What is API integration? Here’s what you should know

An overview on API integration

When data can’t move freely between your apps, harmful business consequences emerge. 

Employees will have to navigate between apps just to find the data they’re looking for; they’ll have to perform double data entry constantly; and they’ll have to give up valuable time in performing business-critical tasks. 

You can address these issues head on by investing in API (application programming interface) integration. How does it help? We’ll explain, but let’s start by aligning on what the term means.

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What is an API?

An application programming interface is either (depending on who you ask) a collection of API endpoints or a single API endpoint for a specific application—where each endpoint lets you access data or functionality from that application.

While there are many different types of APIs, the most common is a REST or RESTful API, which provides a specific set of standards and rules for building and calling to APIs. For example, a REST API call needs to use an HTTP protocol and a uniform resource identifier (or URI) to specify where a specific type of resource lives. Moreover,, you’ll need an HTTP verb that defines the request, which can be a GET, POST, PUT, or DELETE request (among others). Once the server validates the request, it provides an easily-readable response, typically in JSON format.

A visual breakdown of a REST API call

To learn more about APIs, including the different types you can use and the benefits they provide, you can read this guide.

Related: How to choose between RPA and API integration

How does API integration work?

It’s the use of an in-house or 3rd-party solution to facilitate communication between applications via their APIs. Once connected, these applications can request and share data between one another seamlessly, effectively eliminating any data silo at your organization.

For example, say you use Salesforce as your CRM and Marketo as your marketing automation platform. Using an API-based integration, you can connect the systems and allow key information to flow between them. Has a sales rep updated a prospect’s status in Salesforce? Those edits can instantly be reflected in Marketo; did a prospect’s lead score change after a Marketo campaign? The corresponding Salesforce account can automatically use the new score—and so on. 

This example is just the tip of the iceberg. We’ll provide more context on how you can apply API integration by covering additional examples next.

API integration examples

Here are some API integration use cases that work across different teams and applications:

Message a Slack channel automatically when a key employee event occurs

Throughout your employees’ journey at your company, they’ll reach various milestones that are worth bringing attention to and recognizing—from getting promoted to reaching a work anniversary. 

To support your team in this effort, you can integrate an HRIS like Workday with a business communications platform like Slack and build a workflow where once a specific object gets updated within the employee’s profile (e.g. job title), a customized message gets sent to a preselected Slack channel (e.g. #employee-announcements).

A screenshot that visualizes the workflow between Slack and Workday

Members of that channel can then go on to congratulate the employee either in the channel or via a direct message.

Related: What is REST API integration?

Create issues for the relevant department in real-time

To help the right team become aware of an issue quickly, you can integrate the tool that one function uses to manage issues (e.g. engineering uses Jira) with another that a separate team relies on (e.g. customer support uses Zendesk). 

From there, you can build a workflow that goes as follows: Once an engineer updates an issue in Jira to denote that customer support needs to resolve it, the workflow gets triggered. The ticket goes on to get created in Zendesk if it doesn’t already exist; once it’s created (or already exists), its fields are updated based on the corresponding information in the Jira issue. 

A screenshot that visualizes the workflow between Jira and Zendesk

Add signed documents to your file storage platform quickly

Whether it’s a fully-executed offer letter or contract with a client, you’ll want to ensure that the completed document is stored securely and in the appropriate location.

To help you do just that, you can integrate your e-signature platform (e.g. DocuSign) with your file sharing and storage solution (e.g. Box); from there, you can implement a workflow where any time a specific type of document gets signed, it’s then added to a predefined folder in your file storage platform.

Related: API integration examples worth leveraging

Why is API integration important?

Here are 7 key benefits of API integrations:

Offers high performance

There are a number of reasons why APIs are a great option for implementing integrations:

  • Can move data in milliseconds or seconds, allowing employees and partners to access data as soon as they need it
  • Provides a security layer with access controls, ensuring that only specific employees have access to certain data points
  • Unaffected by changes to your application’s UI, making them more resilient in the long run than RPA software
  • Purpose-built for integration, and as a result, APIs focus on providing a high level of performance and stability 

Saves employees time

Now that your employees can avoid moving between apps to find the data they need, they’ll save a significant amount of time that they can reallocate towards other, more important, tasks.

Your marketers can spend more time on creating content assets for a given campaign; your sales reps can focus more on building out presentations for key prospects; your colleagues in finance can ideate strategies for improving their compliance and risk management; your employees in HR can hold more important conversations with employees, etc.

Related: Why API management is important

Prevents human errors

No individual is immune to mistakes. If they’re tasked with updating several applications themselves, they’re bound to make errors that lead to big issues down the line. 

