Enable Apple Intelligence when starting up from an external drive.
If you’ve moved your system to an external drive, Apple Intelligence normally won’t work, but there’s a workaround. Here’s how to enable it.
In our previous article we showed you how to enable Apple Intelligence and the ChatGPT extension on your Mac. But if you want to start up your Mac from an external drive and use Apple Intelligence, you’ll be blocked.
While you can still use Siri while booted into an external drive, Apple Intelligence will be disabled.
This is mainly for security reasons: if you use an external drive in some other location or facility, your drive may be connected to an external network – which may or may not contain malware or vulnerabilities you’re not aware of.
Or you might leave a Mac workstation unattended by accident with your external drive attached where others may have access to it. For these reasons Apple disables Apple Intelligence when your Startup Disk is an external drive.
The other reason Apple disables Apple Intelligence on external drives is it consumes a lot of system resources. If the external drive is connected to a Mac over USB it may cause performance problems – as USB is a relatively slow connection standard compared to Thunderbolt.
Another issue is that Apple also disables Apple Pay on external drives on the Mac (also for security reasons). Apple Intelligence also isn’t yet available in some countries such as in the EU and in China.
Apple Intelligence is disabled by default when booting from external drives.
How macOS determines features
macOS includes a system process called eligibilityd which uses several inputs to determine which features are allowed or not allowed. These include the locale, language in use, country code, boot parameters, and more.
To store this info macOS keeps a folder named “eligibilityd” located on the Startup Disk at /private/var/db. Inside this folder there are three items:
- domains.data
- eligibility_inputs.plist
- eligibility.plist
Note that the /private alias and all the subfolders it points to are hidden by default in macOS, and to be able to see them in the macOS Finder, you’ll need to enable hidden files (or use the Terminal app).
The second two items in the eligibilityd folder are .plist (property list) files. .plists are simple XML files which contain key/value pairs and are often used in macOS to store settings.
The eligibility_inputs.plist file contains close to one-hundred items, mostly compound dictionaries of other items such as lanuage, locale, time, etc.
One item in this file is named “ExternalBootDriveInput”, and it cotains an array of three items, the first of which is also named “ExternalBootDriveInput”. The second item in the array is named “EligibilityInput” which denotes that this item is one of the inputs for eligibilityd.
The third item in the array is an object of type NSObject – the base object class for many higher level objects in macOS (“NS” stands for “NeXTStep – macOS’s predecessor OS from NeXT, Inc.).
The other file (“eligibility.plist”) contains info as to whether your Mac is booting from an external drive or not (along with other settings). macOS reads the contents of these files to help determine which features to enable or disable.
Viewing the .plist file in Apple’s Xcode.
Enabling Apple Intelligence on an external drive
There are several proposed workarounds for the external drive issue, which mainly consist either of modifying the .plist files, using Terminal in recovery mode, or using third party tools.
These methods are:
- Disable SIP
- Download a replacement eligibility.plist file
- Use third party tools
For System Integrity Protection (SIP), you’ll need to boot your Mac into recovery mode, run the Terminal app, and use the csrutil command line utility to turn off SIP. We haven’t tested this method.
The second method (downloading a replacemrnt eligibility.plist file from the internet) involves downloading a modified replacement, removing the original file in the /private/var/db/eligibility folder, installing the new file, and setting its permissions (something we won’t get into here).
Several online users have posted modified eligibility files which contain changes to some of the values in the .plist file. We can’t vouch for the correctness of these files either.
These changes seem to involve setting the OS_ELIGIBILITY_CONTEXT_ELIGIBLE_DEVICE_LANGUAGE key’s value specifically to “en-US”, and adding a second subkey OS_ELIGIBILITY_INPUT_DEVICE_AND_SIRI_LANGUAGE_MATCH.
Once the new file is in place you’ll need to do a File->Get Info on it in the Finder, and in the Get Info window under General: you’ll need to check the Locked checkbox to prevent macOS from overwriting the file if you’re booting from an external drive.
Be sure not to check this setting on the copy of the file on your internal drive containing macOS.
Set the external drive containing the modified file as the Startup Disk in the System Settings app and restart your Mac.
Now when you open the System Settings->Apple Intelligence & Siri pane you should be able to turn on Apple Intelligence in the settings.
Other online users such as Kyle Ye have developed tools which perform modifications to your Mac to make it easy to change various eligibility settings. To use them you’ll also need to know how to use the macOS Terminal app.
While these tools appear to work fine, use them at your own risk. At the very least back up all your data first. Remember — you’re modifying the operating system and things can go wrong.
The instructions for these tools can be a bit daunting for non-technical users, and there’s always a chance you might damage your Mac’s software by making mistakes in Terminal, so be careful.
You may want to create a separate macOS Sequoia 15.2 test volume if you decide to try any of the above methods on your Mac.
