Support for editing and hosting Open API 2.0 (Swagger) metadata in Azure Functions is now in preview. API authoring is a popular application of Functions, and Swagger metadata allows a whole network of Swagger-compliant software to easily integrate with those APIs.
These features integrate with the existing Azure App Service API definition support. So you can consume your API on a variety of first-party services, including PowerApps, Flow, and Logic Apps. You can also generate SDKs for your API in Visual Studio.
Read more in our team's blog post.