For instance, if someone working in Salesforce gives a prospect a higher lead score than what’s shown in Marketo (i.e. the source of truth), a sales rep can be misled into thinking that a prospect is more sales-ready than they really are. This can lead the rep to nurture that prospect in a way that comes off as aggressive—ultimately dissuading the prospect from engaging with your brand any further.

API integration lessens the number of manual tasks your employees perform, thereby lowering the chances of incidents like the one above from taking place.

Improves the employee and customer experience

With employees able to spend more of their time on tactical, thoughtful tasks, versus manual, repetitive ones, they’re more likely to enjoy their work and be more productive. This also benefits customers as, according to the Harvard Business Review, happier employees are more likely to deliver experiences that leave customers happier as well. 

Related: How SaaS integration can deliver value to your organization

Helps you get the most out of your apps

Once your apps include additional data via API integrations, the utility they provide to users only amplifies. Here are just a few examples:

  • You CRM platform can provide a 360-degree view on prospects and clients, empowering sales reps and colleagues in customer-facing roles to manage these key relationships more intelligently
  • Your applicant tracking system can retrieve offer letters sent to candidates and their respective completion statuses, helping recruiters track target candidates and follow up when necessary
  • Your ERP system can display accurate order information and generate invoices instantly, helping your finance team manage vendors effectively
  • Your marketing automation tool can access clients’ product usage data, enabling your marketers to nurture upsell and cross-sell opportunities successfully

Strengthens your relationships with partners

You might partner with 3rd-party organizations to help sell your product or support clients. In either case, API integrations can help strengthen the partnership.

For example, let’s say that you rely on partners to advise and support clients. Let’s also assume that your middleware tool can provide API management capabilities (which isn’t always the case). In this scenario, you can provide APIs that share new clients and provide details around the sale (e.g. the plan they purchased). Your partners can then connect these endpoints with their own internal system(s), allowing them to quickly become aware of the clients they need to reach out to and how they need to support them.

Enhances the product your organization offers

Many popular apps rely on API integrations to deliver value for end-users. You can point to various real-world examples for proof. 

This can be anything from a travel site like Expedia, which uses the APIs of various 3rd-party sites to help its searchers find the best deals on flights, hotel stays, car rentals, etc. to a payment service like Venmo—which uses the APIs of several banking institutions to let users transfer money over to their accounts.

Though your product’s API use cases may not be as obvious as the examples above, you’ll likely identify several opportunities that can improve your end users’ experience.

Related: The top benefits of API integration

How to build an API integration

Once you’ve decided to integrate your apps via their APIs, the next question is how you want to go about doing it. You have a few integration solutions to choose from, with each offering a unique set of pros and cons:

1. Native API integration: When you use an app’s pre-built integration with another app


  • Often provided at a low cost with your subscription
  • Normally supported by the organization that provides them
  • Can cover a variety of use cases across popular apps


  • Your organization likely has specific integration requirements that aren’t met by the native integration
  • The organization’s engineers have competing priorities, which can prevent them from focusing their time and effort on enhancing and fixing their native API integrations
  • It can’t deliver real digital transformation as building integrations doesn’t dramatically change your organization’s core workflows

2. In-house API integration: When your team builds the API integration from the ground up


  • Can be customized to fit the needs of your organization
  • Certain API integrations may be less complex to build


  • Can come at an extremely high cost, as it takes your colleagues with a technical background a significant amount of time to develop and maintain each integration
  • It’s an unscalable solution, as you likely have hundreds of apps that you’d like to integrate
  • It can’t deliver real digital transformation as building integrations doesn’t dramatically change your organization’s core workflows

Related: 5 API integration best practices

3. 3rd-party API integration: When you use a middleware platform to implement the integration


  • Can help you integrate several apps quickly and securely
  • Normally provides support for existing connectors while adding new connectors over time
  • Users can access a single dashboard for monitoring the integrations


  • It requires technical skills, which prevents the team at large from building integrations
  • It can take a long time to get comfortable with the platform and to build integrations at scale
  • It can’t deliver real digital transformation as building integrations doesn’t dramatically change your organization’s core workflows

You’ve likely noticed a common thread across these options: They can’t transform the core operating processes at your organization. What can? Read on to find out.

Related: Everything you need to know about workflow integration

How Workato is different 

Workato, the leader in enterprise automation, allows your team to integrate SaaS apps, on-prem systems, databases, etc. AND build end-to-end automations across core processes without writing a single line of code. 

