Real-time messaging API definition
Real-time messaging (RTM) or Real-Time Communication (RTC) enables the immediate exchange of messages with minimal latency, ensuring rapid data transfer and response.
A real-time messaging API enables instant data exchange between devices or applications. It supports low-latency, bidirectional communication via HTTP/2 (with SSE), WebSockets, or MQTT ensuring efficient, scalable, and reliable delivery for chat, IoT, gaming, or live updates.
It often uses low-latency communication protocols, maintaining a continuous connection between client and server. This setup is essential in applications where quick feedback is critical. RTM systems handle high-frequency, low-size message streams and require efficient connection management, network routing, queuing, and delivery mechanisms to sustain high performance under load. A messaging API facilitates these interactions, providing the tools to implement real-time communication in various applications and tech stacks.
Types of real time messages
Real-time messages can vary based on their purpose, content, and delivery and response time requirements:
- Chat Messages: Text-based messages exchanged in real time, commonly seen in live chat applications, support systems, and social media. These require low latency and can include emojis, images, and videos.
- Notifications and Alerts: Immediate alerts sent to users or systems, such as breaking news updates, push, IoT device alerts, or critical system notifications. These need to be timely and reliable, especially in cases of emergency.
- Command and Control Messages: Real-time instructions sent to devices or applications to execute a specific action, such as controlling industrial devices, financial operations, sending game commands, or adjusting video quality during streaming.
- Data Streams: Continuous data sent in real time, often in high volumes, like stock ticker price updates, GPS data, telemetry or sensor readings in IoT systems. These streams require constant data transmission with minimal delay.
- Multimedia Messages: Real-time transmission of audio, video, or images in applications such as video calls, live streaming, or collaborative video editing. These messages are bandwidth-intensive and require high synchronization for a seamless experience.
How does real-time messaging work?
Real-time messaging is a highly versatile technology. This capability arises from two major factors:
Data is sent using flexible and resilient messaging patterns like publish/subscribe.
Messages themselves are packaged using common formats like JSON.
Additionally, APIs play a crucial role in real-time messaging by providing the necessary interface for developers to integrate these systems into applications. Messaging APIs abstract the complexity of underlying protocols and enable easy implementation of real-time messaging, allowing applications to send and receive messages efficiently, in real-time, without delays. PubNub APIs often support functionalities like event-driven interactions, reliable delivery (message guarantee), user presence detection, message serialization and more.
Fast and resilient messaging with publish/subscribe
Real-time messaging on the web typically involves a system in which data is streamed or pushed to users, applications, or devices with a low-latency, real-time delivery mechanism. PubNub, for example, implements a publish/subscribe (pub/sub) paradigm.
In pub/sub systems, data is published over a channel in the form of messages. Any connected device subscribed to that same channel will rapidly receive those messages as they’re published.
Package message data for easy consumption with JSON
Messages themselves are structured using a common and easily-read data format. PubNub uses JavaScript Object Notation (JSON). This means that messages can be unpacked and used by any recipient, be it a web, desktop, or mobile app, and without regard to the type of device that originally published the message.
Structuring and using real-time messages infrastructure
How a message is actually used across systems, servers, devices and platforms depends on the needs of the application. A chat app, for example, needs to display the messages that users send to one another, along with additional information like the name of each sender. Following this example, the original JSON payload could contain:
The name of the user that sent the chat
The chat message itself.
The time at which the message was sent.
Based on these contents and the channel on which the message was sent, a subscribed chat app would then be able to:
Populate the message body and sender name.
Find and display the sender’s profile picture based on the sender name.
Show the time at which the message was sent.
Display the completed chat message in the appropriate chat room.
With PubNub account, developers can integrate and customize the structure of communication channels and messages free for 14 days.
Real-time messaging vs webhooks
Real-time messaging can be compared to webhooks, which push updates from an app to external URLs as events occur. Webhooks can invoke third-party services or trigger server actions in response to user activity. Still, they are limited to specific endpoints and aren't ideal for scenarios requiring communication among many participants, like chat.
In contrast, real-time messaging like PubNub supports sending large volumes of messages to unlimited participants. The pub/sub model decouples sending and receiving messages, allowing publishers to send without specifying recipients. This flexibility makes PubNub well-suited for various use cases where defining message recipients in advance is impractical.
How can I implement real-time messaging in my application?
Real-time apps can be built from scratch or use existing services, depending on your app’s needs, timeline, and team size.
Leverage web messaging protocols to build from scratch
On a basic level, real-time messaging patterns are enabled by web protocols that let devices freely stream packets of data to one another without waiting for either party to explicitly request that information.
XMPP, WebSockets, and HTTP Long Polling are all good examples of real-time messaging protocols that support high customizability and extensibility, and that can serve as the foundation for a real-time application.
While open-source frameworks exist in many programming languages to support and use these messaging protocols, actually leveraging them as part of your tech stack means handling a much longer list of challenges, including:
- Provisioning and hosting servers
- Ensuring low latency for all users
- Managing user connectivity, especially for mobile users that may be traversing networks
- Designing the data structures for users, messages, and channels to work together flawlessly
- Running and spinning up VMs as your service scales
- Load balancers
- Shared databases
- Replication and POPs
- Maintaining all of this into perpetuity
Building from scratch is possible but demands significant time, effort, and resources, diverting focus from core development. Most teams adding real-time features need a solution that avoids designing and maintaining custom infrastructure.
Accelerate development with a real-time messaging API
A far better option for most teams will be to use a hosted, real time messaging API-based service that has already solved the major networking challenges across web, iOS, Android, and more. This drastically simplifies the development and deployment of new features.
An API-based service like PubNub brings all the power and flexibility of real-time messaging to your team with code-based tools. These let you build real-time functionality without worrying about infrastructure.
Hosted services like PubNub handle speed, scale, and connection management, freeing your team to focus on features.
Choosing a real-time messaging API
Any team looking to integrate real-time communication into their app via an API has many services to choose from. While each may appear to cover the same fundamental needs at a glance, evaluating a service in-depth can be a challenge. As you compare solutions, ask yourself questions like:
- Is the API easy to implement?
- Will this API let us easily add new features?
- Does this API work seamlessly with the tools and technologies I already have?
- Can this service deliver a reliably fast experience for my users?
- Can this service support my traffic as I scale?
PubNub’s real-time communication platform offers easy-to-understand methods that let teams of all sizes leverage our globally distributed, scalable, low-latency network. Additionally, the flexible design of our APIs mean that any real-time feature can be built on PubNub, and our vast catalog of third-party integrations lets your team connect to the services they already love to use.
Real-time messaging SDK
A great chat SDK ensures compatibility with your platform and language, supporting seamless deployment and future scalability. It should provide all API features, enabling real-time chat for web, mobile, IoT, or games using modern SDKs like JavaScript, React Native, Flutter, and more.
PubNub’s Chat SDK offers reliable messaging infrastructure and backend tools for building rich, engaging in-app chat across any platform, empowering you to focus on innovation and user experience.
Check PubNub Chat SDK documentation
For developing web apps, a service must offer Javascript and React SDKs.
For mobile apps, an API should offer:
- React, or Dart + Flutter for hybrid development.
- Android Java and Kotlin (Android), or Swift and Objective-C (iOS), for native mobile apps.
- C# Unity for mobile games.
Finally, for server-side development, look for SDKs for Python, Java, C, Go, and node.js.
In the ideal case, a real-time API simply never makes you choose. PubNub offers the SDK for your platform, whether you’re developing for web, mobile, desktop, or IoT. PubNub will work anywhere, using the most modern technologies available.
