---
name: codex-implementation
description: Ask Codex CLI (gpt-5.5) to implement scoped code changes in the current repository, then have Claude inspect the resulting diff and verification. This is how gpt-5.5 is invoked for implementation work. Use when the user asks Claude to delegate implementation to Codex or gpt-5.5, when the model-selection rubric routes the work to gpt-5.5, or when a bounded task would benefit from another coding agent producing a patch.
---

# Codex Implementation

Use Codex as a separate implementation agent for bounded code changes. Claude remains responsible for scoping the task, reviewing the diff, running or checking verification, and explaining the final result.

Use this when the user asks for Codex or delegation, or when a bounded task would benefit from a parallel implementation agent producing a patch. Do not let Codex commit, push, deploy, or edit global config unless the user explicitly asked for that.

## Workflow

1. Pin the current state with `git status --short` and note any user changes already present.
2. Define the implementation scope: files or behavior to change, files to avoid, constraints, and verification commands.
3. Create a temporary artifact directory for Codex's report.
4. Run `codex exec` with repo write access.
5. After Codex exits, inspect `git status` and `git diff`.
6. Run the cheapest reliable verification yourself when practical.
7. Report what Codex changed, what Claude verified, and any remaining risks.

Use this command shape:

```bash
ARTIFACT_DIR="$(mktemp -d "${TMPDIR:-/tmp}/codex-implementation.XXXXXX")"
REPORT="$ARTIFACT_DIR/report.md"
PROMPT="$ARTIFACT_DIR/prompt.md"

# Write a self-contained prompt to $PROMPT, then run:
codex exec \
  -C "$PWD" \
  # NOTE: the rest of this command (likely -s workspace-write, an -o "$REPORT"
  # output flag, and "$(cat "$PROMPT")") scrolled past before it could be
  # captured on screen in the source video — fill in following the
  # codex-review / codex-computer-use pattern above.
```

## Example Prompt

Report:
- Files changed
- Behavioral summary
- Verification run and result
- Anything blocked or uncertain

## Review After Codex

Always inspect Codex's diff before telling the user the work is done. Revert only Codex-created mistakes when you are sure they are not user changes. If Codex leaves the repo in a worse state than requested, revert unrelated files and report the issue with a diff summary.

If `codex` is not installed or the command fails, report the error and offer to implement the change directly instead.