What never to type into Claude

Claude is safe to talk to about almost anything. But a chat is a place where text gets stored, read back, and sometimes copied. Some things should never be there. This is the one list in this guide to memorize.

Why

Claude doesn't need any of these to help you. It never needs your password to explain a screen, and it never needs your credit card number to plan a price. If a message seems to need one, something is wrong with the plan, not with the rule.

Chats are also kept, so you can scroll back. Anything you paste stays there. Anyone who ever sees your screen, or your account, sees it too.

What to do instead

• Say that you have it, not what it is. "I have the key from the service now. Where does it go?" is enough.
• Later, Claude shows you a safe place for secrets. When your app needs a key (Part 8), Claude gives you a command with a hidden prompt: a question in the Terminal pane that takes the key without showing it. Or it points you to the settings page on the service's own website. You paste the key there: never in the message box, and never in a file in your project. You also keep a copy in your password manager.

• Describe other people loosely. "A regular customer who collects one game" instead of their name and address. Claude plans equally well.

• Payment pages are different from chats. Typing your credit card into Claude's own payment page, or Apple's, is normal. It's the chat box that is off limits.

If Claude ever asks you for a password or a code in the chat, say no and tell it to find another way. It will.

If you already pasted one

Don't panic. Change that password today. If it was a code, it expires on its own in a few minutes. If it was a secret key, go to the service that gave it to you and ask for a new one. The old one stops working. Then delete the chat: hover over it in the sidebar, click the three dots, then Delete.

A message you can send at the start of any chat where secrets might come up: