Permission Modes and How to Undo a Mistake

Here's the reassuring part: out of the box, Claude Code can't change anything without your say-so. It asks first, every time.

When Claude wants to edit a file or run a command, it stops and shows you exactly what it plans to do, then waits. You'll see the change laid out, with an option to approve or reject it. Nothing happens to your files until you approve. This is the default, called Manual mode, and it's the right setting while you're learning.

Saying no is a normal, expected move. If a proposed change looks wrong, reject it. Claude will ask how you'd rather it go, and you steer from there. You're never stuck with its first idea.

Two things worth knowing by heart:

Stop it mid-task. If Claude starts down the wrong path, press the Esc key. It halts right away. You can then type a correction, and it picks up from your new direction instead of finishing the thing you didn't want.

Undo a change. If you approved something and then thought better of it, just tell Claude:

undo the change you just made

It knows what it changed in this session, so it can put it back. This works best for something it just did; the further back you reach, the less reliable it gets.

That's the honest limit, so here's the one habit that makes all of this stress-free: back up anything precious before you start. Copy the folder, or make sure it's synced to iCloud or Dropbox. Then even a mistake you don't catch is a quick restore, and you can experiment freely.

As you get comfortable, you can loosen the reins with other permission modes that ask less often. But there's no rush. Manual mode, a calm eye on each change, and a backup is a setup you can trust.

Try this now: start Claude Code, ask it to rename one file, and when it shows you the plan, click reject just to feel how the approval step works. Then approve a second try.

Where to go next: Your First Real Win puts this to work on a real folder, and Give It Instructions, Not Code helps you avoid mistakes in the first place. The official Claude Code quickstart walks through the permission prompts and the review step in more detail.