The Codex desktop app

Use Codex on your computer to understand a website project, make one small change, and review the result. The original Codex desktop app is now part of the ChatGPT desktop app; these instructions use the current Codex view.

Before you start

• The current ChatGPT desktop app for your operating system, installed from the download link in OpenAI’s desktop app documentation.
• A ChatGPT account with Codex access, or a supported API key sign-in for local work. A managed workspace may require your administrator to enable access.
• A local copy of a website project you can edit, with its normal development tools installed and its startup instructions available.
• A saved copy or Git checkpoint of your current files, including any unfinished work. Pick a small first task, such as changing one button label.

Want to do it yourself?

Difficulty

4 out of 10

Estimated completion time

30–60 minutes

Skills you’ll need: Choose a project folder, describe one small change, read the diff, and check the website preview.

I’ll do it myselfI’d rather get help

How this helps your brand

Reviewing a small website change in both files and a preview helps keep the message and customer action aligned. Saving a checked version gives the next update a dependable starting point.

1. 1

   Step 1: Open the app and choose Codex

   Open the ChatGPT desktop app and sign in. Choose Codex, then start with New chat. If you used the older standalone Codex app, OpenAI says existing users can update while keeping their projects and settings.

   Check the account and workspace before you begin. If Codex is unavailable in a managed account, ask your administrator about local Codex access. Reinstalling the app will not grant workspace permissions.

2. 2

   Step 2: Connect the folder that contains your website

   Open your website folder as a local project. A folder-backed project gives Codex access to real files on your computer. A ChatGPT project containing uploaded sources is a different kind of context, so confirm that your local project has the website folder attached.

   In an existing local project, use its menu, choose Edit project, and inspect the attached folders. If necessary, use Add folder to attach your website. The primary folder is where new chats start.

   Send a first message asking Codex to identify the project folder, explain the website’s structure, and find the documented startup and check commands without changing files. Compare the folder and page names in its answer with your own files.

   Tip: If you see a folder full of several projects, select the specific website folder before asking for edits.

   Illustrated exampleAttach the website folder, then recognize its files

   Illustrated local project · Northline website

   Parent folder/Projects

   • northline-siteAttach this folder
     • README.mdStartup instructions
     • index.htmlHome page
     • styles.cssAppearance
   • another-projectSeparate website

   Confirm the attached path matches

   First chat: inspect before editing

   “Identify the project folder, explain the website structure, and find the documented startup and check commands. Do not change files yet.”

   Compare the answer with /Projects/northline-site and the files above.

3. 3

   Step 3: Describe one change you can check

   Choose something with a visible before and after. For example: on the home page, change the button text from “Learn more” to “See our services” while keeping its destination and appearance the same.

   Paste the prompt below and replace every bracketed field. Include the page, the exact old and new wording, and how you will check it. Ask Codex to preserve unrelated work and to use the project’s existing commands rather than inventing a new setup.

   Codex can edit files and run commands within its permissions. Read any access request and approve only the access the task needs. If a command is blocked, ask which part is unavailable and whether you can run the existing command yourself.

4. 4

   Step 4: Read the changed lines and check results

   Use the app’s review pane to inspect the changed files. For the button example, the diff should show the intended wording change without a redesign, a new dependency, or a different link destination.

   Read the final report for commands actually run and their results. “I recommend running the tests” means the tests still need to be run. Ask Codex to distinguish a failed check from a check it could not start.

   If unrelated lines changed, name the file and unwanted change in a follow-up. Ask for a focused correction while preserving your other edits. Review the new diff before moving on.

   Illustrated exampleA small request should produce a small, explainable diff

   index.htmlExample review · one label change

   Removed<a href="/services">Learn more</a>

   Added<a href="/services">See our services</a>

   Changed

   “Learn more” → “See our services”

   Preserved

   Destination: /services
   Existing styling and surrounding content

   Read the check report literally

   Passed

   HTML validation ran successfully.

   Not run

   Browser check: open Home, click the renamed link, then repeat at phone width.

   The diff confirms the edit. The preview confirms the page and link work.

5. 5

   Step 5: Open the website and test the original behavior

   Start the website with its documented command, or use the preview that is already running. Open the page you named and confirm the new wording. Click the button and check that it still opens the original destination.

   If the page still shows the old version, first confirm that the preview belongs to the folder Codex edited. Then reload it. Give Codex the exact preview address, page, and what you still see if the mismatch remains.

   Try the same page at a narrow phone width. When the visible result and the file changes are right, save a new working copy or Git checkpoint. The task is finished when you can demonstrate the change yourself.

Make one small change in this local website project.

Page: [page or route]
Current behavior or wording: [exact current behavior or text]
Desired behavior or wording: [exact replacement]
How I will check it: [specific page, action, and expected result]

First confirm the project folder and find the relevant files and documented check commands. Make the smallest change needed, preserve unrelated edits, and keep the existing design and behavior outside this request. Run the relevant existing checks where available. Finish with the changed file names, checks actually run and their results, anything you could not verify, and the preview steps I should follow. Do not commit or publish.