Updating Loop

When a new version of Loop is released, you can click HERE to read what features or fixes were a part of the new release.

The process to update is very similar to the original building of Loop app, except you get to skip a couple of the early steps. The update steps are:

  1. Update macOS, Xcode, iOS, and/or watchOS
  2. Download updated Loop code
  3. Open in Xcode, sign targets
  4. Add optional code customizations
  5. Build onto your iPhone
  6. Resolve Build Errors

You do not have to delete your existing app. The new app update will simply overwrite the old app and save all your old settings and information.

When to Update

You will have to rebuild your Loop app at a minimum once every 12 months. The apps built and signed by you in Xcode with a paid developer account will only last for 12 months before they expire and need rebuilding. So, at least once per year you will have to rebuild your app and go through this update process.

Under ordinary circumstances, you do not have to update your Loop app until you are ready to grab new features. However, we encourage regular updates when a new version is released because they often contain bug fixes or improvements which may increase operational stability.

Step 1: Update macOS and Xcode

Omnipod and iOS 12.2 users

If you are going to use either Omnipod-testing branch, Dev branch, or iOS 12.2, you will need to update to macOS 10.14.3 (Mojave) at a minimum. After you update your macOS, make sure you grab updated Xcode of 10.2 at a minimum. Both those updates are required.

Update to Homebrew and Carthage

For people who have already built Loop before, there's an extra step needed for your first update since the recent round of updates. We need you to update Homebrew and Carthage, but this is quick and easy. Please open Terminal app and copy & paste the following brew update && brew upgrade carthage. When the update finishes, you should have carthage 0.33.0 (or later) installed. If you don't see the version, you can use carthage version to have the version displayed.

If you don't have 0.33.0 installed at a minimum, then you will need to use brew link --overwrite carthage and then repeat the brew update && brew upgrade carthage command. That should succeed in updating you properly, and you can again check that with carthage version.

Between Loop app builds, there's a high liklihood that Apple has updated one or more of the systems involved in your Loop app. If you miss macOS or Xcode updates, you may run into build problems. Do not skip these steps before updating Loop.

Step 2: Download Updated Loop Code

After you've finished the updates to your devices listed above, you can move onto downloading updated Loop code. You will not be simply using your old downloaded Loop code (and in fact, you can delete those old folders now if you want). Click on ONE of the links below to download an updated versions of Loop code:

Loop: Master branch


Loop: Dev branch


Loop: Omnipod-testing branch


Best practice is to leave your Loop code in your Downloads folder. If you store your Loop code a different folder than Downloads (such as your Documents folder or Desktop), make sure the specified folder is not an iCloud drive. Storing your Loop code in an iCloud drive folder will prevent Loop from building successfully. How do you know if a folder is an iCloud drive? Check your System Preferences. If your System Preferences for iCloud is set as shown below, your Documents and Desktop folders are iCloud drives and NOT appropriate places to save your Loop download.

Depending on your browser and settings, your Loop download may or may not automatically unzip. If it does not unzip automatically, you can right-click on the zip file and choose to "Open With" Archive Utility. This will create a blue folder called Loop-master. HOWEVER, if you already have an existing Loop-master folder from a previous download, the name of the next download will be something like Loop-master (1). The problem with that folder name is that it contains a space...and spaces in the name will cause your Loop build to fail. So, either delete old copies of Loop before downloading/unzipping or rename the folder(s) to ensure that NO SPACES are in the folder name.

Step 3: Open in Xcode, Sign Targets

Double click the Loop folder in your Downloads folder, and then double click the Loop.xcodeproj to open the Loop project in Xcode. Navigate, as you did when you originally built the app, to the four target areas. Sign the four targets with your developer team name. Remember that the "(personal team)" in the signing team's name indicates that is a free account and the app will only last for 7 days if you sign with that team name.

Step 3: Add Code Customizations

Add or redo any code customizations, if needed. These will not be carried over automatically from the old app. Be sure to read up in the code customizations section before building, as there may be new customizations available since the previous build.

If you are building with a free account, you will have to remove the Siri capabilities in order to build.

Step 4: Build to your iPhone

Plug your iPhone into the computer, unlock it so that the phone does not fall asleep during the build process. You can find this setting under Settings, Display & Brightness, Auto-Lock, set to "Never". You can return to your normal lock settings after the build is done.

Select your iPhone from the top of the device list near Loop's window's upper left area, and then press the triangle "build" button similar to how you did your original Loop build.

NOW BE PATIENT. Loop will take a long time to build; between 25-45 minutes depending on your computer. The Loop build process will appear to stall or hang a very long time on one build step in particular. Do not worry. This is normal. One step will take a significant amount of time relative to all the other steps. Once that long step is done, the rest will fly by fairly quickly.

At the end of all the steps, you will either get a Build Succeeded or Build Failed message.

Step 5: Resolve Build Errors

If you get any red build errors or a "Loop Build Failed" message, please check this section for fixes.