Download Scalpel-macos-arm64.dmg from scalpeltrade.com/download, open it and drag Scalpel onto the Applications folder in the window that appears. Open Scalpel from Applications. It is signed and notarized by Apple, so macOS only asks once whether you want to open an app downloaded from the internet. Scalpel runs on Macs with Apple silicon (M1 and later), not on Intel Macs.
Scalpel for macOS is a normal app bundle in a disk image: no installer, no background helpers, nothing outside Applications except its settings folder. Updates install themselves from inside the app.
Before you start
A Mac with Apple silicon. Check under Apple menu > About This Mac: the Chip line should say Apple M1 or later. Intel Macs cannot run Scalpel.
An Interactive Brokers account, with TWS or IB Gateway installed on the same Mac (guide 1.4).
Your licence key, or buy one when Scalpel asks. The download is free; the app needs a key to open (guide 1.3).
Install it
01
Download the disk image
Go to scalpeltrade.com/download and click Download for macOS. You get Scalpel-macos-arm64.dmg. The same download is on your account page under Download.
02
Open it and drag Scalpel to Applications
Double-click the DMG in Downloads. A window called Scalpel opens with the app on the left and a shortcut to your Applications folder on the right. Drag Scalpel onto Applications.
Scalpel
ScalpelApplications
Simplified. The disk image window: drag Scalpel onto the Applications folder.
03
Eject the disk image
In Finder's sidebar, click the eject button next to Scalpel, or drag the disk to the Bin. You can delete the DMG from Downloads.
04
Open Scalpel from Applications
Open Applications and double-click Scalpel (or press Cmd+Space and type Scalpel). The first time, macOS says Scalpel is an app downloaded from the internet and asks if you are sure you want to open it. Click Open. Apple has checked the app (that is what notarized means), so this is the only question.
05
Activate and connect
After a short splash (click or press any key to skip it), Scalpel shows the licence screen. Paste your key and click Activate (guide 1.3), then connect to TWS or IB Gateway (guide 1.4).
Activate Scalpel
Paste your licence key. It is on your account page and in your purchase email.
SCLP-7K3M-Q9XD-2HTF-W8RBActivate
Already bought one?Find my key
No licence yet?One payment covers two computers and every update, with a 7-day refund. Buying takes a minute at scalpeltrade.com; your key arrives straight away.
Buy a licence
This computer: TRADING-PC. Each licence covers two computers; free one up on your account page.
The licence screen on first open. This computer's name, at the bottom, is how it appears on your account page.
If macOS blocks the first open
If you see that Apple could not check Scalpel, or that it "cannot be opened", you most likely have an older or incomplete download. Delete it, download the DMG again from scalpeltrade.com and repeat the steps. If it still refuses:
Close the warning.
Open System Settings > Privacy & Security and scroll down to Security.
Next to the line about Scalpel being blocked, click Open Anyway, then confirm with your password or Touch ID.
Only do this for a file you downloaded from scalpeltrade.com.
Keys on a Mac
Every guide writes keys the Windows way. On a Mac, Ctrl is Cmd throughout: Cmd+X sells half, Cmd+Z sells the full position, Cmd+, opens Settings, Cmd+0 resets the zoom. Shift keys are the same on both: Shift+1 buys preset 1. The one exception is Cancel all orders: Cmd+Q quits a Mac app, so on a Mac it is Shift+Q. See guide 4.3 for the full list.
Where Scalpel keeps your files
Settings and data live in your user Library, so replacing or moving the app never loses them:
To get there, in Finder press Cmd+Shift+G and paste ~/Library/Application Support/scalpel.
Update or remove it
Update: Scalpel downloads updates by itself and shows Update ready in the status bar. It never restarts while you hold a position, a working order or a live stop (guide 12.2).
Second computer: install it there and paste the same key; a licence covers two computers (guide 12.1).
Remove: drag Scalpel from Applications to the Bin, then delete ~/Library/Application Support/scalpel if you want your settings gone. Free the computer on your account page so the slot is available again.
What can go wrong
"You can't open the application" on an Intel Mac. Scalpel is built for Apple silicon only. There is no Intel build.
Updates fail. Scalpel is not in Applications (for example it runs from the DMG or from Downloads). Move it to Applications (guide 13.11).
No Start TWS button in the connection banner. Scalpel looks for TWS and IB Gateway in Applications (yours or the Mac's). Installed elsewhere, start them yourself (guide 1.4).
Questions
Does Scalpel run on Intel Macs?
No. Scalpel is built for Apple silicon (M1 and later) only. Check Apple menu, About This Mac: the Chip line must name an Apple M-series chip.
Is the Mac app signed and notarized?
Yes. It is signed with an Apple Developer ID and notarized by Apple, so macOS only asks the usual once-only question about an app downloaded from the internet.
Why does Cmd do what Ctrl does in the guides?
Scalpel uses the platform's command key: Ctrl on Windows, Cmd on a Mac. Every Ctrl shortcut in the guides is Cmd on a Mac, except Cancel all orders, which is Shift+Q on a Mac because Cmd+Q quits the app.
Can I run Scalpel from the disk image?
It opens, but do not. The disk image is read-only, so updates cannot install, and the app vanishes when the image is ejected. Drag it to Applications.
Can one licence cover my Mac and my Windows PC?
Yes. A licence covers any two computers, on either system. Paste the same key on both.