Azure Functions, a central part of Microsoft’s serverless offering, provides a lot of functionality to quickly develop and deploy code to your solution. In this blog post, Vidar Kongsli sheds some light on the security related functionality that is offered. He discusses the type of authorization required for calling the function, the generated app keys at function app and function level, and how to authenticate users. By creating app keys for each client that will be calling the function, you get essential API key functionality, and you can programmatically identify the calling client. This blog post is particularly helpful for individuals or organizations that use Azure Functions and want to secure their system.