A developer created 'loop', a simple CLI tool, to enable Claude and Codex to act as pair programmers. The tool launches both agents side-by-side in tmux, using a bridge for direct communication. This mimics human collaboration, where one agent acts as the main worker and the other as a reviewer.

The developer found that even when both agents gave the same feedback, it wasn't annoying but a strong signal, leading to a 100% resolution rate on code reviews. loop makes the feedback loop faster and more natural, preserving context across iterations.