ai-coding-skills/skills/implement-plan/codex/SKILL.md

---
name: implement-plan
description: Use when a plan folder (from create-plan) exists and needs to be executed in an isolated git worktree with iterative cross-model milestone review. ALWAYS invoke when user says "implement the plan", "execute the plan", "start implementation", "resume the plan", or similar execution requests.
---

# Implement Plan (Codex Native Superpowers)

Execute an existing plan (created by `create-plan`) in an isolated git worktree, with iterative cross-model review at each milestone boundary.

## Overview

This skill wraps the Superpowers execution flow for Codex:
1. Locate plan files under `ai_plan/`
2. Set up an isolated git worktree
3. Execute milestones one-by-one with lint/typecheck/test gates
4. Review each milestone with a second model/provider
5. Commit approved milestones, merge to parent branch, and delete worktree

**Core principle:** Codex uses native skill discovery from `~/.agents/skills/`. Do not use deprecated `superpowers-codex bootstrap` or `use-skill` CLI commands.

## Prerequisite Check (MANDATORY)

Required:
- Plan folder exists under `ai_plan/` at project root
- `continuation-runbook.md` exists in plan folder
- `milestone-plan.md` exists in plan folder
- `story-tracker.md` exists in plan folder
- Git repo with worktree support: `git worktree list`
- Superpowers skills symlink: `~/.agents/skills/superpowers -> ~/.codex/superpowers/skills`
- Superpowers execution skills:
  - `superpowers:executing-plans`
  - `superpowers:using-git-worktrees`
  - `superpowers:verification-before-completion`
  - `superpowers:finishing-a-development-branch`

Verify before proceeding:

```bash
test -L ~/.agents/skills/superpowers
test -f ~/.agents/skills/superpowers/executing-plans/SKILL.md
test -f ~/.agents/skills/superpowers/using-git-worktrees/SKILL.md
test -f ~/.agents/skills/superpowers/verification-before-completion/SKILL.md
test -f ~/.agents/skills/superpowers/finishing-a-development-branch/SKILL.md
```

If any dependency is missing, stop and return:

`Missing dependency: [specific missing item]. Ensure all prerequisites are met, then retry.`

If no plan folder exists:

`No plan found under ai_plan/. Run create-plan first.`

## Required Skill Invocation Rules

- Invoke relevant skills through native discovery (no CLI wrapper).
- Announce skill usage explicitly:
  - `I've read the [Skill Name] skill and I'm using it to [purpose].`
- For skills with checklists, track checklist items with `update_plan` todos.
- Tool mapping for Codex:
  - `TodoWrite` -> `update_plan`
  - `Task` subagents -> unavailable in Codex; do the work directly and state the limitation
  - `Skill` -> use native skill discovery from `~/.agents/skills/`

## Process

### Phase 1: Locate Plan

1. Scan `ai_plan/` for plan directories (most recent first by date prefix).
2. If multiple plans exist, ask user which one to implement.
3. If no plan exists, stop: "No plan found. Run create-plan first."
4. Read `continuation-runbook.md` first (source of truth).
5. Read `story-tracker.md` to detect resume state (`in-dev` or `completed` stories).
6. Read `milestone-plan.md` for implementation details.

### Phase 2: Configure Reviewer

If the user has already specified a reviewer CLI and model (e.g., "implement the plan, review with claude sonnet"), use those values. Otherwise, ask:

1. **Which CLI should review each milestone?**
   - `codex` — OpenAI Codex CLI (`codex exec`)
   - `claude` — Claude Code CLI (`claude -p`)
   - `cursor` — Cursor Agent CLI (`cursor-agent -p`)
   - `skip` — No external review, proceed with user approval only

2. **Which model?** (only if a CLI was chosen)
   - For `codex`: default `o4-mini`, alternatives: `gpt-5.3-codex`, `o3`
   - For `claude`: default `sonnet`, alternatives: `opus`, `haiku`
   - For `cursor`: **run `cursor-agent models` first** to see available models
   - Accept any model string the user provides

3. **Max review rounds per milestone?** (default: 10)
   - If the user does not provide a value, set `MAX_ROUNDS=10`.

Store `REVIEWER_CLI`, `REVIEWER_MODEL`, and `MAX_ROUNDS`. These values are fixed for the entire run.

### Phase 3: Set Up Worktree (REQUIRED SUB-SKILL)

Invoke `superpowers:using-git-worktrees`.

