Claude Opus 5.5 changelog

Full Claude Platform available on Google Cloud (Anthropic managed)

Claude Models on Google Cloud (Anthropic managed) is generally available with US and Global endpoints. It gives Google Cloud customers the full Claude Platform feature set with Google Cloud IAM, billing and commitment drawdown. Fable 5.1, Opus 5.5, Sonnet 5.5 and Haiku 5.5 are available, and fast mode for Opus 5.5 costs $8 / $40 per million input and output tokens there.

Who is affected:

Teams that buy Claude through Google Cloud and want features that the Google-managed offering lacks.

What to do:

No action needed. Google Cloud customers who need same-day Claude API features can switch to the Anthropic-managed offering.

Fast mode for Claude Opus 5.5 leaves research preview

Fast mode on Opus 5.5 no longer needs the beta header or an access request, gets a default rate limit in the Start, Build and Scale tiers, and is available on Microsoft Foundry. Fast mode costs $8 / $40 per million tokens.

Antigravity 2.24 adds model choice for automations and Claude 5.5 models through Vertex AI

Antigravity app 2.24.0 lets automations run on Flash Lite, Flash or Pro, adds /compact and a redesigned side panel. With Application Default Credentials sign-in, the model picker offers Claude Opus 5.5 and Claude Sonnet 5.5 when the Google Cloud project has access to them.

Claude Opus 5.5 released at a lower price than Opus 5

Claude Opus 5.5 launched at $4 / $20 per million tokens (Opus 5 is $5 / $25), with cache reads at $0.20 per million tokens and always-on adaptive thinking.

Who is affected:

Developers and subscribers using Claude Opus 5.

What to do:

Test claude-opus-5-5. Remove any thinking disabled setting and forced tool_choice first.

Claude Opus 5.5 available in GitHub Copilot

Claude Opus 5.5 is available on Copilot Pro+, Max, Business and Enterprise at provider list price. GitHub says it resolved tasks about as well as Opus 5 with significantly fewer steps and tokens.