---
title: Set up Codex
description: Minimum Codex setup for a research project.
reviewedOn: 2026-09-08
sourceRefs: [openai-codex-quickstart, evidence-lab-methodology]
---

## Result

The ChatGPT desktop app is installed, Codex is working in the intended primary folder, and a new task can discover the project's root `AGENTS.md`.

The current [official Codex quickstart](https://learn.chatgpt.com/docs/quickstart) lists desktop support for macOS, Windows, and Linux. It also distinguishes Codex for software-development work from ChatGPT Work for research, analysis, and office deliverables. Choose the surface that matches the task; this Evidence Lab route uses Codex when the workflow needs file and project tooling.

## Actions

1. Install the ChatGPT desktop app for your operating system from the official quickstart and sign in with the approved ChatGPT account.
2. Start a local project or open the dedicated project folder. If a project contains several folders, make the intended repository the primary folder because Git operations and automatic `AGENTS.md` discovery use it.
3. Review the task's permission level before adding files or allowing commands; grant only what the first scenario needs.
4. Add the de-identified practice material to `inputs/` and keep credentials out of the project and chat.
5. Create `AGENTS.md` at the primary folder root. Include the project goal, data boundary, input and output locations, required checks, confirmation boundaries, and handover format.
6. Start a new Codex task and ask it to identify the working folder and restate those rules before requesting any change.
7. Run a read-only orientation step: ask Codex to list the permitted inputs and the checks it will use. Correct any mismatch before the first working task.

## Check

In a fresh task, Codex identifies the correct primary folder, finds the root `AGENTS.md`, names the goal, permitted inputs, expected output, required checks, and actions that need confirmation. It does this without copied context from an earlier task.

## If it fails

Confirm that the intended folder is primary, the filename is exactly `AGENTS.md`, and the rules are within that folder's instruction scope. If discovery still fails, open a fresh task from the folder and test again. Never solve discovery by placing secrets or private case evidence in the instruction file.

**Next:** [Organise the workspace](/en/start/workspace/).