# Planning with Codex

Run a multi-round plan debate between Claude and Codex to produce a sharper implementation plan.

For high-stakes features it is sometimes worth having two planning models argue with each other before you commit. ClosedLoop provides this via `/code:plan-with-codex`, which runs a bounded debate between Claude's `plan-agent` and Codex (default `gpt-5.3-codex`).

## The command

```
/code:plan-with-codex [--max-rounds N] [--plan-file PATH]
                      [--codex-model MODEL] <prompt>
```

Debate rounds are capped by `--max-rounds` (default 15). The output is `debate-plan.md`.

## How the debate runs

1. `plan-agent` (Opus) drafts an initial plan from the prompt.
2. Codex reviews the draft, raises objections, and proposes changes.
3. `plan-agent` either accepts, counters, or rewrites.
4. The debate continues until convergence, a clear disagreement is reached, or `--max-rounds` is hit.

Each round's state is persisted in three sidecar files so the debate can be resumed:

- `{stem}.state`
- `{stem}.prompt`
- `{stem}.exclusions`

## Prerequisites

- `codex` must be on your PATH or configured under **Settings → CLI Tools**.
- The `code:codex-review` skill must be installed (it is, if you ran the one-line plugin installer).

## When to use it

- Architecturally consequential features where you want an adversarial review before implementation.
- Plans that have failed judge evaluation repeatedly.
- Migrations and refactors where a second model's take can catch a whole-system risk.

## When to skip it

- Small, well-scoped features. The debate adds real token cost; use it where it pays off.
- Any case where your PRD is still vague. Fix the PRD first.

## Integration with the main workflow

The resulting `debate-plan.md` is a standalone artifact. To bring it into the main loop, promote it to `plan.md` (or run `/code:code` with `--plan <debate-plan.md>`). From there, the standard 18-phase flow takes over.