What's the best harness to use with it?

I've enjoyed using https://omp.sh/

Seconded. I love OpenCode and Pi, but omp is my daily driver.

What's good about it? I use OpenCode and it does what I need, basically.

Spawning subagents via orchestrate and using /advisor are both super valuable. Haven't really unlocked the full capability of omp yet, but hoping to over time.

omp - current top, after using codex claude opencode pi that I still use too