# GPT (Codex)

The model behind the second executor: heavy autonomous coding, big refactors, and the adversarial pass on every done claim.

## What it is
The model the second executor runs on. It handles the heavy autonomous coding — sweeping refactors, multi-file features, grind-to-completion build loops — and plays devil's advocate on completion claims, attacking the claim with fresh eyes and no stake in it being true.

## Why
A different lab's model has different blind spots than the ones that write my code. That independence is what makes its review pass worth having — it fails differently, so it catches differently.

## How Andrew uses it
It gets a written spec, a bounded scope, and room to grind. Its output never ships unreviewed: the primary session reads the diff, runs the tests, and looks at the result. Two strong models with different failure modes catch more than either alone.

## How to get it
Comes with the Codex CLI (`npm i -g @openai/codex`). The transferable idea is a second frontier model as executor and skeptic, not the specific one.

_Distilled from: method/models/codex-gpt.md_
