Creating an API (definitions)

Azure API Management is an API-Gateway service on Microsoft’s Azure Platform. You can use API Management to provide a Gateway to any service residing on-premise, in a container or cloud (back-end services). It can help you securely expose your APIs to third parties, partners or internally.

Any service (back-end) you have can be hooked into API Management and have in- and outbound traffic managed through configuration and policies. Within an API Management instance, you can create an ‘API’ or API definition representing the operations of your services.

The API (definition) contains a reference to operations of your services, and you configure them as you have control over URL mapping, query and path parameters, request and response content, and operation response caching. Furthermore, you can implement rate limit, quotas, and IP restriction policies on each operation or at the API level. In short, the API (definition) is a proxy or gateway into your back-end services.

Through the Azure Portal, you can access an API management instance and create an API (definition). Under APIs in the left pane of an API Management instance, you will find APIs option allowing you to add a new API.

As the picture above shows, you have several options to create an API (definition) ranging from blank to a Function App. The option you choose will depend on how you want to define your API (back-end service) representation in API Management. Regardless of which option you choose, you will have to define the display name, name, scheme and other details as shown below.

The tip here is that when creating an API (definition), you have to consider first what it is going to represent. Next, as you will read in other tips, on how you will define the operations, do versioning, specify subscriptions, and how to configure and add policies for in- and outbound traffic to your back-end service(s). API (definitions) as you will learn are the cornerstone of API Management.

In the Microsoft docs, you will find how to define APIs:

• Manually (blank API)
• OpenAPI
• SOAP API
• API on an App Service
• Function App
• Logic App
• API on Service Fabric

And lastly, also look into the limitations of several of the above-listed import options described in the Microsoft Docs: API import restrictions and known issues.