In the ever-evolving landscape of enterprise application development, the SAP ABAP RESTful Application Programming (RAP) model emerges as a transformative framework, seamlessly connecting the robust capabilities of SAP’s Advanced Business Application Programming (ABAP) landscape with the principles of modern RESTful web services.

This innovative approach empowers developers within the SAP ecosystem to effortlessly create and consume RESTful APIs, fostering efficient integration with external systems and unlocking new levels of flexibility in data exchange.

In this article, we’ll discuss the core components and capabilities of the SAP ABAP RESTful Application Programming model, how it helps companies remain agile in an ever-changing application development environment, and where our expert SAP consultants can come in to help.

What is RESTful Programming?

The ABAP RESTful Application Programming (RAP) model is a critical component of the ABAP Cloud, the core development model that enables users to build cloud-ready business services, applications, and extensions within the SAP BTP, SAP HANA, and SAP S/4HANA Cloud environments.

With the ABAP RESTful Programming model, users can leverage a comprehensive set of languages, tools, frameworks, and data models to build cloud-ready enterprise applications and simplified Web APIs and easily extend existing SAP applications to the ABAP environment.

RAP in ABAP offers a standardized development flow based on the ABAP language, Core Data Services (CDS), and other business services in the Eclipse-based ABAP Development landscape.

What is RAP in SAP?

With the evolution of intelligent, cloud-based technical landscapes comes increased requirements for artificial intelligence, embedded analytics, and other modern business objects. To help organizations meet the advanced requirements of modern solutions like SAP HANA, SAP Fiori, and other SAP Cloud applications, SAP offers the ABAP RESTful Application Programming model (RAP).

The RAP model offers pre-built options for testing, documentation, extensibility, and overall system support, enabling users to develop and manage various business events and services in one location and improve knowledge transfer across teams and systems.

Users can leverage RAP functionality to develop different services and local APIs, like:

  • Upgrade-safe, lifecycle-stable local APIs via RAP business object interfaces
  • SQL-based services for intelligent data integration
  • OData-based services exposed as Web APIs
  • InA-based analytical services for building analytical apps in SAP Analytics Cloud
  • Business events used for asynchronous communication about changes to RAP business objects
  • OData-based services for UI development and the creation of new SAP Fiori apps

Critical Components of the ABAP Programming Model

At its core, SAP ABAP RAP enables developers to create and consume RESTful APIs, fostering agile application development and facilitating seamless integration with external systems.

Leveraging the widely adopted OData protocol, it aligns SAP applications with contemporary development standards, ensuring compatibility and collaboration across diverse platforms.

Here are a few critical components of the ABAP RESTful Application Programming model:


A query is a connecting interface used for read-only access to the database in OData services, enabling users to generate lists or analytical reports to process data and gain better insights.

Queries are the non-transactional counterparts of business objects, comprising a data model, a runtime, and generic and modeled query capabilities.

While the combination of an intuitive data model, runtime, and query capabilities originates in the concept of business objects, a query provides read-only access to the database and its runtime never modifies data but only retrieves structured data from the database.

Business Object

In the ABAP development platform, a business object (BO) refers to a data (or composition) model and its transactional behavior, typically used to represent a real-world business entity, such as a Product or Sales order, in the enterprise development flow.

The RAP model offers several runtime implementation types used to implement behavior in transactional business objects, including managed BO implementations that use a greenfield approach and unmanaged BO implementations that use a brownfield approach.

A business object typically contains the following components:

  • Standard transactional operations to create, delete, and update business data
  • Multiple nodes for specific transactional behavior, like the SalesOrder root node and its child nodes ScheduleLine and SalesOrderItems
  • Application-specific nonstandard transactional operations

Business Service

The ABAP development platform can act as either a service provider or a service consumer, for example, the SAP Fiori UI client.

A business service in the context of the ABAP RESTful Application Programming model refers to a RESTful service that can be called directly by a consumer.

Business services expose both the data model and its associated behavior by outlining a specific service definition and service binding.

Core Implementation Languages for the ABAP Data Model

Here are the main implementation languages leveraged in the RESTful Application Programming model:

Entity Manipulation Language (EML)

Entity Manipulation Language (EML) provides an SQL-like syntax that enables application developers to implement and manage the transactional behavior of business objects in the RAP model.

EML offers type-safe, API-based access to RAP business objects both within and outside of the concept of the ABAP RESTful Application Programming model.

Modern ABAP Language

The recent modernization of the ABAP Programming model focuses on the simplification of application programming, development, and deployment and offers expression-oriented language to help developers write concise ABAP code.

With modern ABAP features, like new operation constructors, inline declarations with type inference, and grouping, filtering, and virtual sorting processes for internal tables. The ABAP Programming model can also be extended with EML functionality, enabling users to control the transactional behavior of their RAP business objects.

Core Data Services (CDS)

ABAP Core Data Services (ABAP CDS) provide an intelligent service model infrastructure to define semantically rich data models and streamlined access to advanced SAP HANA data libraries through advanced CDS table functions.

In recent versions, the data definition language in ABAP CDS is enhanced to support the definition, composition, and management of transactional behavior models in the native ABAP RESTful Application Programming landscape.

Use Cases for the ABAP RESTful Application Programming Model

Here’s a closer look at a few common use cases for the RESTful Application Programming model:

  1. No custom code

When organizations want to build new custom applications, APIs, or rich program extensions from scratch, or through greenfield implementations, a managed business object implementation is recommended. The ABAP RESTful Application Programming model offers built-in support to manage and optimize the implementation of new applications without custom code.

