Google shuts down the open-source Gemini CLI on June 18, pushing devs to Antigravity CLI

Google is retiring the original Gemini CLI for most users on June 18, 2026 at 23:59 Pacific Time, and steering them toward a new replacement called the Antigravity CLI. The change was confirmed in an official notice on the gemini-cli GitHub repository and reported by outlets including Virtualization Review and The New Stack.

Who is affected

After the cutoff, accounts on Google AI Pro, Google AI Ultra, and the free personal tier of Gemini Code Assist will no longer be able to invoke the legacy Gemini CLI, and the same applies to the Gemini Code Assist IDE extensions for those tiers. Organizations with Gemini Code Assist Standard or Enterprise licenses, or those calling the models through paid Google Cloud API keys, keep access to the old CLI for now.

If you are a hobbyist or solo developer running the free or Pro tier, this is the group that needs to migrate before the deadline.

What is changing

The Gemini CLI launched as an open-source project and grew quickly, accumulating more than 100,000 GitHub stars and over 6,000 merged pull requests from hundreds of contributors. The Antigravity CLI that replaces it is a different kind of product: it is built in Go for faster, more responsive execution, supports asynchronous multi-agent workflows, and shares a backend with the Antigravity 2.0 desktop app. Crucially, the Antigravity CLI is not open source — it ships as a proprietary tool.

That shift is the source of most of the community pushback. Developers who contributed to an Apache-2.0 project are unhappy to see their work effectively fold into a closed-source successor. The original repository remains available under its open-source license, but it stops serving requests for the affected tiers on the 18th.

How to migrate

Google says the Antigravity CLI is close to a drop-in replacement and has published a migration guide at antigravity.google/docs/gcli-migration with FAQs and walkthroughs. Familiar concepts carry over — Agent Skills, Hooks, Subagents, and Extensions (now called Antigravity plugins) all have equivalents.

The catch is a handful of breaking behavior changes that bite anyone who renames the command mechanically: the default model, the streaming output format, the state directory location, and exit codes differ between the two tools. If you have scripts, CI jobs, or pre-commit hooks that shell out to gemini, test them against the new binary before the deadline rather than after.

Why it matters for people learning to build with AI

Command-line coding agents have become a default way to build with AI, and this is a reminder that the tooling layer is still volatile. A free, open-source entry point you relied on can be replaced on a few weeks' notice. The practical lesson is to keep your workflow portable — your prompts, your project instructions files, and your habits — so that swapping the underlying CLI is an afternoon of testing rather than a rebuild. If you are on an affected Gemini tier, set aside time before June 18 to install the Antigravity CLI and re-run your common tasks.