WSO2 3 min

API Custom Properties for better API Governance

APIs are an essential technical aspect to enhance the values of the businesses and the digital transformation journey.

Dinusha Dissanayake
api management

APIs are an essential technical aspect to enhance the values of the businesses and the digital transformation journey. The WSO2 API Manager is an all-in-one API management product which helps to govern the full API lifecycle of an API with a broad set of features.

The APIs let businesses extend their capabilities to interested parties. With the expansion and growth of a business, the number of available APIs can rapidly grow with an increasing amount of use cases requested from within the company.  With APIs playing a key role in the digital transformation journey, it is crucial to have good API governance and management to take the maximum benefits out of the APIs.

APIs consist of a set of pre-defined standard properties such as API name, version and context which can be helpful to identify the APIs’ characteristics. Next to these properties, the API creators and publishers are able to add additional key-value pairs to the APIs. These additional properties are called “API Custom properties”.

This article covers a basic overview of API custom properties and how this feature helps to improve API governance and management.

The API properties are a key value pair. But they should be;

  • Unique
  • No white spaces
  • Case sensitive
  • Based on non-reserved keywords

Why are the API custom properties important?

  • Searchability of the APIs is improved
  • API custom properties can be selectively displayed in the Developer portal
  • Ability to alter API management policies of an API based on custom properties

API Properties can be added to an API using the following two methods;

  • Using the API Manager publisher portal UI, more information on the WSO2 docs.()
  • Using the API Manger publisher product REST APIs, more information on the WSO2 docs.

When you have several APIs, you would need to filter them or search through them quickly in the developer portal or the publisher portal. But it can be difficult to identify an API or a set of APIs with a growing number of APIs in your business. API custom properties help you to achieve a better search experience.

You can simply enter the API property key value pair in the search bar, and it would only list down the APIs which belong to the given API properties, resulting in a better user experience and API governance.

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Searched for authentication:flow1

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Searched for authentication:flow2

Selectively display API Properties in developer portal

Having the option to display API custom properties in Developer portal allows your API creators and publishers to let the API consumers see only a predefined set of properties. As shown in the below image, you can opt for the API property to be shown in developer portal by simply clicking on the “Show in devportal” check box.

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If the APIs’ custom properties are set to be visible in the developer portal, you can search for APIs based on those properties like in the publisher portal.

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API Management policy altering

WSO2 API Manager applies API management policies using the “handlers concept” where each of the API policies such as authentication throttling has its own handler. If a customization needs to be done, a custom handler can be written and configured to be applied to the APIs.

Handler engaging logic can be modified such that the specific handlers will be available for APIs based on their custom properties.

For example, if you have two environments and with two different custom authentication flows, you can easily use API custom properties to engage the relevant environment specific custom authentication handler for an API.


API custom properties are unique key value pairs belonging to an API which provides an advantage in API governance.

They can be added to an API using both the WSO2 API Manager Publisher REST API and Publisher portal UI. While the API custom properties help to improve the user experience of API search for both publisher and consumers, they can also be selectively shown to the consumers. Additionally, API management policies can be selectively applied to APIs using API custom properties.

API governance and management is a key factor in the digital transformation journey. To know more about the capabilities and to be aware of the digital transformation journey, please get in touch with our talented team of experts at Yenlo.

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