Stateless Oauth callback service which allows developers to obtain tokens for VSTS operations.
note: invaluable resource by howlowck which informs many of the "azure-isms" in the app such as specifying the start script (general good practice) and engines field (not so common practice :P)
This service is hosted and available for use at https://stateless-vsts-oauth.azurewebsites.net free of charge. There are no guaruntees made for service availability, functionality, security, performance, or otherwise. If this caveat does not meet your needs, the source is available for use with your own OAuth application and cloud service (or even bare metal, if you so choose) as it was designed for such "lift and shift" cases. The app is configured for Azure Continuous Deployment from the master branch of this repository.
If you're looking for a solution to seamlessly handle authentication for your NPM feeds in VSTS, check out better-vsts-npm-auth.