The Short Version
At Google I/O 2026, Google launched Gemini 3.5 Flash — its strongest model yet for coding and autonomous agents — signaling a hard pivot from conversational AI to agentic AI. Alongside it came Antigravity 2.0, a complete rebuild of Google’s developer platform around multi-agent orchestration. Gemini CLI stops serving requests for AI Pro, Ultra, and free users on June 18, 2026 — so if you’re on it today, you have a deadline.
What Actually Happened
Google introduced Gemini 3.5, its latest family of models combining frontier intelligence with action, kicking off the series with Gemini 3.5 Flash — now generally available via Google Antigravity, the Gemini API in AI Studio and Android Studio, Gemini Enterprise Agent Platform, and rolling out globally in the Gemini app and AI Mode in Search. Onstage at I/O, Google engineer Varun Mohan demonstrated agents spawning off to work on separate components before converging to build a full operating system inside Antigravity — the company’s agentic development platform and IDE. Google also upgraded Antigravity to 2.0 with new capabilities to orchestrate and build agents, framing this year’s I/O around the transition from AI that assists to agents that independently navigate complex tasks. Gemini 3.5 Pro is already in internal testing, with a public rollout slated for June 2026.
Why Engineers Should Care
Antigravity 2.0 connects natively with Google AI Studio, Firebase, and Android, letting developers export projects from AI Studio directly to their local Antigravity instance while carrying over full context. Google is also launching Managed Agents in the Gemini API, allowing developers to spin up an agent with a single API call that reasons, uses tools, and executes code in an isolated Linux environment — no infrastructure setup required. For platform teams, the implications extend to cost modeling: while the per-token API price of Gemini 3.5 Flash rose compared to 2.5 Flash, and early developers are skeptical about net value, Google cut the AI Ultra subscription price to $100/month, bundling Managed Agents preview access and higher rate limits. If your pipelines currently shell out to Gemini CLI in CI, treat the June 18 deprecation deadline as P0 work.
The Technical Detail Worth Knowing
The new Antigravity CLI is built in Go, supports parallel execution, and is architecturally compatible with the Antigravity 2.0 desktop app. It retains Agent Skills, Hooks, Subagents, and Extensions — now rebranded as Antigravity plugins — and shares a unified agent harness with the desktop app, meaning all future core-agent improvements propagate automatically across both surfaces. The deeper change: Managed Agents provide process isolation in Linux sandboxes, making them practical for CI tasks and internal developer tooling — but audit and networking policies will be crucial when these agents access internal services. Google also shipped CodeMender, an AI security agent using Gemini’s reasoning to automatically find and fix critical code vulnerabilities — a capability Google framed as essential as agentic systems write an increasing share of production code.
What Comes Next
A few numbers from the keynote place the stakes in context: Google now processes over 3.2 quadrillion tokens per month, up 7× year-over-year, and the Gemini app is at 900 million monthly users. Gemini 3.5 Pro arrives next month for external developers. Google also confirmed its Gemini partnership with Apple, with a new more personalized Siri powered by Gemini set to release later in 2026. Community reaction on the Gemini CLI migration thread is running the predictable arc: confusion from solo developers, equanimity from enterprise teams whose access is unchanged.
Bottom Line
Google didn’t just announce a faster model — it restructured the entire developer contract around agents as the first-class primitive. If you’re building with the Gemini stack, Antigravity CLI is your new production surface and June 18 is your migration deadline.
KEY TAKEAWAYS:
- Migrate from Gemini CLI to Antigravity CLI before June 18, 2026; free, Pro, and Ultra consumer accounts lose access on that date — enterprise Code Assist licenses are unaffected
- Gemini 3.5 Flash is GA now across the API, Antigravity, and AI Studio; benchmark it against your current model on MCP Atlas tool-use evals before committing to a cost model, since per-token pricing rose while subscription pricing dropped
- Managed Agents (single-call API, isolated Linux sandbox, persistent state) are the architectural pattern to evaluate now for any long-running agentic workflow you’re currently building on raw LLM calls