1. Branch naming: `implement/<plan-folder-name>` (e.g., `implement/2026-03-04-auth-system`).
2. Follow worktree skill's directory priority: `.worktrees/` > `worktrees/` > CLAUDE.md > ask user.
3. Verify `.gitignore` covers worktree directory.
4. Run project setup (auto-detect: `npm install`, `cargo build`, `pip install`, etc.).
5. Verify clean baseline (run tests).

**Resume detection:** If `story-tracker.md` shows `in-dev` or `completed` stories, check if worktree branch already exists (`git worktree list`). If so, `cd` into existing worktree instead of creating a new one.

### Phase 4: Execute Milestones (Loop)

For each milestone (M1, M2, ...):

#### Step 1: Read Milestone Spec

Read the milestone section from `milestone-plan.md`.

#### Step 2: Update Tracker

Mark first story `in-dev` in `story-tracker.md`.

#### Step 3: Implement Stories

Execute each story in order. After completing each story:
1. Mark `in-dev` -> `completed` in `story-tracker.md`
2. Update counts
3. Mark next story `in-dev`

Commit hashes are not available yet — they are backfilled in Step 6 after the milestone is approved and committed.

#### Step 4: Verify Milestone (REQUIRED SUB-SKILL)

Invoke `superpowers:verification-before-completion`.

```bash
# Lint changed files
# Typecheck
# Run tests (targeted first, then full suite)
```

All must pass before proceeding. If failures: fix, re-verify. Do NOT proceed to review with failures.

#### Step 5: Milestone Review Loop

Send to reviewer for approval **before committing**. See Phase 5 for details. The review payload uses working-tree diffs (`git diff` for unstaged, `git diff --staged` for staged changes).

**Skip this step if reviewer was set to `skip`.** When skipped, present the milestone summary to the user and ask for approval directly.

#### Step 6: Commit & Approve

Only after the reviewer approves (or user overrides at max rounds):

```bash
git add <changed-files>
git commit -m "feat(<scope>): implement milestone M<N> - <description>"
```

Do NOT push. After committing:
1. Backfill the commit hash into the Notes column for all stories in this milestone in `story-tracker.md`.
2. Mark milestone as `approved` in `story-tracker.md`.
3. Move to next milestone.

### Phase 5: Milestone Review Loop (Detail)

**Skip this phase entirely if reviewer was set to `skip`.**

#### Step 1: Generate Session ID

```bash
REVIEW_ID=$(uuidgen | tr '[:upper:]' '[:lower:]' | head -c 8)
```

Use for all temp file paths: `/tmp/milestone-${REVIEW_ID}.md` and `/tmp/milestone-review-${REVIEW_ID}.md`.

#### Step 2: Write Review Payload

Write to `/tmp/milestone-${REVIEW_ID}.md`:

```markdown
# Milestone M<N> Review: <title>

## Milestone Spec (from plan)
[Copy milestone section from milestone-plan.md]

## Acceptance Criteria
[Copy acceptance criteria checkboxes]

## Changes Made (git diff)
[Output of: git diff -- for unstaged changes, or git diff --staged for staged changes]

## Verification Output
### Lint
[lint output]
### Typecheck
[typecheck output]
### Tests
[test output with pass/fail counts]
```

#### Step 3: Submit to Reviewer (Round 1)

**If `REVIEWER_CLI` is `codex`:**

```bash
codex exec \
  -m ${REVIEWER_MODEL} \
  -s read-only \
  -o /tmp/milestone-review-${REVIEW_ID}.md \
  "Review this milestone implementation. The spec, acceptance criteria, git diff, and verification output are in /tmp/milestone-${REVIEW_ID}.md.

Evaluate:
1. Correctness — Does the implementation match the milestone spec?
2. Acceptance criteria — Are all criteria met?
3. Code quality — Clean, maintainable, no obvious issues?
4. Test coverage — Are changes adequately tested?
5. Security — Any security concerns introduced?

Be specific and actionable. If solid, end with exactly: VERDICT: APPROVED
If changes are needed, end with exactly: VERDICT: REVISE"
```

Capture the Codex session ID from output (line `session id: <uuid>`). Store as `CODEX_SESSION_ID`.

