Setup & Installation
npx skills add https://github.com/garrytan/gstack --skill codex
https://github.com/garrytan/gstack/tree/main/codex
View on GitHubWhat This Skill Does
Wraps the OpenAI Codex CLI to provide three code analysis modes: a structured diff review with a pass/fail gate, an adversarial challenge that searches for edge cases and failure paths, and a consult mode for open-ended questions with session continuity across turns.
Using two independent models on the same code catches findings that either one alone would miss, since Codex and Claude have different training and different blind spots.
When to use it
- Getting a P1/P2-tagged diff review with a hard pass/fail gate before merging
- Running adversarial challenge mode on auth changes to find injection vectors and bypass paths
- Asking follow-up questions about a codebase decision across multiple turns with session memory
- Comparing Codex findings against Claude's own review to surface gaps each model missed
- Sending a plan file to Codex for a second opinion on logical gaps before implementation starts