How to use SaaS APIs successfully in 2025

Whether you’re looking to integrate your organization's SaaS applications or connect your customers’ with your product, you’ll need to use the applications’ APIs.

We’ll help you do so successfully by breaking down impactful examples of SaaS integrations. But first, let’s align on the definition of SaaS APIs.

What are SaaS APIs?

SaaS APIs consist of endpoints that let you access certain types of data and functionality in SaaS applications. 

They include the following elements:

• Rate limits: determine how many calls a user can make to an endpoint over a predefined period of time

• Authentication: verifies the user’s identity (e.g., OAuth 2.0 tokens) before performing the request

• Pagination: determines how the data is returned and how subsequent requests should be structured

• Response codes: explain whether a request was successful or not—and if not, why 

For example, Sendoso, a gifting platform, supports the following for their API endpoints:

• Rate limits: Sendoso limits requests to 10 per second for every client (after that, it begins to throttle or temporarily block requests until the rate limit window expires)

• Authentication: Sendoso uses Oauth 2.0. This requires registering the app to get a unique client ID and secret, and then using those credentials to get an access token from their OAuth endpoint. Once you have that token, you can use it in the Authorization header for any request you make to Sendoso’s endpoints

• Pagination: You can use page and page_size query parameters to gather fewer resources per request. This is known as offset-based pagination

• Response codes: Sendoso uses standard API response codes, like 200 OK, 400 Bad Request, 429 Too Many Requests, and so on

It’s worth keeping in mind that API providers approach these areas differently, so you’ll need to read through their documentation thoroughly before building to their endpoints.

Note: SaaS API management is often used interchangeably with SaaS APIs, but it’s broader in scope. The former refers to the end-to-end process of handling API requests, from authenticating requests to analyzing API usage to troubleshooting and resolving errors.

Examples of SaaS API integrations

You can build internal SaaS API integrations, or integrations that work across the applications your organization uses internally, or product-based SaaS API integrations, which work between your product and your customers’ apps.

Internal SaaS API integrations

Here are just a few examples of internal integrations.

Connect your CRM with your ERP system to send invoices on time

To help your finance team build and deliver invoices soon after a prospect converts into a client, you can connect your accounting solution with your CRM and build a flow where once an opportunity is marked as closed-won in the CRM, their account automatically gets created in the accounting solution. 

The newly-created account can include all of the relevant information from the deal, enabling finance to create the invoice quickly, independently, and without issues.

Integrate your ticketing system with your file storage app to automatically store important documents

As your customer support and success teams work through issues with clients, they’ll often receive documents worth preserving—whether it’s screenshots of bugs, log files showing errors, or other supporting materials.

To help them store these documents effectively and with ease, you can build an integration where specific types of documents uploaded to your ticketing app are automatically routed to the appropriate folder in your file storage system.

Customer-facing SaaS API integrations

Here are some real-world examples of customer-facing integrations.

Ramp’s integrations with HRIS solutions 

Ramp, a leading financial operations platform, offers HRIS integrations to help customers add users to and remove them from the platform more easily.

More specifically, once a user is added in the integrated HRIS, a Ramp admin can invite them to the platform with a few clicks. That user would eventually be auto-provisioned corporate cards based on their data in Ramp and the rules their employer sets.

Conversely, if a user is removed or marked as terminated in the connected HRIS, the Ramp admin will get notified and can deactivate that employee’s account—including their corporate cards—with a few clicks.

Juicebox integrates with ATSs

Juicebox, which offers an AI-powered solution for sourcing and recruiting talent, uses ATS integrations to surface open roles within their UI. Juicebox users can even click on one of the listed roles to automatically start generating candidates.

Once a user starts to nurture candidates in Juicebox, they can also add them to the integrated ATS in a matter of clicks.

Kertos integrates with ticketing apps

Kertos, a compliance automation platform, offers ticketing integrations to help customers identify and work on tasks that would them comply with critical security frameworks, like GDPR.

For example, once a task is created in Kertos, it’s automatically created in the customer’s integrated ticketing solution with all of the pertinent details (name of the ticket, a description, the assignees, the due date, etc.). The tickets also get synced bidirectionally. That way, as customers work on the ticket in the ticketing system, the task gets updated accordingly in Kertos.

Benefits of using SaaS APIs

Using SaaS APIs, clearly, offers several benefits. These also vary depending on whether you’re implementing internal or customer-facing integrations. 

Here are just some of the benefits:

• Offers secure connections. By enforcing authentication protocols, SaaS tools’ sensitive data can be kept safe and secure over time

• Provides fast and flexible sync frequencies. You can sync data as frequently as every minute or as infrequently as every 24 hours—enabling consumers to use APIs efficiently while helping providers manage request volumes

• Supports countless use cases. As you saw from our integration examples, SaaS APIs can support seemingly endless workflows across industries, regions and company sizes. As more and more SaaS companies get built and offer APIs, the supported use cases will only increase

• Monetization opportunities: SaaS API providers can charge for API consumption, providing them with a sustinable and potentially lucrative revenue stream. All the while, companies that offer product integrations via SaaS APIs can charge them as add-ons to existing subscripitions or include them in high tier plans, allowing them to upsell customers more easily

• Lets you scale via unified APIs. A unified API solution lets you integrate with hundreds of SaaS applications through a single, aggregated API

This lets you meet all of your customers’ integration needs quickly and it enables your sellers to close more deals—as integrations are no longer a blocker.

In addition, with Merge, the leading unified API solution, you can:

• Empower your customer-facing teams to observe and troubleshoot integration issues via Merge’s searchable logs, automated issue detection, and holistic dashboard

• Sync any custom fields through features like Field Mapping

• Get guidance on taking your integrations to market—whether that’s deciding how they’re priced, marketed, or supported

‍Learn more about Merge by scheduling a demo with one of our integration experts.