When there’s no connector, Claude uses your computer

What it is

Most of the time, Claude gets into your tools through a connector (the Connectors section in Settings). But not every app can be connected that way. Plenty of desktop apps have no connector and no web version at all.

Computer use fixes that. Claude takes screenshots of your screen, works out where it needs to click and what it needs to type, and then does it, the same way you would.

The steps

This is the reel, written down.

1. Switch it on

   In the Claude desktop app, go to Settings → General and turn on computer use. On a Mac, it also asks you to allow Accessibility and Screen Recording in System Settings the first time.

2. Tell it the app and the job

   Open a new chat and tell Claude which desktop app you want it to work in, and what to do there.

3. Give it permission

   Claude asks before it touches each app. Choose Allow for this session. It asks again every time you start a new session, so it can never quietly reach an app you didn't approve.

4. Let it work

   Your screen shows an orange border while Claude is in control. Hands off the mouse until it's done.

Try it in two minutes

Two apps with nothing at stake: the calculator and a notepad.

Open the Calculator app and work out 20% VAT on a £4,250 invoice, and the total including VAT. Then open Notepad and write: "Invoice total: £[total], of which £[VAT] is VAT." Use the apps on my screen, don't just do the maths yourself.

You should end up with £850 VAT and a £5,100 total. On a Mac, swap Notepad for Notes.

The thing to be careful of

Because Claude works from screenshots, computer use burns through a lot of your usage, it's slower than a connector, and it can still get things wrong.

1. Don't use it on anything sensitive. No banking, no payroll, nothing where one wrong click costs you money or exposes a client.
2. Do use it on low-stakes apps. Apps where a mistake has little to no consequence, like a notepad or a calculator, are fine.
3. Tidy your screen first. Close your email and anything with client details on it. Claude can see whatever's on the screen.

What you need

1. A Pro or Max Claude plan. Team and Enterprise plans don't have computer use yet.
2. The Claude desktop app, on Mac or Windows.
3. Your computer awake, with the Claude app open, while it works.

Trading and crypto apps are blocked by default, whatever you ask.

Where this goes

Now Claude can reach the apps that have no connector. Next, Day 18 puts it to work on the job most owners hate most: the inbox.