tabcatHow Tabcat works
Tabcat keeps a strip of tabs on the edge of the window in front: left, right, top or bottom. Here is how to set it up, how to read the strip, and every setting and shortcut.
Set up
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Add your accounts
Click + on the strip, choose Claude Account… and name it after the account, like work or client. Tabcat starts a copy of Claude just for it, with its own data, so each account signs in on its own.
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Sign in once in each copy
Sign in as you normally would. Tabcat makes sure the sign-in comes back to the copy that started it, even with several copies open.
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Add the apps you switch between
Click + again and pick an app under Apps with a Window Open, or use App from Applications… and Apple App… to find others. Clicking an app's tab brings its window forward in the same spot.
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Group tabs into Sets
Click the pill at the top of the strip and choose New Set… to make one. A Set holds one kind of work, like a client's accounts and the apps you use for them.
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Allow Accessibility and Automation
macOS asks the first time Tabcat needs each one. Accessibility lets Tabcat move and resize windows when you switch tabs. Automation lets it ask an app to show its window.
Reading the strip
Each tab's tile shows its state by shape and fill, so you can read it without relying on colour.
| Tab | State | What it means |
|---|---|---|
| In front | Filled with the tab's colour, with its name in bold. The window's edge takes the same colour. | |
| Open | A paler fill. The app is running behind the one in front. | |
| Not started | A dashed outline. Click it to start the app. |
When the strip is shorter than its tabs, it scrolls. A small arrow above or below shows there are more tabs that way.
Shortcuts
| Keys | What it does |
|---|---|
| Control CommandTab | Hold ⌃⌘ and press Tab to step through the tabs in the current Set, most recent first. Let go to switch. |
| Shift | While stepping, add Shift to step back. |
| Control Option 1 to Control Option 9 | Switch to your Sets, in order. |
| Control Option 0 | Show all tabs. |
Turn either group of shortcuts off in Settings › General. Right-click a tab to switch to it, hide or quit its app, edit its name and icon, choose its Sets, or remove it.
Appearance
Settings › Appearance changes how the strip looks. Try them here: the strip beside the settings sits on a dark app.
Strip
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Colour Match the window takes the colour of the app beside it.
- Show tab names
- Colour the window's edge with the active tab
Mailbox
Coming soon
When the mailbox arrives, an envelope will appear above the gear if yowl is installed. Its number will count unread mail, and a tab will get a red dot when the agent with its name has written to you.
You'll click a message to read all of it and reply, and start new messages to any of your tabs or anyone who has mailed you. Agents will reach you in yowl as “owner”.
Without yowl, Tabcat shows no mail at all. With it, you'll be able to turn the mailbox off in Settings › General. Tabcat then stops checking for mail, and yowl keeps working for your agents.
Signing in
Claude finishes a sign-in by having your browser open a claude:// link back to the app. With several copies of Claude running, macOS hands that link to just one of them, often the wrong one.
So when a copy starts signing in, Tabcat takes claude:// links for up to 3 minutes and passes the sign-in link to every running copy. Each copy accepts only a sign-in it started, so exactly the right one acts on it. Claude gets claude:// links back once the sign-in link arrives, when the time runs out, or when Tabcat quits. Any other claude:// link goes to the copy of Claude in front.
To start a sign-in by hand, open Settings › Tabs, pick the account and choose Sign In with Browser… there. Tabcat then holds claude:// links for 10 minutes.