Antigravity CLI vs Claude Code vs Codex CLI: Which Terminal Agent After Gemini CLI?

TL;DR

Google killed Gemini CLI for individual users. Starting June 18, 2026, the open-source tool that hit 100K GitHub stars stops serving requests unless you’re on an enterprise license. Its replacement, Antigravity CLI, is closed-source, built in Go, and ships with aggressive rate limits that lock free-tier users out for up to seven days after 20-30 minutes of use. I’ve been running all three terminal agents (Antigravity CLI, Claude Code, and Codex CLI) side by side for the past week. Claude Code still wins on code quality and deep reasoning. Codex CLI wins on token efficiency and open-source trust. Antigravity CLI has the multi-agent orchestration story but its rate limits make it hard to recommend on any plan below Ultra.

Google’s Forced Migration

Google announced Antigravity CLI at I/O 2026 on May 19. Two days later, the Gemini CLI deprecation notice went live. The timeline is tight:

• May 19: Antigravity CLI launches, available to everyone
• June 18: Gemini CLI stops serving requests for Google AI Pro, Ultra, and free-tier users
• June 18+: Gemini Code Assist for GitHub stops accepting new installations

Enterprise customers with Gemini Code Assist Standard or Enterprise licenses keep their Gemini CLI access indefinitely. Everyone else migrates or switches tools.

The backlash was immediate, and for good reason. Gemini CLI was open source under Apache 2.0. Antigravity CLI isn’t. The GitHub repository contains a changelog, a readme, and a demo GIF, but no actual source code. The rate limits on the replacement are drastically more restrictive than what Gemini CLI users had. And the 30-day migration window is enough time to install a binary, but it’s nowhere near enough to rebuild CI pipelines, port custom extensions, or audit a closed-source tool’s data handling.

I ran Gemini CLI daily for the tutorial I wrote in May. It worked well for what it was: a Node.js-based terminal agent with Gemini models, MCP support, and a sensible free tier. Antigravity CLI is supposed to be the upgrade. In practice, the experience is more complicated.

Antigravity CLI: What You Actually Get

Installation is straightforward:

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

# Verify
agy --version

The binary is agy, not antigravity. Authentication uses browser-based Google Sign-In. It opens your default browser, you log in, and the token stores in your system keyring. On SSH sessions, it prints a URL you complete in a local browser.

Antigravity CLI shares its backend with the Antigravity 2.0 desktop app. Conversations started in the CLI can be exported to the desktop GUI. Skills, hooks, MCP servers, and context files (GEMINI.md, AGENTS.md) all carry over from Gemini CLI, though the config paths change:

# MCP config (global)
~/.gemini/antigravity/mcp_config.json

# MCP config (workspace)
.agents/mcp_config.json

# Skills (global)
~/.gemini/antigravity/skills/

# Migrate existing Gemini CLI extensions
agy plugin import gemini

The Go rewrite does feel faster. Startup time dropped from ~1.2s (Gemini CLI on Node.js) to around 300ms. Memory overhead is lower. The TUI is keyboard-optimized and responsive. On pure ergonomics, it’s an improvement.

Where things fall apart is the rate limiting.

The Rate Limit Problem

Antigravity CLI uses a metric Google calls “compute effort” instead of transparent token counts. A simple question might consume 1 unit. A multi-file refactoring task might eat 50. The UI shows a capacity percentage, but it’s unreliable. One XDA reviewer reported their meter showed “100% capacity remaining” right before a 7-day lockout triggered.

The tiers:

For comparison, Claude Code’s Max 5x plan ($100/mo) gives you a consistent 5x the Pro window every 5 hours with no weekly ceiling. Codex CLI’s Pro plan ($200/mo) gives 20x Plus limits. Neither tool has users reporting multi-day lockouts on paid tiers.

I hit the free-tier wall on my second day with Antigravity CLI. A refactoring session across four files, maybe 25 minutes of active prompting, triggered a full weekly lockout. The Pro tier lasted longer but I still bumped into cooldowns during a two-hour coding session. The quota system feels tuned for casual one-off questions and breaks down fast during real development sessions.

