Implement Spec with Codex

Run implement-spec exactly, same loop, same gates, same maintenance checkpoints, but Codex writes the code. Invoking this skill IS the explicit ask that authorizes codex exec delegation under the codex skill.

Role split

• Codex implements, whenever possible. Default every implementation pass to a codex exec, sliced sharp and prompted per the codex skill (prompt blocks, sandbox choice, exec liveness). Run independent slices as concurrent execs in separate worktrees, exactly where implement-spec would fan out subagents.
• You orchestrate and review. The spec loop stays yours: pick the next slice, reconcile plan with code, author each prompt end-to-end, integrate diffs, run the gates, review the merged tree, commit, update the handoff, run maintenance checkpoints. None of that delegates.

Keep a pass yourself only when slicing it sharply would cost more than doing it, tiny fixups, plan reconciliation, integration conflicts.

Rules

• You own every result: read the full diff and run the verification yourself. "Codex says it's done" is never done.
• Visual results carry implement-spec's two extra proofs (production-route pixel diff + unprimed critique) with double force here: a sandboxed Codex never saw its change render, so a pass that misses the production render path entirely arrives looking fully "verified".
• A sandboxed Codex ships code it never saw run, browser-verify every visual slice yourself and budget fix rounds. Send a red gate back as a resumed follow-up with the failing evidence; fix it yourself only when that's smaller than re-prompting.
• Commit hygiene stays yours: review the change list of the merged tree before every commit, exactly as implement-spec demands of the integrating reviewer.