**If `REVIEWER_CLI` is `claude`:**

```bash
claude -p \
  "Read the file /tmp/milestone-${REVIEW_ID}.md and review this milestone implementation.

Evaluate:
1. Correctness — Does the implementation match the milestone spec?
2. Acceptance criteria — Are all criteria met?
3. Code quality — Clean, maintainable, no obvious issues?
4. Test coverage — Are changes adequately tested?
5. Security — Any security concerns introduced?

Be specific and actionable. If solid, end with exactly: VERDICT: APPROVED
If changes are needed, end with exactly: VERDICT: REVISE" \
  --model ${REVIEWER_MODEL} \
  --allowedTools Read \
  > /tmp/milestone-review-${REVIEW_ID}.md
```

**If `REVIEWER_CLI` is `cursor`:**

```bash
cursor-agent -p \
  --mode=ask \
  --model ${REVIEWER_MODEL} \
  --trust \
  --output-format json \
  "Read the file /tmp/milestone-${REVIEW_ID}.md and review this milestone implementation.

Evaluate:
1. Correctness — Does the implementation match the milestone spec?
2. Acceptance criteria — Are all criteria met?
3. Code quality — Clean, maintainable, no obvious issues?
4. Test coverage — Are changes adequately tested?
5. Security — Any security concerns introduced?

Be specific and actionable. If solid, end with exactly: VERDICT: APPROVED
If changes are needed, end with exactly: VERDICT: REVISE" \
  > /tmp/milestone-review-${REVIEW_ID}.json
```

Extract session ID and review text (requires `jq`):

```bash
CURSOR_SESSION_ID=$(jq -r '.session_id' /tmp/milestone-review-${REVIEW_ID}.json)
jq -r '.result' /tmp/milestone-review-${REVIEW_ID}.json > /tmp/milestone-review-${REVIEW_ID}.md
```

If `jq` is not installed, inform the user: `brew install jq` (macOS) or equivalent.

#### Step 4: Read Review & Check Verdict

1. Read `/tmp/milestone-review-${REVIEW_ID}.md`
2. Present review to the user:

```
## Milestone Review — Round N (reviewer: ${REVIEWER_CLI} / ${REVIEWER_MODEL})

[Reviewer feedback]
```

3. Check verdict:
   - **VERDICT: APPROVED** -> proceed to Phase 4 Step 6 (commit & approve)
   - **VERDICT: REVISE** -> go to Step 5
   - No clear verdict but positive / no actionable items -> treat as approved
   - Max rounds (`MAX_ROUNDS`) reached -> present to user for manual decision (proceed or stop)

#### Step 5: Address Feedback & Re-verify

1. Address each issue the reviewer raised (do NOT commit yet).
2. Re-run verification (lint/typecheck/tests) — all must pass.
3. Update `/tmp/milestone-${REVIEW_ID}.md` with new diff and verification output.

Summarize revisions for the user:

```
### Revisions (Round N)
- [Change and reason, one bullet per issue addressed]
```

If a revision contradicts the user's explicit requirements, skip it and note it for the user.

#### Step 6: Re-submit to Reviewer (Rounds 2-N)

**If `REVIEWER_CLI` is `codex`:**

Resume the existing session:

```bash
codex exec resume ${CODEX_SESSION_ID} \
  -o /tmp/milestone-review-${REVIEW_ID}.md \
  "I've addressed your feedback. Updated diff and verification output are in /tmp/milestone-${REVIEW_ID}.md.

Changes made:
[List specific changes]

Re-review. If solid, end with: VERDICT: APPROVED
If more changes needed, end with: VERDICT: REVISE"
```

If resume fails (session expired), fall back to fresh `codex exec` with context about prior rounds.

**If `REVIEWER_CLI` is `claude`:**

Fresh call with accumulated context (Claude CLI has no session resume):

```bash
claude -p \
  "You previously reviewed milestone M<N> and requested revisions.

Previous feedback summary: [key points from last review]

I've addressed your feedback. Updated diff and verification output are in /tmp/milestone-${REVIEW_ID}.md.

Changes made:
[List specific changes]

Re-review. If solid, end with: VERDICT: APPROVED
If more changes needed, end with: VERDICT: REVISE" \
  --model ${REVIEWER_MODEL} \
  --allowedTools Read \
  > /tmp/milestone-review-${REVIEW_ID}.md
```

**If `REVIEWER_CLI` is `cursor`:**

Resume the existing session:

```bash
cursor-agent --resume ${CURSOR_SESSION_ID} -p \
  --mode=ask \
  --model ${REVIEWER_MODEL} \
  --trust \
  --output-format json \
  "I've addressed your feedback. Updated diff and verification output are in /tmp/milestone-${REVIEW_ID}.md.

Changes made:
[List specific changes]

Re-review. If solid, end with: VERDICT: APPROVED
If more changes needed, end with: VERDICT: REVISE" \
  > /tmp/milestone-review-${REVIEW_ID}.json

jq -r '.result' /tmp/milestone-review-${REVIEW_ID}.json > /tmp/milestone-review-${REVIEW_ID}.md
```

If resume fails, fall back to fresh `cursor-agent -p` with context about prior rounds.

