Antigravity 2.2.1 & the agy CLI: What's New

Short version: Antigravity 2.2.1 shipped on June 25-26, 2026 with 19 improvements and 17 fixes. The headline is a built-in Guide skill that answers usage questions inside the editor, plus audio-file previews and new syntax highlighting for C++, Python, and Protobuf. Separately, Google's Go-based agycommand-line tool replaced the Gemini CLI for Pro and Ultra plans on June 18. This guide covers what changed, how to install and configure agy, and the trade-offs nobody puts in the release notes.

What Shipped in 2.2.1

First, get the version right. Google markets the wider product as Antigravity 2.0, but the actual editor build is 2.2.1. The official @antigravity account announced it on June 26 and described the release using the platform name, which is why some coverage mislabels it as a "2.0 update." The build is powered by Gemini 3.5 Flash.

The changelog lists 19 improvements and 17 fixes. Most are UI polish, but a handful change how you actually work. The table below is the short list worth knowing.

Do not confuse 2.2.1 with the earlier June build. The quota-screen redesign, PDF attachments, and the /btw slash command all landed in v2.1.4 on June 11, not in 2.2.1. If you skipped a release, you are getting both sets of changes at once.

The agy CLI

agy is Google's Antigravity command-line tool. It is written in Go for speed, runs agents asynchronously so you can drive several at once, and has been "available to everyone" since May 19. It identifies itself as "Antigravity CLI 1.0.0" and defaults to Gemini 3.5 Flash on the High tier. For a longer walk-through, see our Antigravity CLI deep dive.

Installation is a one-liner on each platform. After installing, run agy, sign in through your system keyring with Google Sign-In, and choose "Use a Google Cloud Project." For CI/CD, set the ANTIGRAVITY_TOKEN environment variable instead of an interactive login.

# macOS / Linux
curl -fsSL https://antigravity.google/cli/install.sh | bash

# Windows (PowerShell)
irm https://antigravity.google/cli/install.ps1 | iex

# then authenticate:
agy
# choose "Use a Google Cloud Project" and paste your secret key
# CI/CD: set ANTIGRAVITY_TOKEN instead of interactive login

Configuration lives in ~/.gemini/antigravity-cli/settings.json. This is where you turn on the cross-platform terminal sandbox (macOS sandbox-exec, Linux nsjail, Windows AppContainer), set the tool-permission mode, and allow or deny specific commands.

// ~/.gemini/antigravity-cli/settings.json
{
  "enableTerminalSandbox": true,
  "toolPermission": "request-review",
  "permissions": {
    "allow": ["command(git)"],
    "deny": ["command(rm -rf)"]
  },
  "defaultModel": "gemini-3.5-flash"
}

Plugins live under ~/.gemini/antigravity-cli/plugins/, each with a plugin.json and optional MCP config, hooks, skills, agents, and rules. Skills are just Markdown: drop .agents/skills/lint.md into your repo and it becomes the /lint command. Slash commands drive the rest of the workflow.

One thing to verify for yourself: model support. One popular guide (aibuilderclub) says agy can run Gemini 3.5 Flash, Gemini 3.1 Pro, Claude Sonnet, Claude Opus, and GPT-OSS 120B depending on plan tier. Another guide (explainx) says it is Gemini-only. That conflict is unresolved, so do not assume Claude routing works on your plan until you test it. On Pro and Ultra quotas, community reports say 3 to 5 parallel subagents run comfortably.

The Gemini CLI Sunset

On June 18, 2026, Google stopped serving Google AI Pro and Ultra plans through the Gemini CLI and the Gemini Code Assist IDE extensions. The replacement is agy. Enterprise and paid API-key access were not affected. Google published a migration guide at antigravity.google/docs/gcli-migration.

Here is the part that annoyed developers: the Gemini CLI was open source and supported the Agent Client Protocol (ACP). agy is neither. Swapping an open tool for a faster closed one is the sharpest criticism of the transition.

Whether that matters depends on you. If you never touched the Gemini CLI source and never used ACP, the sunset is a non-event and agy is simply faster. If you built on either, you are now on a closed-source dependency with no protocol escape hatch. A separate, less-publicized project, google/agents-cli, appeared around July 1 to manage agents across Antigravity, Claude, and Codex, so the tooling picture is still moving.

Antigravity + Claude Code

Because of the model-tier uncertainty above, many developers skip the debate and run Claude Code inside Antigravity directly. Antigravity ships a VS Code-style extension marketplace, and Anthropic publishes an official Claude Code extension for it. The setup takes under five minutes.

1. Open Antigravity
2. Open Extensions            (Cmd/Ctrl + Shift + X)
3. Search "Claude Code"
4. Install the official Anthropic extension
5. Add your Anthropic API key
6. Run /login

This puts Claude's models next to Gemini's in one editor, billed through your own Anthropic key. If you are weighing which agent to lead with, our Antigravity vs Claude Code comparison breaks down the trade-offs. The reverse direction (exposing Antigravity's models to Claude Code through a community proxy) also exists, but it is a preview-only, terms-of-service grey area, so treat it as an experiment rather than infrastructure.

Limitations

None of this is friction-free. The honest caveats:

If you hit crashes, SSH failures, or the aggressive context compaction people complain about, start with our Antigravity troubleshooting guide. And if the closed-source direction is a dealbreaker, our roundup of the best Antigravity alternatives for 2026 covers what else is worth trying.

FAQ

Glossary

Verdict

2.2.1 is a solid, unglamorous update. The Guide skill lowers the learning curve, audio previews and the new syntax highlighting are quality-of-life wins, and moving OAuth tokens into the OS keyring is quietly good security hygiene. Nothing here is a reason to switch editors, and nothing is a reason to avoid updating.

The agy CLI is the bigger story. It is genuinely fast, and the async multi-agent model is the right design for scripted work. But it arrived by retiring an open-source tool, and its model support is still murky. Adopt it for the speed; keep your eyes open about the lock-in.

Update to 2.2.1 now if:   you want the Guide skill, audio previews,
                          or C++/Python/Protobuf highlighting
Adopt the agy CLI if:     you script agents, run CI/CD, or want
                          async multi-agent runs
Stay cautious if:         you relied on the open-source Gemini CLI
                          or ACP (agy drops both)
Verify first:             whether your plan tier unlocks non-Gemini
                          models inside agy

Sources

Grouped by type. First-party sources first, then community posts and third-party guides. Version and date facts come from the official changelog and the @antigravity announcement.