Codex reviews Claude Code script: 4 issues, then 1, then 0

The engineer's own write-up is notable for showing how the two tools were kept from sharing context: Claude Code and Codex do not share conversations, so the handoff note at docs/handoff.md carries only three items — current state, what changed, and the next request. The note limited the reviewer's scope to uncommitted changes and told it not to fix anything, leaving the decision on which points to accept with the author and Claude Code. Codex did not just return opinions; it wrote small tests to reproduce each point before reporting, without touching the file.

Across the three rounds the reviewers' notes never appeared in the author's own check, which had covered only two prepared sample cases. That said, the engineer is explicit that this is a single small script and cannot be generalized. The test of whether the approach is worth copying is whether review catches what the author did not try, and whether the author can keep the reviewer read-only.