They were missing a harness like Claude Code or Codex (terminal). However they recently released Grok Build, which is probably the fasted I've used, in terms of responsiveness, but didn't have a model at Opus 4.7/8 level. The thing is if they add 4.5 to Grok Build and keep improving the harness I think it can compete (cheaper and faster).

I've been using Grok Build over the last couple weeks. It's actually a very good CLI. The Grok Build 0.1 model isn't great but can also use Composer 2.5 which is excellent. Well worth trying.