Yes, like many others I've been experimenting a lot. What I've got so far is a harness-of-harnesses - ie, a harness which sits on top of Claude Code, Codex or OpenCode. I still use Claude Code or Codex directly for the initial planning of features, to investigate issues, and for small fixes, but whenever there's something even just a bit complex to do, I use my second-level harness.

Summarizing it a lot, what it does is:

* help you make better plans

* split plans into iterations, in a module-aware way for projects which have strict modularity (for now I'm doing this specifically with TypeScript and dependency cruiser) - this helps a lot when a project becomes complex

* ask an agent to implement an iteration, and then programmatically run a lot of checks after each iteration - not just regression tests, but also checks against project principles and conventions

* when possible, automatically fix deviations; when not possible, raise them to myself for an end-of-plan review

In this way, instead of having to constantly be engaged with the chat interface, with all the shorter or longer wait times which break my flow, I spend a lot of highly focused time during initial planning and final review. A plan implementation can go on for hours, and the various anchoring mechanisms added to the tool keep drift to a minimum.

At some point I'm planning to release this tool as open source. As this is the result of months of trial and errors, dogfooding, and vibecoding on the tool itself, the codebase is chaotic and the UI is still full of experiments I mostly basically abandoned, and I'm not used to releasing stuff in this status. But perhaps, in this brave new world, I should just do it and see what happens?