Businesses and users increasingly rely on real-time applications — from banking, e-commerce, and streaming to logistics, predictive maintenance, and the Internet of Things (IoT). If you look under the hood, you’ll likely see asynchronous APIs (async APIs) powering your favorite applications. These non-blocking APIs have become ubiquitous across many industries.
We’ve previously discussed the basics of asynchronous APIs. We’ll now look at some real-world use cases for these APIs and the communication protocols they often use.
What are asynchronous APIs?
Async APIs are a category of APIs that includes streaming, message queues, and event logs, as well as APIs that specify async processing. They can run simultaneous non-blocking operations themselves — no added server-side code. In general, you can implement nearly all APIs to support asynchronous operations.
These APIs use various communication protocols, such as Advanced Message Queuing Protocol (AMQP), Message Queuing Telemetry Transport (MQTT), WebSockets, and Server-Sent Events (SSE). These protocols allow APIs to respond to requests or events in real time, which makes them ideal for a wide range of applications.
Real-world use cases for asynchronous APIs
Nearly all industries today require real-time applications, and non-blocking APIs make them possible. These APIs use different communication protocols, each suited for different use cases. Let’s look at some examples of applications that tend to use asynchronous APIs and common methods of communication for real-time data exchange.
Async APIs with AMQP
AMQP, a JPMorgan Chase initiative from 2003, has roots in the finance sector. Other industries have come to leverage this protocol in their apps because of its reliability and scalability:
- Trading platforms — These often use AMQP to perform tasks in real time, such as quoting stock prices, updating exchange rates, and executing stock trades.
- Healthcare platforms — Many developers use AMQP to implement reliable data exchanges for healthcare applications and systems. Use cases include remote patient monitoring and electronic health records (EHR) applications.
- Message brokers — Many applications implement AMQP through message brokers like RabbitMQ and Apache Qpid. The protocol provides a universal language for communication between message brokers and applications, ensuring compatibility across systems.
Async APIs with MQTT
MQTT is commonly used for IoT and machine-to-machine (M2M) use cases because it’s lightweight and designed for sending data to and from devices and networks with limited bandwidth. This protocol is ideal for applications that leverage sensors, such as:
- Smart home automation — You’ll often see MQTT in smart home systems, many of which leverage AI and sensors to regulate various aspects of the home, like temperature, lighting, and air quality.
- Fleet management — Most transport and logistics systems rely on MQTT to transmit real-time data regarding fleet vehicles, such as location, movement, fuel consumption, and diagnostics. Sensors located throughout each vehicle generate this data.
- Healthcare monitoring — MQTT facilitates data exchanges between wearable devices or remote medical equipment and a centralized healthcare monitoring system. Sensors gather the data and MQTT sends that data back to the main system.
Async APIs with WebSockets
Developers often use WebSockets in applications because they enable real-time, bidirectional communication with low latency. Applications that commonly use WebSockets include:
- Online gaming — WebSockets can facilitate real-time interactions among players in massively multiplayer online games (MMOs). They synchronize the game state across the server and clients.
- Live streaming — This communication protocol allows live streaming applications to deliver real-time updates to viewers. For example, sports streaming applications and data delivery services might use WebSockets to provide live scores, game updates, and player statistics.
- Social media — Some social media platforms use WebSockets in instant messaging or push notifications. For example, Instagram and Facebook Messenger push MQTT over WebSockets to send and receive messages.
Async APIs with SSE
SSE facilitates automatic, one-way communication between a server and a client over an HTTP connection. Its advantage is that it eliminates the need for continuous polling by clients. Here are a few examples of apps that leverage SSE:
- Live data visualizations — SSE enables data visualization applications to update massive volumes of data. For example, Shopify moved to an SSE server for its annual Black Friday Cyber Monday (BFCM) map. Developers could create similar live maps by enabling SSE with async APIs.
- Flight tracking — Some flight tracking applications use this communication protocol to provide live updates or notifications to vast numbers of customers simultaneously. Updates can include flight departures, statuses, gate changes, or delays.
- Online shopping platforms — Some e-commerce platforms use a combination of communication protocols, including SSE, to push real-time updates from the server to clients. SSE is great at enabling live inventory updates and price changes.
You’ve probably already noticed that applications can use a combination of communication protocols. For example, the above instant messaging applications push MQTT over WebSockets to send and receive messages. Many collaboration tools use AMQP and SSE for different functions, like live editing updates and messaging.
Asynchronous APIs power a wide range of applications, many built on event-driven architectures (EDAs). In fact, these APIs play an essential role in the real-time functionality of EDAs.
Async APIs: Critical to event-driven architectures
Event-driven architectures typically rely on non-blocking APIs due to their many benefits, including:
- Decoupling — Asynchronous APIs enable EDA components to operate autonomously, making adding, removing, or updating them easier without causing major disruptions throughout the application.
- Responsiveness — With non-blocking APIs, components can process new requests while waiting for others to complete. The EDA can handle concurrent operations and respond to requests in real time, even when an application experiences high traffic.
- Scalability — EDAs with async APIs have more flexible scaling. For example, some components or services may receive far more requests than others. Because they’re autonomous, developers can scale only the ones that need it instead of scaling them all regardless of their individual load.
Asynchronous APIs enable real-time functionality in EDA-driven applications while allowing them to perform well as the user base grows. You’ll rarely find an EDA without non-blocking APIs under the hood.
Create innovative real-time applications with async APIs
The use cases highlighted in this article only scratch the surface of what you can do with async APIs and the communication protocols they enable.
Regardless of your industry, you can create innovative real-time applications that delight users and solve business problems. The only limit to what you can do with these APIs is your imagination!