Want to learn how the low-code/no-code platform can enable your broader team to build integrations effectively and safely? Wondering how enterprise automation can transform your organization’s business processes?

You can uncover the answers to both questions—and more—by speaking with an automation expert.

API integration FAQ

API integration can invite a wide range of questions. In case any of yours haven’t already been answered, we’ll tackle some additional commonly-asked questions below.

What is an API management platform?

It’s a platform that allows you to create and host API endpoints. The endpoint can function in a variety of ways: it can call the API of another application, retrieve data from a database, download a file and look up information in that file, or perform specific business logic.

As you build up your collection of APIs, your colleagues and partners can begin to rely on them when implementing automations and do so without worrying about the applications and data behind the API endpoints. 

What other types of integration exist?

You can also integrate applications at the UI level with RPA software. More specifically, using the software, you can program a software bot to copy the activities a person takes in performing a specific task (e.g. keying in data). In addition, you can integrate applications via file sharing.

While the integration approaches above can be valuable when used in the right scenarios, they come with several drawbacks. As an example, data can’t move in, or near, real-time between applications (instead, data would move from one system to another in minutes, hours, or even days).

What is an API integration platform?

An API integration platform is a middleware tool that allows you to connect applications via their APIs. 

In the real world, middleware tools normally offer more than one means of connecting applications. For example, in addition to providing API-based integration, they would allow you to connect applications via file sharing. Therefore, an API integration platform, according to its narrow definition, rarely exists today.

What are the different types of APIs?

There are 4 types of web APIs (the type(s) you use will ultimately depend on your specific integration and automation use cases):

  • Public APIs (also known as open APIs): an API that any organization or developer can access
  • Partner APIs: an API that only authorized partners can access
  • Internal APIs: an API that the organization only intends to use for connecting internal systems 
  • Composite APIs: when two or more API requests are batched into one API call

How much does it cost to build an API?

Given the time it takes to implement—from researching what, exactly, the API needs to putting a working prototype together to creating the necessary documentation around it—and maintain, it could cost your organization tens of thousands, if not hundreds of thousands, of dollars. Moreover, there’s an opportunity cost to consider: forcing your developers to focus on building and maintaining APIs leaves them without time to work on other core initiatives that only they can take on. 

What is an API systems integrator?

An API systems integrator (also referred to as a systems integrator, or an SI) is any individual or company that helps their clients build and maintain API-based integrations. 

They often favor specific integration tools and have certain areas of expertise. In addition, they can be involved in different stages of an integration project, such as assessing and defining the requirements and then implementing a solution, or simply performing maintenance.

What is the difference between API and integration?

An API is either an endpoint or a collection of endpoints that allow you to access certain data or functionality from an application; all the while, integration is the process of making independently-designed systems communicate with each other.

What are some common API integration patterns?

Some commonly-used patterns include:

  • Data synchronization (either two-way or one-way), which allows data to be consistent across different systems.
An example of mapping fields
 between a CRM and an ITSM tool for  cases
An example of certain fields in a CRM that can be synced with corresponding fields in an ITSM tool
  • Data integration, which involves extracting data from a variety of source systems, transforming it, and then loading it into a data warehouse. From there, data can be sent over to downstream systems, such as BI or analytics tools.
  • B2B integration, which enables an organization to communicate with business partners (e.g. suppliers) in order to manage and complete transactions effectively.

How do you design an API integration strategy?

Similar to designing other types of digital transformation strategies, it involves performing the following steps in sequential order:

A framework for designing an integration and automation strategy
  1. Determine your goals from implementing API integrations (e.g. saving X amount of time per week).
  1. Pinpoint the use cases that can help support these goals (e.g. data synchronization).
  1. Align on the API integration solution’s nonfunctional requirements (e.g. reliability).
  1. Based on the goal set in step 1, you should be able to determine the delivery strategy that makes the most sense. For example, if you’re looking to innovate, you should adopt an API integration platform that offers a low-code/no-code UX (as citizen integrators who understand the associated data, applications, and processes the best can then feel empowered to get involved).
  1. Once your functional and nonfunctional requirements are outlined, you’ll be able to pick out the best platform for your business.

It’s worth noting that your integration strategy isn’t performed once. You’ll need to revisit it frequently (e.g. twice per year) in order to accommodate changes in your company’s overarching goals, technology, market, among other factors.

About the author
Jon Gitlin Content Strategist @ Workato
Jon Gitlin is the Managing Editor of The Connector, where you can get the latest news on Workato and uncover tips, examples, and frameworks for implementing powerful integrations and automations. In his free time, he loves to run outside, watch soccer (er...football) matches, and explore local restaurants.