Exploring the Power of REST APIs in Salesforce Marketing Cloud
By: Dennis Chau
Published June 1, 2023 ∙ 10 Minute Read

What Is a REST API?
Simply put, a REST API (Representational State Transfer Application Programming Interface) is a set of guidelines that software systems follow to communicate and exchange data in a standardized fashion.
A predictable and consistent mode of interaction between systems is enabled through it.
It works as an interface, connecting the client application that initiates requests to a server application that processes the request and sends back a response.
However, I believe that the REST API goes beyond being merely a set of guidelines.
This fundamental architectural style puts emphasis on scalability, simplicity, and the use of standard protocols.
The widespread adoption of building web services is due to the influence of the World Wide Web's principles on this architectural style.
How REST APIs Are Integrated Within Marketing Cloud
REST APIs can be used by developers in Salesforce Marketing Cloud to interact with the platform's marketing automation and customer engagement features.
Specifically, they can help with data integration, campaign management, journey automation, content management, reporting, and customization.
I see the integration of REST APIs within Marketing Cloud as a transformative shift in how developers can harness the power of technology to deliver exceptional customer experiences.
They can connect Marketing Cloud to various external systems by utilizing these APIs. Valuable data can be accessed by enabling effortless data integration.
This integration clears the path for customized and focused marketing efforts that truly touch customers on a deeper level.
REST Design Principles
In order for an API to be considered RESTful, it must meet these 6 principles based on the REST architectural style:
1. Client-Server Decoupling: Client and server programs have to be independent.
2. Uniform Interface: API requests for the same resource should look the same.
3. Statelessness: REST APIs follow a stateless approach, requiring that every request include all the necessary information for its processing.
4. Layered System Architecture: Within REST APIs, communication between client and server takes place through distinct layers. REST APIs should be developed in a manner that conceals whether the client and server are communicating with the end application or an intermediary.
5. Cacheable: When it can be done, it is encouraged to enable caching of resources on either the client or server side. Additionally, server responses must include indications regarding the caching permissions for the delivered resource.
6. Code on Demand: REST APIs usually deliver static resources. However, in rare cases, responses might feature executable code, and you should perform the code when necessary.
How REST APIs Work

Resources in REST refer to accessible information (e.g. user profiles, product listings, and blog posts).
To identify every resource, a unique URL named Uniform Resource Identifier (URI) is given.
The client can use four different methods (GET, POST, PUT, DELETE) while sending an HTTP request that specifies what interaction they want with a particular resource on a server.
Provided also is the resource's URI. The server performs the necessary operations on the resource after processing the received request.
An HTTP response containing the requested data or status to indicate the request’s outcome is then sent back.
Resources within a system can be effectively managed through the use of the four key HTTP methods (GET, POST, PUT, DELETE) which directly align with CRUD (Create, Read, Update, Delete) operations:
GET (Read) lets you retrieve existing resource data
POST (Create) lets you create new resources
PUT (Update) lets you update existing resource data
DELETE (Delete) lets you delete existing resources
Real World Implementation of REST APIs
Picture a scenario where you own a clothing business and aim to integrate Salesforce Marketing Cloud with your e-commerce website in order to optimize your marketing operations.
REST APIs can be utilized within Salesforce Marketing Cloud to achieve this task.
Data Synchronization: REST APIs enable you to deliver suitable customer and purchase data to Marketing Cloud. This can be accomplished each time a customer makes an online store purchase. Details contained within this data could include the customer's name, email address, items purchased, order value, and any additional relevant information.
Personalized Email Campaigns: After the customer data has synchronized, you can initiate personalized email campaigns in Marketing Cloud with REST APIs. Specifically, sending welcome emails to new customers, following up on purchases, or reminding customers about abandoned carts can all be done through the API. It allows for the passing of dynamic data such as a customer's name or recently bought items to personalize email content.
Segmentation and Targeting: Custom audience segments based on certain criteria can be created in Marketing Cloud using REST APIs. For example, you can segment your customer base by the type of purchases they've made, customers who haven't made a purchase in a while, or customers who have subscribed to your newsletter. Utilizing segments like these allow you to personalize your marketing campaigns and guarantee that the appropriate audience receives relevant messages.
Marketing Automation: Marketing Cloud workflows can be automated using REST APIs. They enable you to trigger a chain of automated emails depending on customer behavior, like sending a discount offer to customers who have demonstrated an interest in a particular product category. You can provide your customers with timely and relevant communications without manual intervention.
Tracking and Analytics: Specific data from Marketing Cloud, like email open rates, click-through rates, and conversion rates, can be retrieved using REST APIs. Gaining insights into the effectiveness of your marketing campaigns is possible by integrating this data with your e-commerce website or other analytics platforms. Refining your strategies and making data-driven decisions can also be aided by this information.
Ultimately, using REST APIs allows for smooth integration between your e-commerce website and Salesforce Marketing Cloud.
By utilizing this feature, you can implement focused and personalized marketing initiatives that consider customer behavior and preferences.
Final Thoughts
Before writing this article about REST APIs, my knowledge and experience of APIs were limited to having only once worked with a sneaker database API while building a React application in the past.
However, through extensive research and learning, I delved deeper into the world of REST APIs, including their integration within Salesforce Marketing Cloud.
I have gained a thorough understanding of REST principles, HTTP interactions, and how REST APIs can be utilized to streamline marketing processes, automate data transfers, and enhance the overall functionality of Salesforce Marketing Cloud.
This newfound understanding has allowed me to provide comprehensive insights and explanations in this article.
I hope that, just as I expanded my knowledge through the process of writing this article, you have also gained valuable insights and understanding about REST APIs by reading it.
Learn More About REST APIs
Here is a 6-step plan on how you can gain an in-depth understanding of REST APIs:
1. Recognize the Basics: Start with understanding the fundamentals of APIs, REST architecture, and HTTP protocol.
2. Study REST Principles: Dive deeper into the principles and constraints of REST, including resource identification, statelessness, and the proper use of HTTP methods.
3. Understand HTTP: Make sure you’re familiar with concepts like HTTP protocol, including request methods, headers, URL structure, status codes, and message formats like JSON or XML.
4. Select a Programming Language: Choose your favorite programming language because you will be using it to work with REST APIs.
5. Hands-on Practice: Practice by finding reliable REST APIs with proper documentation and making straightforward requests to retrieve data. Gain an understanding of handling responses and errors through practice with CRUD operations (Create, Read, Update, Delete).
6. Build a Project: Apply your knowledge by building a small project that integrates with a REST API. Work with advanced functionality like pagination or filtering, implement authentication and handle various endpoints.
REST API Resources
Here are some useful links to learn more about REST APIs: