Execute Spec in Fork

Turn one approved SPEC READY into a disposable Codex execution task. Keep product decisions in the planning task, keep implementation logs in the fork, and return evidence to the planning task automatically.

Require a launchable contract

Before creating anything:

1. Find the latest completed SPEC READY block and apply later user corrections.
2. Require it to route to forked execution, fit one reliable implementation session, and contain no unresolved product decisions. Use /to-tickets or /to-goal when it does not.
3. Require the current harness to expose native Codex App task tools for forking, messaging, reading, naming, pinning, and archiving.
4. Require /codex-task-messenger to be installed with its Ask, Reply, and Resume card protocol (v2 or later) available.

If a prerequisite is missing, do not create a plain new task or simulate the transport. Explain the missing capability and give the manual fallback: fork from the final SPEC READY, run /spec-executor there, and paste its receipt back. After the receipt is pasted, ask once for Goal / spec quality; a skipped answer does not block using the receipt.

Harness capability map

This workflow is a Codex App adapter, so it depends on that harness's task tools by name. The names live here and nowhere else; everything below this section is written in capabilities. When a tool is renamed or reshaped, change this table only. The decision and its consequences live in ADR 0003.