Antigravity CLI is a terminal agent Google announced at I/O on May 19, 2026. Written in Go (versus Gemini CLI's Node.js), its binary is called agy, and it shares the same agent harness as the desktop Antigravity 2.0. It is also Gemini CLI's successor — the personal-tier Gemini CLI service ends on June 18, 2026.
AI models rationalize their own code when reviewing it. Using three different CLIs for independent review effectively catches blind spots -- this post covers the design philosophy and practical workflow patterns behind the approach.
Agent Skills is Addy Osmani's open-source collection of 19 production-grade engineering skills that drive AI agents to follow senior engineering discipline through /spec → /plan → /build → /test → /review → /ship commands, instead of cutting corners.
The paying paths on Google's side: the individual free tier and Gemini CLI access on Google AI Pro / Ultra ended 2026/6/18, leaving individuals with Antigravity CLI or their own paid API key; enterprise licenses and Google Cloud are unaffected. The zero-cost starting option now belongs to someone else.
A comparison of six agent CLI subscriptions (Claude Code, Cursor CLI, Codex, Kiro, Antigravity/Gemini CLI, OpenCode) plus the multi-model routing pattern — cheap models for simple work, strong models for hard work. Nearly every one of these changed its billing in the first half of 2026; this version was re-verified on 8/18.
Agent CLIs are not smarter autocomplete tools -- they are AI agents that can read your codebase, execute multi-step tasks, and operate in real environments. Claude Code, Codex CLI, Gemini CLI, OpenCode, Aider, Pi, Kiro, Amp, Cursor CLI... the tools keep multiplying, but they all share a common set of design principles -- understanding these principles is how you actually get good at using them.