  1. Loosely coupled, reusable custom code

When organizations are looking to modernize their existing enterprise applications, business logic decoupled from technical aspects, like UI protocols, and reusable custom code can help save the business object runtime sequence for building new applications.

Here are a few key examples of loosely coupled custom code in the SAP ABAP landscape:

  • Applications built in accordance with the BOPF framework
  • Function modules, BAPIs, and object-oriented custom APIs that don’t perform COMMIT statements when executed

In any situation where loosely coupled code is concerned, users should consider either an unmanaged BO implementation or a managed BO with unmanaged save implementation.

  1. Tightly coupled custom code

Custom code that is tightly coupled to existing technical aspects can be difficult to maintain, especially when users are trying to innovate existing applications and reuse custom business logic from the apps at the same time.

Here are a few examples of existing applications within the SAP landscape:

  • Code-based OData services implementation without CDS in the SAP Gateway Service Builder with the help of the Model Provider and Data Provider classes
  • Dynpro or web dynpro-based applications with tightly coupled business logic and UI logic

In situations where the existing custom code can be decoupled and reused for a new task, users should leverage the managed BO with unmanaged save implementation, enabling the RAP framework to manage a significant portion of the business object runtime.

  1. Custom code from ABAP model for SAP Fiori

By leveraging CDS-based BOPF business objects and their implemented business logic, organizations can modernize existing applications built with the ABAP Programming model for SAP Fiori and access the core advantages of RAP in SAP.

In these scenarios, it is recommended that users leverage the BOPF-managed BO implementation, which is designed specifically for CDS-based BOPF BOs in an existing SAP landscape.

Top 5 Advantages of the ABAP RESTful Programming Model

Here’s a closer look at a few critical advantages of the RAP model for business users:

Enhanced System Agility

Business Process Optimization: The SAP ABAP RAP model enables the rapid development and deployment of critical applications, allowing businesses to optimize and adapt their processes more quickly and stay adept to rapid adjustments to workflows and applications over time.

Simplified Data Access

User-Friendly APIs: SAP ABAP RAP simplifies data access by offering user-friendly APIs that enable business users to easily consume and manipulate data from SAP systems without requiring extensive technical knowledge. This simplicity enhances user engagement and reduces dependency on IT teams for data retrieval and analysis.

Integration with External Systems

Interoperability: The RESTful nature of the RAP model facilitates seamless integration with external systems, providing users with the ability to connect SAP applications to various external platforms and services. This promotes a more connected and collaborative technical ecosystem, streamlining data exchange between different systems and improving productivity across the board.

Improved User Experience

Responsive Applications: SAP ABAP RAP facilitates the development of responsive and user-friendly applications, allowing users to experience improved interfaces, smoother navigation, and quicker response times. This is particularly valuable for applications accessed via web browsers or mobile devices.

Modern Application Standards

Support for OData Protocol: The RAP model often leverages the standard OData protocol, a widely adopted data standard for building RESTful APIs. This ensures that SAP applications built with ABAP RAP adhere to modern development standards and are compatible with a broad range of technologies, enabling better collaboration with external developers, applications, and systems.

Potential Challenges in Implementing SAP ABAP RAP

When implementing the SAP ABAP RESTful Application Programming model, there are a few common challenges users must be aware of, understand, and combat effectively. Here’s a closer look at a few of the main challenges companies typically face in ABAP RAP implementation:

Customization Complexity: The customization of SAP ABAP RAP to align with specific business processes can be intricate, leading to potential complexities in adapting the model to unique organizational requirements.

Data Migration Issues: The transition from legacy systems to SAP ABAP RAP may encounter challenges related to data migration, including data cleansing, validation, and mapping, which are critical for maintaining data accuracy.

User Adoption: Resistance to change among end-users may pose a challenge, as adapting to new user interfaces and workflows can be met with skepticism and necessitates effective change management strategies.

Integration with Legacy Systems: Ensuring seamless integration with existing legacy systems and technologies may be challenging, requiring thorough planning and potentially the development of middleware solutions.

Key Strategies for Overcoming Common Obstacles

While it’s one thing to understand the most common challenges associated with ABAP RAP implementation, users should also understand the best practices used to overcome each challenge.

Here are a few critical business strategies to improve implementation efficiency for your team:

Comprehensive Training Programs: Addressing user adoption challenges can be mitigated through comprehensive training programs. Providing users with the knowledge and skills to navigate the new system can boost confidence and minimize resistance.

Phased Implementation: Breaking down the implementation into phases allows for better control over customization and data migration processes. It also facilitates a gradual transition, reducing the impact on daily operations.

Engage Stakeholders: Involving key stakeholders early in the process ensures that their insights and concerns are considered. This proactive engagement fosters a sense of ownership and can help preempt potential issues.

Thorough Testing Protocols: Implementing rigorous testing, including unit testing, integration testing, and user acceptance testing, can identify and rectify issues before the full-scale deployment, ensuring a smoother transition.

How Can We Help?

Whether you need help navigating a new SAP BTP ABAP environment, additional support setting up structured data retrieval across your existing SAP system, or just an extra hand getting started on your journey with SAP HANA or S/4HANA, Surety Systems is here to help.

Our senior-level, US-based SAP consultant team has the knowledge, skills, and experience to handle your most critical project needs and help you maximize your investment over time.

Getting Started with Us

Interested in learning how the SAP ABAP RESTful Application Programming model can ensure the efficient development of new SAP Fiori apps or Web APIs across your existing SAP landscape? Ready to get started on a project with our team of expert SAP consultants?

Contact us today for more information!