What tool would you use to create a custom API in Azure?

To create a custom API in Azure, utilizing Azure API Management is the most appropriate choice. Azure API Management provides a complete platform for creating, publishing, securing, and analyzing APIs. It enables developers to create APIs that can serve as a gateway to backend services, which can include functions, web applications, or other services.

Azure API Management allows for various configurations, including defining access policies, handling authentication and authorization, enabling throttling, and generating documentation for the APIs. This creates a robust environment for developers to manage their APIs effectively, ensuring that the APIs are secure and perform well.

While Azure Functions is used to create serverless applications and can certainly host API endpoints, it lacks the complete feature set for managing APIs that Azure API Management provides. Azure Blob Storage is primarily intended for storing unstructured data like files, and Azure Logic Apps is more focused on building workflows to automate business processes, rather than serving as a dedicated API management solution. Thus, Azure API Management is the most fitting option for creating and managing custom APIs.