Gemini CLI Is Dead on June 18 — Should You Switch to Antigravity CLI or Claude Code?

Gemini CLI stops serving requests on June 18, 2026. That is two days from now. If you are one of the developers who relied on it, you have a decision to make fast: migrate to Antigravity CLI, Google’s official replacement, or switch to Claude Code. Both are strong tools. But they are very different, and the decision comes with context that most migration guides are not covering.

Here is what you actually need to know before June 18.

What Is Happening and Who Is Affected

Google announced the Gemini CLI shutdown at Google I/O on May 19, 2026. Starting June 18, requests from Google AI Pro subscribers, Google AI Ultra subscribers, free-tier Gemini users, and individual Gemini Code Assist users will stop being served. Enterprise Gemini Code Assist Standard and Enterprise license holders are explicitly exempt and keep access indefinitely.

That enterprise carve-out is worth noting. Simon Willison observed on Hacker News that the “technical necessity” for shutting down Gemini CLI appears to evaporate when a large enough contract is involved. The double standard did not go unnoticed by the developer community.

The migration Gemini CLI entered maintenance mode in April 2026, with new features frozen and in-terminal banners urging users to switch. The official migration path leads to Antigravity CLI. Google estimates the process takes under 10 minutes for most setups.

The Open-Source Bait-and-Switch Nobody Is Talking About Enough

Before comparing the two tools, this needs to be said plainly: Gemini CLI was Apache 2.0 open source. It had over 100,000 GitHub stars and more than 6,000 merged community pull requests. Developers contributed real work to an open-source project they trusted.

Antigravity CLI, the official replacement, is closed source. The GitHub repository contains only a changelog, a README, and an animated GIF. No source code.

Tech Times ran the headline: “Furious Developers Accuse ‘Sickening’ Google Gemini CLI Bait-and-Switch.” The Register called it Google “nudging devs toward closed-source AI.” The community anger is legitimate. If that matters to you when choosing a tool, it should factor into your decision.

Claude Code is also closed source, for what it is worth. If open-source is a hard requirement, neither tool satisfies it. In that case, look at OpenClaw or NanoClaw instead.

Antigravity CLI: What It Is and How It Works

Antigravity CLI (binary: agy) is the CLI surface of Google’s broader Antigravity 2.0 platform, which also includes an IDE, a desktop app, and a Python SDK. It is written in Go, starts in milliseconds, and has a small RAM footprint compared to the Node.js-based Gemini CLI it replaces.

Key capabilities:

• Multi-agent orchestration — the main agent spawns specialized subagents on the fly to handle focused subtasks in parallel
• Multi-model support — exposes eight models in one terminal: Gemini 3.x, Claude Sonnet 4.6, Claude Opus 4.6, and GPT-OSS 120B
• Bidirectional sync — context syncs between the CLI and the Antigravity 2.0 desktop GUI; switch between terminal and GUI without losing session state
• Async parallel work — runs large refactors or multi-topic research in the background without locking the terminal
• YOLO Mode — no-confirmation execution for trusted automated workflows
• New slash commands — /goal and /schedule (no equivalent in Gemini CLI)

The default model is Gemini 3.5 Flash (High), announced at Google I/O 2026. This is important for the benchmark comparison below — Antigravity’s speed numbers come from Flash, not a frontier reasoning model.

Claude Code: What It Is and How It Works

Claude Code is Anthropic’s terminal-based coding agent. The latest build as of June 2026 is v2.1.126. It runs natively on macOS, Linux, and Windows (no npm/Node.js required with the native installer), and supports parallel sessions each with a 1 million token context window.

Key capabilities:

• 1 million token context window — load entire codebases, full documentation, and extended conversation history in one session
• CLAUDE.md project memory — persistent project instructions that Claude reads at the start of every session; equivalent to Gemini CLI’s GEMINI.md
• MCP server integrations — connects to GitHub, databases, Slack, filesystem, and hundreds of custom tools via the Model Context Protocol
• Careful confirmation flow — granular approval prompts before file writes, commands, or external calls; designed for developers who want oversight
• Multi-model access — Haiku 4.5, Sonnet 4.6, Opus 4.7/4.8, and Fable 5 available depending on plan

JetBrains’ 2026 developer survey found Claude Code has a 75% adoption rate at small companies, making it the most widely used AI coding tool in that segment. The developer quote making the rounds: “Claude Code is expensive, reckless, and weirdly fun.”

Benchmarks: Speed vs Quality

The headline numbers tell a clear story about the trade-off between the two tools.

Metric	Antigravity CLI	Claude Code
Token throughput	~289 tok/s (Gemini 3.5 Flash)	~67 tok/s
SWE-Bench Pro (Opus 4.7 / Flash)	55.1%	64.3%
Claude Opus 4.8 SWE-Bench Pro	N/A	69.2%
Claude Fable 5 SWE-Bench Pro	N/A	80.3% (leaderboard top)
Context window	Varies by model (up to 1M on Claude backend)	1 million tokens
Startup time	Milliseconds (Go binary)	Seconds (native installer)

Antigravity CLI is roughly 4x faster in raw token output because its default model, Gemini 3.5 Flash, prioritises speed over depth. Claude Code scores about 9 percentage points higher on SWE-Bench Pro because its default model, Claude Opus 4.7, prioritises code quality and reasoning over raw throughput.

This is not a fair model-to-model comparison. Antigravity supports Claude Sonnet 4.6 and Claude Opus 4.6 as alternative models in the same terminal. If you switch Antigravity to run on Claude Opus 4.6, the quality gap narrows significantly while the speed advantage narrows too. The benchmark numbers above reflect the default experience, not the maximum capability of either tool.

