What are the different types of API integrations?

Different Types of API Integrations

When you're building a modern application, connecting it to external services is usually part of the job. But not all connections work the same way. The type of API integration you choose depends on how your data needs to flow, how quickly things need to happen, and what kind of complexity you're comfortable managing.

This article focuses on all these different types of integrations, as well as their use cases, so you can better understand what works for your application.

TL;DR

• Request-response integrations work like a conversation where you ask a question and wait for an answer
• Webhooks let external services notify your app when something happens, instead of constantly checking for updates
• Batch integrations move data in scheduled chunks rather than instantly, which is great for reports and bulk operations
• Streaming integrations provide continuous data flow for things that need to happen in real time
• Bidirectional sync keeps two systems in harmony by updating both whenever changes occur
• Composite integrations pull information from multiple sources to create a complete picture
• Authentication methods vary by integration type and determine how you verify access

Request-Response Integrations

Request-response integrations are the most common pattern you’ll encounter. Your application sends a request to an API and waits for the answer. For example, when someone fills out a contact form on your website, your app sends that information to an API to process it. It then sends a confirmation once the operation is complete.

This pattern is straightforward and easy to grasp. The main downside, though, is the fact that your application has to wait for the server to finish its work before moving forward, which can impact user experience if response times are slow.

Webhook Integrations

Rather than having your application constantly poll an API to check for changes, webhooks enable event-driven communication. This means that the external service lets you know by sending notifications to your application whenever specific events occur.

Let's say you're running an online store. When a customer completes a payment, the payment processor automatically sends a webhook to your application containing the transaction details. This approach is much more efficient than repeatedly asking for updates, but it does mean your application needs a public endpoint where these notifications can arrive.

Batch Integrations

Sometimes you don't need information instantly, so real-time data isn’t necessary. In this case, batch integrations offer a good and efficient alternative. These integrations handle data in scheduled batches instead of processing individual requests as they occur. This approach is commonly used for data synchronization, generating reports, and bulk operations.

For instance, your application might send the day’s orders to your accounting system every night, or pull product updates from a supplier once a week. While this creates some delay between systems, it significantly reduces the number of individual API calls you're making, which can save both resources and costs.

Streaming Integrations

On the other end of the spectrum, streaming integrations provide a constant flow of data. This is essential for applications where timing really matters, like social media feeds, stock market dashboards, or networks of IoT sensors sending continuous readings.

Instead of the usual request-response cycle, with streaming integrations, data just keeps flowing. This enables real-time dashboards, live updates, and the ability to react to events as they're happening. The integration of API streaming technology is crucial for applications where data must be as fresh as possible.

Bidirectional Sync

When two systems need to maintain consistent data, bidirectional sync is the perfect solution as it automatically propagates changes in both directions. Changes in System A automatically appear in System B, and vice versa. This type of synchronization is what keeps your calendar synchronized across devices, your CRM updated when you send emails, and team collaboration tools working smoothly.

Bidirectional sync comes with its own challenge, which has to do with conflict resolution. When the same data is modified in both systems at the same time, your API integration needs a clear strategy to handle the conflict, whether that's prioritizing one change, merging both updates, or flagging the discrepancy for manual review.

Composite Integrations

Many applications often need information from multiple sources for some functionality to work well. This can be done through composite integrations, which coordinate several API calls and combine the results into a unified response.

When building a user profile page, for example, you might pull authentication details from one service, order history from another, and personalized recommendations from a machine learning API. Each piece comes from a different source, but your application brings them together into one cohesive view. This requires orchestration logic to manage multiple requests and merge everything smoothly.

Authentication in API Integrations

Different integration approaches require different authentication methods. API Keys are the simplest option, where each request includes a secret key for identification. OAuth 2.0 takes a different approach, allowing secure access without having users share any passwords. This is what you're using when you log into an app with your Google or Facebook account.

JWT (JSON Web Tokens) packages authentication information into tokens that can be verified without checking a database every time. This makes them popular for systems that need to scale efficiently while maintaining security, as the token itself contains the necessary verification data.

Choosing What Works for You

The right API to API integration approach depends on what you're building. Applications that need real-time data usually benefit from streaming or webhooks. Bulk data operations work better with batch processing. Systems that need to stay synchronized usually rely on bidirectional sync. And when you need to combine information from multiple sources, composite integrations help you orchestrate everything.

Understanding these patterns helps you make better architectural decisions early on, which will save you from headaches later. Each approach has its place, and sometimes you'll use several types within the same application, depending on what you need each connection to accomplish.

Learn all about API integrations and more with our *comprehensive guide on tools and integrations for modern web development.*