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ArmourDeploy is a swift app developed by ArmourPeak. Invoked from the command-line, it lets Mac admins easily deploy a macOS installer with a single command. If you're a Mac Admin, then you're most likely familiar with Apple's 'startosinstall' tool located inside the macOS ArmourDeploy is part wrapper for 'startosinstall', part downloader for "Install", and all awesome.


ArmourDeploy provides 'Erase All Contents and Settings' functionality for macOS, as well as saving time by maintaining a cached copy of the latest macOS installer on each Mac in the fleet. There is no need for an admin to package and host a macOS installer. The latest build of macOS, compatible with the current running hardware, is downloaded from Apple's servers whenever it is needed. Use your RMM or create a LaunchDaemon to run ArmourDeploy on a regular schedule to ensure your managed Macs have the most up-to-date build of macOS cached on every system. Specify which OS will be cached, including multiple OS versions. Keep a copy of Mojave cached for maintaining Mojave, while also caching the latest Catalina release for providing OS upgrades to Apple's newest Operating System.


What if we choose not to cache a copy of the macOS installer on every Mac? No problem! ArmourDeploy will combine all its features into one continuous workflow, allowing for "on-demand" macOS Installer download and execution of 'startosinstall' as a a single-click operation. ArmourDeploy will display a window for providing progress.

macOS 1-click erase

User interface for Apple's 'startosinstall' tool, displaying progress that the system is preparing. This is a great option when executed from a "Self Service" style tool. Until now, this has been a pain point for admins, since there was no feedback provided to the user that the system is preparing to restart and install (and potentially erase) macOS.

When performing an "erase" operation, an optional captcha can protect the system from accidental erasure. This option can be disabled for fully automated, unattended erase and install workflows.
Jamf 1-click reinstal macOS

For Macs that do not already have a macOS installer cached on the system, ArmourDeploy will provide a user interface displaying progress while downloading the OS from Apple, assembling the installer app, and executing 'startosinstall', all with a single click.

Example policies in Jamf Pro® Self Service. User-initiated, single-click policies will launch ArmourDeploy and perform OS installations and upgrades, even if the user is not an administrator on the Mac. Scope the "Erase All Content & Settings" policies to Help Desk users, who can login to Self Service and run these policies.

ArmourDeploy floats above all other windows, constantly reminding the user that macOS is about to be installed. There is no menu bar or dock item, which keeps the user from quitting the app. For system erase operations, ArmouDeploy always displays a 'cancel' button. Otherwise, the 'cancel' button is not shown unless the --showcancel flag is provided. If no user is logged into the Mac, the GUI will be suppressed, but all operations will continue in the background. Have a look at the various options listed below for running ArmourDeploy.

USAGE:  ArmourDeploy --action install | ArmourDeploy --action cache ArmourDeploy --action status


REQUIREMENTS: Elevated privileges (sudo). The --erase option requires ArmourDeploy to be run from an APFS formatted volume

COMPATIBILITY: macOS High Sierra, macOS Mojave, macOS Catalina


--action, -a Required

  • install Runs startosinstall and presents a user interface displaying progress for the 'Preparing' phase of the installer prior to the reboot

  • cache Caches the latest available build of macOS (specified by --osname) from Apple that is compatible with this Mac. Schedule runs to ensure the latest available build from Apple is being cached. Returns cached build name if installer is currently cached

  • status returns true or false if an OS specified by --osname is currently cached. Good for checking status from RMM


When --action cache install are used together, a user interface displays overall progress. If macOS is already cached, the cached installer is used if it is the most current, and the behavior is the same as using --action install. If macOS is not already cached, the UI will display progress for downloading macOS components, assembling the components into the .app, and the 'Preparing' phase for startosintall. This option is intended for systems that should run startosinstall, but don't have the convenience of a cached installer present on the system.


--appfolder Leave the macOS installer in /Applications. By default the installer will be moved to our Application Support folder. If left in /Applications, macOS may remove it after use.


--erase Erase All Content And Settings, install a new copy of macOS. Requires --action install --osname name


--noforcequit By default, when using the --erase option, ArmourDeploy will force quit any apps after the 'Preparing' phase, regardless of any unsaved documents, or apps that may prevent logout etc. Use this option to override and prompt to close things safely.


--noverify Supresses the captcha presented when using the --erase option only. Use this for unattended erase workflows. Implied if no user is logged in to perform the challenge.


--osname, -n  Required | Name of the macOS Installer to use (ie. Catalina, Mojave, High Sierra). Required for both --action install and --action cache actions.


--showcancel Show the cancel button in the UI. The cancel button will always be shown during an --erase operation, but is optional for an install/upgrade.


--help, h Display available options




Cache Install macOS - If the latest is already cached, returns cached build number. Replaces a build if not the latest (CLI):


/Library/Application\ Support/com.armourpeak.armourdeploy/ --action cache --osname catalina


Install/Upgrade macOS (GUI):


/Library/Application\ Support/com.armourpeak.armourdeploy/ --action install --osname catalina


Erase all content and settings and install macOS Catalina, suppress the captcha (GUI):


//Library/Application\ Support/com.armourpeak.armourdeploy/ --action install --osname catalina --erase --noverify


Cache and download macOS Catalina if it doesn't exist, erase all content and settings and suppress the captcha (GUI):


/Library/Application\ Support/com.armourpeak.armourdeploy/ --action cache install --osname catalina --erase --noverify



Does ArmourDeploy use Apple’s softwareupdate —fetch-full-installer to download macOS Catalina?


No. Our alpha versions of ArmourDeploy used this feature, and the code base still exists for possible future use, but there were a few reasons we shelved this.


 - softwareupdate command launches the “Install macOS” when it finishes downloading. For keeping a cached version “hidden away”, we did not want the app to launch. We built a ‘watcher’ that kills the installer app when it launches, but the app can still become visible for a moment before the ‘watcher’ would kill it. The installer will also be inserted in the “Recent Items” of a user’s Dock

- We wanted to support Mojave and High Sierra for our clients


Can I remove or replace the ArmourPeak logo?


If you would like a “white label” copy of ArmourDeploy for use in your organization or MSP, please reach out to

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