Pricing: Antigravity Has the Better Free Tier

Tier	Antigravity CLI	Claude Code
Free	~20 agent requests/day, no credit card	No free tier
Pro	$20/month	$20/month
Mid tier	$25 for 2,500 AI credits (pay-as-you-go)	Max 5x: $100/month ($100 in credits)
Top tier	Ultra $249.99/month	Max 20x: $200/month ($200 in credits)

Antigravity has a genuine no-credit-card free tier with about 20 agent requests per day, refreshing approximately every 5 hours. Claude Code has no free tier. You need at minimum a Claude Pro subscription at $20/month, and heavy agentic usage will run $100 to $200 per developer per month in practice.

If you are a Gemini CLI free-tier user who was getting meaningful value at no cost, Antigravity is the natural migration path on pricing alone. Claude Code does not have an equivalent entry point.

How to Migrate from Gemini CLI (Step-by-Step)

Migrating to Antigravity CLI (Official Path)

1. Back up your config: gemini config export > gemini_config_backup.json
2. Install Antigravity CLI:
   macOS/Linux: curl -fsSL https://antigravity.google/cli/install.sh | bash
   Windows PowerShell: irm https://antigravity.google/cli/install.ps1 | iex
3. Authenticate: Run agy — it opens a browser for Google OAuth. Use the same Google account as Gemini CLI.
4. Import plugins: agy plugin import gemini — scans your Gemini CLI plugin directory and registers each plugin with agy.
5. Move workspace skills: Move files from .gemini/skills/ to .agents/skills/ manually (Antigravity does not auto-detect the old path).
6. Update scripts and CI: Replace gemini with agy in Makefiles, shell scripts, and CI pipeline configs.
7. Validate: agy doctor

Migrating to Claude Code

1. Install Claude Code:
   macOS/Linux: curl -fsSL https://claude.ai/install.sh | bash
   Windows PowerShell: irm https://claude.ai/install.ps1 | iex
   npm (cross-platform): npm install -g @anthropic-ai/claude-code
2. Subscribe: Claude Code requires at minimum a Claude Pro plan at $20/month or direct Anthropic API access.
3. Authenticate: Run claude — authenticates via browser with your Anthropic account.
4. Create project memory: Add a CLAUDE.md file to your project root. This is the equivalent of Gemini CLI’s GEMINI.md — Claude Code reads it as persistent instructions and context at the start of every session.
5. Reconfigure tool integrations: Claude Code uses MCP servers for tool access. Gemini CLI plugins do not import directly. Each integration needs to be set up manually via claude mcp add.
6. Verify: claude --version, claude doctor, claude update

When to Choose Antigravity CLI

• You were on Gemini CLI’s free tier and need a no-cost replacement immediately
• Speed is the priority — 289 tok/s vs 67 tok/s is a 4x difference that matters in automated pipelines and rapid iteration loops
• You want to stay in Google’s ecosystem — OAuth continues, Workspace integrations carry over, familiar command patterns
• You want multi-model flexibility in one terminal — Antigravity exposes Gemini, Claude, and GPT-OSS models side by side
• You do agentic research or multi-step automation tasks where Flash’s speed and the multi-agent orchestration architecture add real value

When to Choose Claude Code

• Code quality is the non-negotiable — a 9-point SWE-Bench Pro gap (64.3% vs 55.1%) translates into measurably fewer wrong answers on complex multi-file tasks
• You work on large codebases — the 1 million token context window lets you load entire repositories in a single session without chunking
• You want the best agentic coding model available — Claude Fable 5 sits at 80.3% on SWE-Bench Pro, the top of the leaderboard as of June 2026
• You already use Claude for other work — a single Claude Pro subscription covers both API use and Claude Code credits
• You want granular confirmation flows — Claude Code’s approach is more careful and transparent about what it is doing before it does it

What exactly is Antigravity CLI?

Antigravity CLI, binary name agy, is Google’s official replacement for Gemini CLI. It was announced at Google I/O on May 19, 2026, and is the terminal surface of the Antigravity 2.0 platform. It is written in Go, supports multi-agent orchestration and multi-model switching, and is closed source — a significant departure from Gemini CLI’s Apache 2.0 license.

Does Antigravity CLI have a free tier?

Yes. Antigravity CLI offers approximately 20 agent requests per day on the free tier, with no credit card required. The quota refreshes roughly every 5 hours. This makes it the natural replacement for developers who were using Gemini CLI for free.

Is Claude Code better than Antigravity CLI?

On code quality, yes. Claude Code with Opus 4.7 scores 64.3% on SWE-Bench Pro versus Antigravity’s 55.1%. Claude Fable 5 extends that to 80.3%. On raw speed, Antigravity wins decisively at ~289 tok/s versus ~67 tok/s. The right choice depends on whether your workflow needs fast output or accurate output.

Can I use both tools at the same time?

Yes, and some developers already do. There is a community-built MCP bridge called Claude-Code-Antigravity-CLI-MCP-Server on GitHub that lets Claude Code spawn Antigravity as a sub-agent. The combination lets you use Claude Opus for deep reasoning tasks while delegating speed-sensitive subtasks to Antigravity running Gemini Flash.

Wrapping Up

The June 18 deadline is real and it is close. Both tools are genuinely capable, but they serve different defaults: Antigravity prioritises speed and Google ecosystem continuity; Claude Code prioritises code quality and large-context reasoning.

1. If you are on the free tier, migrate to Antigravity CLI today. The install takes under 10 minutes and the free tier is comparable to what you had with Gemini CLI.
2. If code quality drives your choice, start a Claude Pro trial. The $20/month gets you Claude Code with Sonnet 4.6, which outperforms Antigravity’s default model on complex tasks.
3. Consider running both. The community-built MCP bridge already makes this practical. Antigravity for speed, Claude Code for depth — the combination costs $20/month on top of whatever Google tier you already pay.