Disclaimer: I am a consultant at Amazon Web Services, and this is my personal blog. The opinions expressed here are solely mine and do not reflect the views of Amazon Web Services (AWS). Any statements made should not be considered official endorsements or statements by AWS.
Recently I stuck in a situation where I wanted to export variable groups from my VSTS account but there was no such option to export variable group. That time I came to know that VSTS has also exposed its API. After that, I just wrote a PowerShell to download all variable groups into a JSON file by calling its API.