Known issues:

ZAT doesn't run in Windows

Problem: ZAT is a Ruby gem that requires Ruby 2.1 or later to run. However, the Windows installer for Ruby 2.4 and later has a dependency issue that prevents ZAT from running in Windows.

Solution: Install and use Ruby 2.3, or consider using Ubuntu for Windows 10 as your development environment. To install Ubuntu, see Setting up a Bash shell in Windows 10.

App content doesn't load when ZAT server is running

After starting the ZAT server and appending ?zat=true to the Zendesk product interface URL, your app may be blank. The browser is blocking the content from the local zat server because it considers it mixed content.

Note: Firefox and Chrome doesn't block app content, but Safari does. Safari doesn't have an option to disable blocking. As a result, you must use Chrome or Firefox to work with the local zat server.

"Failed to build gem native extension" error in Mac OS X or Linux


Installing ZAT on Mac OS X may fail with the error shown below:

Building native extensions.  This could take a while...ERROR:  Error installing zendesk_apps_tools:ERROR: Failed to build gem native extension.

Possible causes:

  • C compiler is not installed on your Mac. To fix this issue, download and install Xcode, and then install the Xcode command line tools. For information on installing Xcode command line tools, see this guide on After installing Xcode, try installing ZAT again.
  • Thin gem is not installed on your Mac. To install, run the following command in your command-line editor:

    gem install thin -v 1.7.2 -- --with-cflags="-Wno-error=implicit-function-declaration".

    The zendesk_apps_tools gem has a dependency on thin version 1.7.2. Without specifying a version, the later version of thin will compile by default.

You can also use a beta version of the Zendesk Command Line (ZCLI) to build and deploy Zendesk apps. See Using Zendesk Command Line for more information.


Install rake separately with $ gem install rake, then update ZAT with $ gem install zendesk_apps_tool.

"Failed to build gem native extension" error in Windows

Your system environment might be not have all the tools necessary to build and use native Ruby gems. You can install an add-on called DevKit to get these tools. Download the DevKit from the Downloads page on the RubyInstaller website. See Which Development Kit? on the page.

Validate not working in Windows

If you're a Windows user and the ZAT validate function gives you an error, ZAT might be having trouble finding a JavaScript runtime on your system. The best solution we’ve found is to install Node.js. You can download Node.js at

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