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What are Evented APIs?

In a world driven by data, it is becoming increasingly important for businesses to gather and analyse vast amounts of data in real time. By doing this, they are not only able to offer their customers a better customer journey but are also able to make better data-driven decisions. As a result, they can be more efficient, productive, and profitable.

Unfortunately, most of the APIs today are synchronous APIs that are inefficient and simply not capable of delivering the real-time data integration and insights that would allow businesses to capitalise on the benefits mentioned above.

Enter evented APIs. Based on events rather than requests, they give businesses the insights they need much faster and provide consumers with the information they need when they need it.

What are Evented APIs?

To understand what evented APIs are, we must first understand what an event-driven architecture is. At their core, event-driven architectures use events to initiate communications between multiple decoupled, integrated applications.

Conversely, synchronous APIs rely on the client to initiate the communication. During this communication, they use a request-response pattern where the client sends a request to the backend and the backend then returns a response.

The drawback with this approach is that these API calls happen one at a time. Also, every call blocks the progress of the process until it is complete. As a result, developers often use polling to continuously query an API if their application needs updates regularly.

Obviously, this process is inefficient at best and far less reactive compared to interactions driven by events. Also, it gets more inefficient as the volume of data and the need for real-time data increases.

So, what is an evented API? Well, we can think of an evented API as the fabric that binds and integrates all the applications in an event-driven architecture. In other words, evented APIs integrate many applications and services in the infrastructure. That is why they are also referred to as event-driven APIs.

In these architectures, event emitters, event consumers, and event channels drive interactions. Here, events occur any time when there is a change of state and result in the API pushing new data to the consumer.

Why are event-driven architectures becoming significant in modern infrastructures?

Nowadays, consumers expect more interactive experiences and they demand information without taking any specific action to get it. In other words, they want to know about things as they happen. Likewise, as many businesses increase their digital transformation efforts, they have an increased focus on agility and scalability.

Here, event-driven architectures offer several benefits:

  • Real-time data processing. In a competitive market, it's vital that businesses ingest and analyse vast amounts of data quickly. It allows them to make data-driven decisions faster, improve their processes, and serve their customers better.

  • Reduces costs. Typically, businesses would implement batch processing systems that keep collecting data and process it periodically. For businesses that need data more regularly, developers would, as mentioned earlier, use polling. Event-driven architectures now allow these businesses to reduce the infrastructure and resource costs needed to periodically process substantial amounts of data or for continuous polling. Ultimately, this reduces operating costs, while increasing efficiency and productivity.

  • Scalability. Event-driven architectures have the ability to scale as the number of applications that generate events increase. Also, compared to monolithic, legacy systems, the decoupled nature of event-driven architecture prevents system failures when one of the applications fail.

  • Improved customer experience. By giving customers the information they need when they need it, the customer experience is greatly improved. Another aspect that allows businesses to achieve this, is that they can identify issues and trends as they emerge and respond better to them.

Common business applications and operational areas that benefit from Evented APIs

Considering the benefits mentioned above, businesses would typically use event-driven APIs when applications:

  • Need to push information from the server to the client instead of the client requesting it.
  • Must provide users with a two-way communication channel.
  • Require a large number of continuous interactions between the client and the server which impedes scalability when synchronous APIs are used.
  • Need to monitor system-wide events.

With that in mind, some of the common business applications and operational areas that benefit from evented APIs include:

  • Customer services
  • Business dashboards
  • Personalization
  • Price optimisation
  • Messaging
  • Collaboration

What problems do Evented APIs solve?

Considering the above, it is clear that event-driven architectures have the ability to not only allow businesses to improve the customer journey but also enable them to be more efficient and productive. It is not all good news, though, and some challenges surface.

These challenges mainly arise from the fact that event-driven architectures are quite novel and, as such, have not yet caught up when it comes to the solutions for API management. For example:

  • Event-driven architectures have only recently begun to have specifications.
  • There are, unlike RESTful APIs, no catalogues yet for event-driven APIs.
  • It could be challenging to work with event-driven architectures because developers need to work with multiple protocols.
  • No unit tests and test-driven software approaches have been developed for event-driven architectures.

Evented APIs were designed to solve many of these challenges and bring the level of governance that RESTful services have, to event-driven architectures. This is because they offer specifications, testability, security, and a standardised developer experience.

Our recommendations

When businesses consider implementing event-driven architectures to enable real-time data processing that will allow them to be more pro ductive, efficient, and profitable, there are some things they need to consider. In other words, for the implementation to be successful, it needs to be carefully planned.

During the planning and implementation, we recommend that:

  • The proposed implementation supports the needs and requirements of the business. If not, the complexity and effort may not be worth the value that businesses could gain from implementing it.
  • The implementation supports advanced analytics that relies on event processing. This allows businesses to gain insights from their data and find value in it.
  • The implementation uses high performance and highly scalable systems and autonomous components that provide the scalability benefits referred to above.
  • Businesses eliminate point to point integrations that are not only complex to implement but also challenging to maintain.

To find out more about implementing an event-driven architecture and evented APIs, give us a call, or email us at

Other useful links:

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