Gemini CLI was open source (Apache 2): https://github.com/google-gemini/gemini-cli
Antigravity CLI is not - the repo has a README and an animated gif demo: https://github.com/google-antigravity/antigravity-cli
There's a comment from a Googler that there's a chance Antigravity will be open sourced.
There's a comment from a Googler that there's a chance Antigravity will be open sourced.