First App.
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CHAPTER 06Lesson 21 of 36

Save and restore working versions

Keep a way back before making a big change.

In Codex5 min read & do
By the end of this lesson

Create a named checkpoint and know how to recover it.

Let’s do this

  1. 1
    In Codex

    Start from something that works

    Run your main checklist. A checkpoint is most useful when you know what it contains and what worked. Ask Codex to list any outstanding changes first.

  2. 2
    In Codex

    Save a named checkpoint

    Ask Codex to make a local Git commit. Git is a history of your project files; a commit is a named checkpoint. You do not need to publish the code on GitHub. Ask it to exclude passwords, private keys and build output.

  3. 3
    In Codex

    Make one change after the checkpoint

    Give Codex a small task. Test it. If the result is good, save another checkpoint with a name such as “Add plant works and survives restart”.

  4. 4
    In Codex

    Recover carefully when needed

    Ask Codex to explain the files it would restore and preserve current work before undoing anything. Prefer a reversible restoration. Do not blindly run a command that discards all changes or deletes the project folder.

Xcode source-control history with the main branch, two saved commits and the selected code change.View larger
Apple’s current guide uses this example. Your app’s name and version will differ.Screenshot source (opens a new tab)

A message for Codex

Check the current changes in my first iPhone app. Explain what works and what is untested. If the app passes our main checks, save a local Git checkpoint with a clear description. Exclude secrets and generated build files. Do not publish the repository. Show me the checkpoint name and explain how we could safely restore it while preserving later work.

Make this message fit your idea.

What you should see

You have a named checkpoint and know which app behaviour it contains. Restoring it is a deliberate choice, not a guess.

A couple of words, explained

Git
A tool that keeps a history of changes to your project files.
Commit
A named checkpoint in that history.

If you get stuck

Go at your own pace. There is no test to pass.

Checked 7 September 2026. Screens can change; the official guides below have the latest steps.

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