Head-to-Head Comparison

Architecture, Models, and Benchmarks

The open-source gap is significant. Codex CLI’s full codebase lives on GitHub under Apache 2.0. Claude Code isn’t open source either, but Anthropic publishes transparent token pricing, so you can predict costs. Antigravity CLI is closed-source with opaque “compute effort” billing. You can’t inspect what the tool sends to Google’s servers, and you can’t predict what a task will cost before you run it.

On SWE-bench, the 72% vs 80-81% split comes down to the models: Gemini 3.1 Pro trails Opus 4.7 and GPT-5.4 on complex code generation. I broke down those model-level differences in GPT-5.4 vs Claude Opus 4.7 vs Gemini 3.1 Pro for coding. If Google ships Gemini 3.5 Pro support (currently only Flash is available for free-tier users), that gap could narrow.

Token efficiency is impossible to compare directly because Antigravity CLI doesn’t expose token counts. I compared Claude Code and Codex CLI’s real-world token usage before. Codex uses roughly 4x fewer tokens for the same task. Antigravity CLI’s “compute effort” metric makes the same comparison impossible.

Pricing

At the $20/mo entry point, all three tools are nominally equivalent. In practice, Claude Code’s Pro plan gives a predictable 5-hour window that resets cleanly. Codex CLI’s Plus plan similarly refreshes without drama. Antigravity CLI’s Pro tier refreshes every 5 hours but sits under a weekly ceiling that’s caused lockouts for multiple users.

At the $100/mo tier, Claude Code’s Max 5x is the most predictable option: 5x the Pro quota per window, no weekly cap, no multi-day cooldowns. Codex CLI’s promotional Pro pricing through May 31 gives 10x usage (normally 5x). Antigravity CLI’s Ultra entry offers 5x Pro limits but users still report occasional throttling.

If you’re paying $200+, all three tools give you generous quotas. But at that price point, predictability and transparancy become the differentiators. Claude Code and Codex CLI both show you exactly what you’re consuming. Antigravity CLI does not.

Multi-Agent Capabilities

Antigravity CLI’s strongest differentiator is the Agent Manager. The Agent Manager lets you run multiple agents simultaneously in a dashboard-style view. You can kick off a refactoring agent, a test-writing agent, and a documentation agent in parallel. Progress is visible in a unified TUI. Conversations can be handed off between CLI and the Antigravity 2.0 desktop app.

Claude Code has subagents too. I covered the practical setup in a separate guide. They run in parallel via the Agent tool. But Claude Code’s subagent model is programmatic: you manage orchestration through prompts and return values, with no dashboard view. You spawn agents with prompts, they return results, and you manage the orchestration in your conversation. There’s no dashboard.

Codex CLI runs parallel tasks in sandboxed environments. Each task gets its own filesystem context. It’s effective for batch operations but lacks the visual orchestration layer.

If your workflow involves multiple concurrent agents, say running a migration on three services simultaneously, Antigravity CLI’s Agent Manager is the most polished interface for that. But most daily coding work is sequential: read, think, write, test. The multi-agent advantage is real but narrow.

What I’d Actually Pick

After running all three for a week, my recommendations split along three axes:

Pick Claude Code if you care about code quality above everything else. Opus 4.7 produces the cleanest, most idiomatic code of the three. The 81% SWE-bench score translates to noticeably fewer first-pass errors. Pricing is transparent and the Max plans give predictable capacity. The trade-off is higher token consumption. Claude Code thinks out loud and burns tokens doing it. If you’re on the API, Sonnet 4.6 at $3/$15 per million tokens handles 90% of daily work.

Pick Codex CLI if you prioritize token efficiency, open-source transparency, or autonomous batch work. It uses 4x fewer tokens than Claude Code for the same tasks, and its 77.3% Terminal-Bench score shows it’s strongest at shell-oriented work. The Apache 2.0 license means you can inspect every line of code your agent runs. The promotional Pro pricing ($100/mo for 10x usage through May 31) is the best value in this comparison right now.

Pick Antigravity CLI if you’re already deep in Google’s stack (GCP, Gemini API, Antigravity 2.0 desktop) and the multi-agent orchestration fits your workflow. The Go rewrite is fast and the Agent Manager UI is well-designed. But go in with your eyes open about the rate limits. Below the Ultra tier, the lockouts are unpredictable enough that I wouldn’t rely on it as my primary tool for deadline-sensitive work.