Return to Step 4.

#### Step 7: Cleanup Per Milestone

```bash
rm -f /tmp/milestone-${REVIEW_ID}.md /tmp/milestone-review-${REVIEW_ID}.md /tmp/milestone-review-${REVIEW_ID}.json
```

### Phase 6: Completion (REQUIRED SUB-SKILL)

After all milestones are approved and committed:

1. Invoke `superpowers:finishing-a-development-branch`.
2. Run full test suite one final time — all must pass.
3. Merge the worktree branch into the parent branch:

```bash
# From the main repo (not the worktree)
git merge implement/<plan-folder-name>
```

4. Delete the worktree and its branch:

```bash
git worktree remove <worktree-path>
git branch -d implement/<plan-folder-name>
```

5. Mark plan status as `completed` in `story-tracker.md`.

### Phase 7: Final Report

Present summary:

```
## Implementation Complete

**Plan:** <plan-folder-name>
**Milestones:** <N> completed, <N> approved
**Review rounds:** <total across all milestones>
**Branch:** implement/<plan-folder-name> (merged and deleted)
```

## Quick Reference

| Phase | Action | Required Output |
|---|---|---|
| 1 | Locate plan in `ai_plan/` | Plan folder identified, files read |
| 2 | Configure reviewer CLI and model | `REVIEWER_CLI`, `REVIEWER_MODEL`, `MAX_ROUNDS` |
| 3 | Invoke `superpowers:using-git-worktrees` | Worktree created, baseline passing |
| 4 | Execute milestones (loop) | Stories tracked, verified, committed, reviewed |
| 5 | Milestone review loop (per milestone) | Reviewer approval or max rounds + user override |
| 6 | Invoke `superpowers:finishing-a-development-branch` | Branch merged to parent, worktree deleted |
| 7 | Final report | Summary presented |

## Tracker Discipline (MANDATORY)

**ALWAYS update `story-tracker.md` before/after each story. NEVER proceed with stale tracker state.**

Before starting any story:
1. Open `story-tracker.md`
2. Mark story `in-dev`
3. Add notes if relevant
4. Then begin implementation

After completing any story:
1. Mark story `completed`
2. Review pending stories
3. Update Last Updated and Stories Complete counts

Note: Commit hashes are backfilled into story Notes after the milestone commit (Step 6), not per-story.

## Common Mistakes

- Using deprecated commands like `superpowers-codex bootstrap` or `superpowers-codex use-skill`.
- Proceeding to milestone review with failing tests.
- Pushing commits before milestone approval.
- Skipping worktree setup and working directly on the main branch.
- Not capturing the Codex session ID for resume in subsequent review rounds.
- Forgetting to update `story-tracker.md` between stories.
- Creating a new worktree when one already exists for a resumed plan.

## Rationalizations and Counters

| Rationalization | Counter |
|---|---|
| "Bootstrap CLI is faster" | Deprecated for Codex; native discovery is the supported path. |
| "I can skip the worktree for small plans" | Worktree isolation is mandatory — it protects the main branch. |
| "Tests passed earlier, I can skip re-verification" | Each milestone must be independently verified before review. |
| "The reviewer approved, I can skip my own validation" | Reviewer feedback supplements but does not replace your own verification. |
| "I can commit before the reviewer approves" | Code must only be committed after milestone approval — reviewers evaluate uncommitted diffs. |

## Red Flags - Stop and Correct

- You are about to run any `superpowers-codex` command.
- You are pushing commits without user approval.
- You did not announce which skill you invoked and why.
- You are proceeding to review with failing lint/typecheck/tests.
- You are skipping the worktree and working on the main branch.
- You are applying a reviewer suggestion that contradicts user requirements.

## Verification Checklist

- [ ] Plan folder located and all required files present
- [ ] Reviewer configured or explicitly skipped
- [ ] Max review rounds confirmed (default: 10)
- [ ] Worktree created with branch `implement/<plan-folder-name>`
- [ ] Worktree directory verified in .gitignore
- [ ] Baseline tests pass in worktree
- [ ] Each milestone: stories tracked (in-dev -> completed)
- [ ] Each milestone: lint/typecheck/tests pass before review
- [ ] Each milestone: reviewer approved (or max rounds + user override)
- [ ] Each milestone: committed locally only after approval
- [ ] Each milestone: marked approved in story-tracker.md
- [ ] All milestones completed, approved, and committed
- [ ] Final test suite passes
- [ ] Worktree branch merged to parent and worktree deleted
- [ ] Story tracker updated with final status