> Very fast efficient UI driven (multi app/web/desktop at the same time, agnostic) validation while you vibe.

This sounds neat in practice, but what does this mean exactly?

Most devs I know integrate Opencode/Codex/etc through something like Playwright-MCP which handles testing, physically clicking on elements, and validation through a combination of DOM inspection, JS evals, and screenshots.

It's not the fastest thing in the world because it still has to spin up a browser (headless or otherwise) - but I don't see how that's avoidable if you want genuine E2E testing.