Skip Antigravity CLI if you’re a current Gemini CLI user who valued the open-source codebase, transparent usage metrics, and generous free tier. The replacement is a downgrade on all three of those dimensions. Google knows this. Enterprise customers get to keep Gemini CLI indefinitely. Individual developers don’t get that option.

Migration Guide for Gemini CLI Users

If you’re currently on Gemini CLI and need to decide before June 18, here’s the practical checklist:

Staying on Google’s stack (Antigravity CLI):

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

# Import your Gemini CLI extensions
agy plugin import gemini

# Move MCP configs
cp ~/.gemini/settings.json ~/.gemini/antigravity/mcp_config.json
# (manual edit needed — serverUrl replaces url for remote servers)

# Move skills
cp -r ~/.gemini/skills/ ~/.gemini/antigravity/skills/

# Context files (GEMINI.md) work unchanged

Switching to Claude Code:

# Install
npm install -g @anthropic-ai/claude-code

# Create context file
# Rename your GEMINI.md to CLAUDE.md (same concept, different name)
mv GEMINI.md CLAUDE.md

# MCP config goes in .claude/settings.json

Switching to Codex CLI:

# Install
npm install -g @openai/codex

# Context file is AGENTS.md (same name Antigravity uses)
# MCP config via codex config

All three tools support MCP servers, so any MCP integrations you’ve built will carry over with minimal config changes. The main migration cost is rewriting context files and adjusting to each tool’s quirks.

FAQ

Is Antigravity CLI open source?

No. The GitHub repository contains documentation and a demo GIF, but no source code. This is a significant departure from Gemini CLI, which was fully open source under Apache 2.0. Codex CLI is the only remaining open-source option among the three major terminal agents.

Will Gemini CLI keep working after June 18?

Only for enterprise users with Gemini Code Assist Standard or Enterprise licenses, or those using paid Gemini Enterprise Agent Platform API keys. Individual Pro, Ultra, and free-tier users lose access on June 18, 2026.

Can I use Antigravity CLI for free?

Technically yes, but the free tier is limited to roughly 20 agent requests per day, and users report weekly lockouts lasting up to 7 days after moderate usage. For anything beyond occasional one-off questions, you’ll need a paid plan.

How do Antigravity CLI rate limits compare to Claude Code and Codex CLI?

Claude Code’s paid plans (Pro $20/mo, Max $100-200/mo) use transparent token-based quotas that refresh every 5 hours with no weekly cap. Codex CLI’s Plus ($20/mo) and Pro ($200/mo) similarly refresh without multi-day lockouts. Antigravity CLI’s paid plans refresh every 5 hours but sit under a weekly ceiling that has caused 6-10 day cooldowns for Pro tier users.

Which terminal agent has the best code quality?

Claude Code, powered by Opus 4.7, scores highest on SWE-bench Verified (~81%) and wins 67% of blind code quality evaluations. Codex CLI with GPT-5.4 is close at ~80% on SWE-bench but scores lower on blind quality tests. Antigravity CLI with Gemini 3.1 Pro sits at ~72%.

Sources

• Transitioning Gemini CLI to Antigravity CLI — Google Developers Blog — official deprecation and migration announcement
• Choosing Antigravity or Gemini CLI — Google Cloud Blog — Google’s own feature comparison
• Antigravity CLI Deep Dive — Agentpedia — technical details on installation, config, and architecture
• Google Antigravity limitation — XDA Developers — hands-on review documenting rate limit issues
• Bye-bye, Gemini CLI — The Register — community backlash and open-source concerns
• Claude API Pricing — Anthropic — current Claude model pricing

Bottom Line

Google had something good with Gemini CLI: an open-source terminal agent with reasonable limits and a growing community. Antigravity CLI is technically better (Go is faster than Node.js, the multi-agent orchestration is real) but worse in every dimension that built trust: it’s closed-source, the rate limits are punishing, and the migration timeline is aggressive.

If you’re a Gemini CLI user deciding right now, the honest recommendation is: try Antigravity CLI for a day and see if the rate limits work for your usage pattern. If they don’t, Claude Code at $100/mo (Max 5x) gives you the best code quality with predictable capacity. Codex CLI at $20/mo gives you the best token efficiency with full source-code transparency. Both tools have been stable for months while Antigravity CLI is still in its first week.

I’ve switched back to Claude Code as my daily driver. The rate limit story has to change before I’d trust Antigravity CLI on a deadline.