The productivity gains of people using their own "custom" harnesses and agent tooling (e.g. letting agents talk to eachother over a messaging board) is questionable at best a waste of time at worst. No one I've talked to is actually applying the scientific method and measuring how long and how many tokens it costs to get a certain task done with just a plain chat input vs all this custom harness/tooling crap.
All you need is the source code for your existing project and the claude code/codex/opencode cli and boom, you are ready to ship. Most people doing the impressive stuff with AI are just using it, not building harnesses or "agentic" tooling.
All you need is the source code for your existing project and the claude code/codex/opencode cli and boom, you are ready to ship. Most people doing the impressive stuff with AI are just using it, not building harnesses or "agentic" tooling.