The plugin targets Google's Antigravity first, with other tools listed as coming later. Google says thousands of its own engineers use it daily to ship production code.
It runs in three steps. egm-brainstorm is a no-code design conversation where the AI interviews you. egm-draft writes a Markdown design doc with the problem, plan, alternatives and the exact files to change. egm-review hands that doc to stateless sessions: one has to explain the plan back (if it can't, the doc is unclear), several play skeptical reviewers looking for edge cases, and a last one does a go/no-go check that every file path, data structure and function signature is spelled out.
The repo ships the Markdown rules, subagent personas and review workflows, so you can copy the pattern even if you don't use Antigravity.