Virtual machines

On, we have macOS and Linux virtual machines hosted for your builds. You can select from multiple stacks, each with its own list of preinstalled tool versions. Read more about available stacks and stack prepare types in the Available Stacks docs.

The user account that is used for the buils is configured to have passwordless sudo enabled. This way you are able to install all the extra things you need for your builds and for other automation. If a tool is not preinstalled on your Stack of choice, you can install it yourself - see the Install Any Additional Tool guide.


Every build runs in its own virtual machine and the virtual machine is rolled back to a saved state, the “base box” state, after the build is finished. This way your builds are always protected by changes made by others and by your previous builds and you can use a stable environment to define your build workflow, since no state persists between builds.

For more information about build and code security, see the Code security guide.

Whitelisting build machine IPs

Our stacks are behind a set of static public IPs: this means you can whitelist these addresses if necessary. For example, if your security policy only allows a limited set of IP addresses to communicate with your servers.

For the Android & Docker stacks:

For the Xcode and the Visual Studio for Mac stacks:

IP subnet

Please note that the last entry in the list of Xcode stacks is an IP subnet. The entire subnet has to be whitelisted in order to be able to guarantee a seamless build experience!


You can find the macOS base box setup guide and automation scripts we use for building our macOS virtual machine base boxes in our OS X Box Bootstrap repository. The repository includes every script we use for preparing these base virtual machine images.

For our Linux machines, check out the Bitrise Base Docker Image’s repository.

System reports

You can always check our current configurations in the system reports folder of our main repository, to see what tools and which versions are preinstalled. These reports have been generated by the scripts, linked in the first lines of the report.

The repositories used for our virtual machine preparation are open source, and pull requests are welcome. If you’d like to have a tool pre-installed in our machines, feel free to add your changes and they will be included in the related Stack(s) the next time the Stack is updated.

Virtual machine updates

Updates are always announced in the #changelog category of and can be seen on your Bitrise Dashboard. We will also send you a Platform Updates notification about significant changes, unless you disable this feature under your account settings page.

Stack updates

In general we do stack updates once a week, during the weekends.

Minor patches might be applied during the week in case we detect an issue with the current virtual machine environment. These patches do not change any pre-installed tool version, unless it’s really necessary.

We test every stack change as much as we can before it is released to avoid any changes / updates during the week.

iOS Simulator version & SDK support

All the iOS Simulator versions (which can be installed through Xcode, Preferences, Components) are installed and available.