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.
Gemini CLI will be discontinued on 2026/06/18, with Antigravity CLI as the official successor. Before shutdown: free 60 req/min, 1,000 req/day, including Gemini 2.5 Pro and 1M token context window. Skills, Hooks, and Subagents can all be migrated.
Comparing six major Agent CLI subscription plans in 2026 (Claude Code, Cursor CLI, Codex, Kiro, Gemini CLI, OpenCode), and exploring multi-model routing patterns — routing simple tasks to cheaper models and complex tasks to flagship models, with real-world savings of 40-85%.
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.