude Opus 5.5 and Sonnet 5.5 this week, but access is limited to full-price Google AI Pro and Ultra subscribers. According to notes posted in the Antigravity user community, starting November 2, every third-party model inside Antigravity will be restricted to those two paid tiers.
Older models are being retired the same day. Based on a list compiled from public reports, Claude Opus 4.6, Sonnet 4.6, and OpenAI's open-weight GPT-OSS-120B will all be pulled on November 2. Google's own Gemini 3.8, 3.7, 3.6 Flash, and 3.1 Pro are unaffected — they remain available across all plans, with no retirement date attached.
Who Gets Locked Out
The free tier isn't the only one excluded. The reported list also names Free, AI Plus, and the enterprise Enterprise plan; even Pro accounts are shut out of the 5.5 lineup if they were activated through a promotion, a discount, or a free trial. What happens to student plans remains unconfirmed.
Users in the community have already started asking specifically how Pro accounts activated through third-party channels will be treated, and the thread has no official reply yet. Based on what's known so far, the dividing line appears to be whether an account paid full price — not which tier its label says it's on.
Anthropic positions the two models differently: Opus 5.5 is built for long coding sessions and knowledge work, while Sonnet 5.5 balances speed and capability. Sonnet 5.5 launched on September 28 and made it into Antigravity in under a week.
Gemini App Tightens Access Too
Antigravity's change isn't an isolated move. Google also announced new tiers for the Gemini app: starting October 9, users without a subscription will be limited to the smallest Flash-Lite model; Google AI Plus subscribers get Flash-Lite and Flash; only Pro and Ultra subscribers can access the Pro model and Deep Think reasoning mode. Gemini 4 Argon only launched on September 30, and within days the free tier was pushed down to the lightest model available.
Taken together, the two moves point the same direction: free compute is shrinking, and new models are going to full-price subscribers first.
Developers in Mainland China Feel It Most Directly
Discussion in Antigravity's Chinese-language community suggests that developers there commonly get access through student discounts, free trials, or Pro accounts activated via third-party resellers — all categories that now fall into the excluded or unconfirmed bucket. Under the current rules, these accounts will lose access to the 5.5 lineup after November 2, and the 4.6 models they could previously use will be retired at the same time, leaving Gemini as essentially the only option once third-party models are cleared out.
For anyone who wants to keep using Claude inside Antigravity, the straightforward path is subscribing to Pro or Ultra at full price. Developers who just want Claude for coding can also go directly through Anthropic's own Claude Code or API — but Anthropic doesn't offer services to mainland China, and Hong Kong users have recently seen batches of accounts suspended too, so developers there run into account and payment hurdles no matter which route they take.
Google hasn't explained whether the tightening is about compute costs or terms tied to its partnership with Anthropic. Third-party model usage is billed by volume to the model provider, so the higher the share of free and discounted accounts, the more Google ends up covering — that's a plausible business explanation, but neither company has disclosed how the partnership is actually priced.
Sources: Google Antigravity user community, Nokia Power User, CocoLoop, Neowin, TechCrunch; the list of available models, retirement date, and plan scope are compiled from public reporting.