Get started with Codex: complete your first task with one file

Choose a small task whose result you can check, such as extracting action items from meeting notes, finding common points across several texts, or renaming files consistently. Start with one familiar task instead of trying to complete a large report at once.

This guide uses a short note called meeting.txt. The filename is an example; substitute the name you actually prepared. A text file works well for a first exercise because you can inspect it without special conversion tools.

OpenAI's current documentation describes selecting ChatGPT or Codex in the ChatGPT desktop app. Install the app for your operating system using the official download instructions, sign in and select Codex. If your existing installation looks different, compare it with the official guide below.

This exercise uses a desktop environment with a folder on your computer. You can also work with files using the Codex CLI in a terminal or an editor extension, but where you start and view the results will differ.

Create a folder on your computer, such as codex-practice, and put a copy of the notes you want to practice with inside. Connect that folder to a local project in the app. A project brings related work and materials together; connecting a local folder lets you work with its files.

A short note without personal information is enough. For example: ‘Prepare a draft event announcement by Friday. Decide who is responsible at the next meeting.’ There is no need to add unrelated folders for this exercise.

Start with: ‘Tell me the current working folder and the names of the files inside it. Do not change any files yet.’ Once you can see the note you added, move on to the next task.

Example request: ‘Read meeting.txt and organize the decisions and action items separately. Include an owner and due date for each action item. Mark information absent from the note as undecided. Keep the original and save the result as output/meeting-summary.txt.’

This explains which material to use, what to create and where to save it. You do not need to specify the order of file reads or internal commands. Instead, explain how to handle details that would be troublesome to get wrong, such as names or deadlines.

If Codex asks for confirmation, read which file or action it concerns and check that it matches your request. If it unexpectedly needs an external account connection just to organize a document, ask why.

Open the result link or find meeting-summary.txt where it was saved. Confirm that the file exists and read it beside the original note. For example, check that ‘decide who is responsible at the next meeting’ was not turned into an action item for a specific person.

If something needs changing, continue in the same task. Identify the mismatch: ‘Keep the deadline wording from the note. Do not turn Friday into an arbitrary date.’

Finally, ask: ‘Tell me the paths of the files you created and anything you could not verify.’ Check both the quality of the summary and that the file was saved correctly.

You can continue in the same task to change the format of the same note. For a different deliverable, a new task can be easier to find later. Give it a descriptive name such as ‘Organize September event meeting notes.’

After repeating a process a few times, you can turn instructions you keep adding into a skill. There is no need to install several skills and plugins at the outset. Become comfortable reading files and checking results first, then add what you need.