Color samples showing the types of APIs.

When comparing the types of APIs (application programming interfaces), API architecture types and different API categories are incredibly important. The following article will discuss API architecture and protocol types (REST and SOAP) and three types of API categories (open, internal, and partner).

You don’t necessarily need a lot of technical experience to create and manage APIs. Start a free account with DreamFactory to generate and manage low-code APIs from a user-friendly dashboard.

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Rest APIs (also known as RESTful APIs) appeal to many developers and organizations because of their lightweight, scalable designs. REST, by the way, stands for “Representational State Transfer,” which means that when a client uses the API to request information, the server returns information in a standardized representation. That might sound a bit complex to anyone without a lot of API experience. Just know that the client gets information in a way that the user can understand. For example, if you request information about videos, you might get a list of links to videos.

REST APIs are commonly web APIs that cooperate easily with HTML, the markup language used to structure and link websites. When someone using the internet or World Wide Web wants to search for something on your website or database on your server, they request the information. That request gets submitted to appropriate API endpoints that can communicate with the server and send back the requested information. REST is considered one of the most important API architectural styles.

Features of REST APIs

REST API is one of the most popular types of APIs. Some critical features that make them attractive include:

  • They are stateless, which means they complete one request at a time.
  • They support JSON (Javascript Object Notation) and XML format.
  • They document every request.
  • They have a uniform interface that makes them easier to use.
  • They send software developers error code when something goes wrong. (Users get generic errors, such as 404 when a page doesn’t exist. Developers get more meaningful error messages that contribute to solving problems.)


SOAP is an initialism for “simple object access protocol.” SOAP APIs have diverse uses that benefit web services and networks. Modern SOAP APIs transfer information via HTTP protocol (Hypertext Transfer Protocol), so it’s not surprising that many websites rely on it for client-server communications. Earlier forms of SOAP APIs used SMTP (Simple Mail Transfer Protocol), but that approach has fallen out of favor. You might still find it when using legacy systems.

Features of SOAP APIs

Why would a developer choose SOAP APIs over other types of APIs?

Some essential features of SOAP API include:

  • Heightened security that uses SSL support and WS-Security.
  • Wide bandwidth that doesn’t tend to get “stuck” as easily as some types of APIs.
  • Conforms to ACID (Atomicity, Consistency, Isolation, Durability) compliance, which can also improve security.

SOAP APIs take more time to set up than REST APIs, but they work well for organizations that need to prioritize security and have the resources necessary to manage protocols.

SOAP is considered an API protocol. A big advantage that REST API has over SOAP API is that REST can use the SOAP protocol.

Confused about the differences between the types of APIs? Read “SOAP vs. REST: What’s the Difference” for a deeper understanding.

Open APIs

Open APIs (also called “public APIs”) are the least strict types of APIs because anyone can use them. They’re the API response to open-source software. They don’t cost anything for people to use, and anyone can benefit from them. Google Maps is a good example of an open API. Anyone can go to Google Maps, enter an address, and find the location. The information you submit and the location you receive both pass through an open API.

Why would a company use open API? These types of APIs can offer several benefits. In a previous post, we went into the details of how open APIs can help organizations:

  • Generate leads
  • Develop a community of users (and improve brand awareness)
  • Improve transparency
  • Demonstrate goodwill that attracts potential collaborators

Are you interested in creating and managing open REST APIs without learning a lot of code? DreamFactory lets you manage low-code APIs from an intuitive, user-friendly dashboard. Start your free trial now.

Private APIs

Private APIs are internal APIs that only people within your organization can use. Users will need an API key for account authentication before they can access information guarded behind these types of APIs.

Private APIs have several advantages for organizations that do not want to share data or microservices with the public. You don’t even need to make endpoints visible on the internet. Instead, you can store your private APIs on internal systems.

The obvious disadvantage of this approach is that it becomes more difficult to share information and web services when you want to.

Partner APIs

Partner APIs let you share information and microservices with business partners without compromising security. With these types of APIs, business partners need authentication keys that give them access. Other than this feature, they largely offer the same functionality as private APIs.

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How DreamFactory Can Help

DreamFactory makes it easy for you to create and manage REST APIs. If you have different types of APIs, DreamFactory can convert SOAP to REST. DreamFactory also helps solve the problems that you might encounter with REST and other types of APIs. For example, you can set API limits to prevent endpoints from getting too crowded and slowing down.

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Read More:

A Concise Introduction to REST API