Comment by philipp-gayret

> - A SKILL.md system mirroring Anthropic's skills convention.

> - Subagents, an artifacts review workflow (slash commands), and conversation rewind.

Antigravity CLI, like Gemini CLI, is a copy of most of Claude Code. At least in Antigravity CLI they copied the better UI as well. The scope of copying includes support for definitions of Agents, Skills, Commands, Plugins, MCP and so on. In fact, for some time, the Gemini CLI "extensions" documentation referred directly to Claude Code marketplace repositories. An artifact of this is that for example CLAUDE_PROJECT_DIR is made available to hooks, by Gemini CLI.