DuelPlan

Adversarial plan review for Claude Code. Claude drafts a plan, Codex CLI tears it apart, Claude revises, repeat until stable.

How It Works

Instead of drafting a plan once and hoping for the best, DuelPlan runs an automated critique loop:

1. Claude drafts an implementation plan based on your prompt and repo context
2. Codex critiques the plan adversarially — finding gaps, bad assumptions, missing edge cases
3. Claude revises based on the critique
4. Repeat until the plan converges (max 5 rounds)

Issues are rated by severity (CRITICAL / MAJOR / MINOR). The loop exits when only minor feedback remains. You get the full critique history so you can see how the plan evolved.

Prerequisites

• Claude Code
• Codex CLI installed and configured

Installation

Register the marketplace first:

/plugin marketplace add DevStrategist/duelplan

Then install:

/plugin install duelplan@duelplan

Usage

Ask for extra rigor on any plan:

• "use duelplan"
• "I want adversarial review on this plan"
• "give this plan extra scrutiny"

The skill activates automatically when Claude detects you want a more rigorous planning process.

Works Great With

We recommend Superpowers to level up the planning and development stages for both Codex and Claude Code. DuelPlan handles adversarial review of plans; Superpowers handles the broader workflow — brainstorming, TDD, execution, code review. They complement each other well.

What's Inside

Skills

• duelplan — Adversarial critique loop between Claude and Codex CLI

License

MIT License — see LICENSE for details.