In today’s digital ecosystem, APIs are the backbone that enables seamless communication between different software systems, devices, and platforms. SAP’s Cloud Application Programming Model (CAP) simplifies API development by providing a robust framework for building scalable, maintainable, and enterprise-ready services on the SAP Business Technology Platform (BTP).
This article explores how developers using SAP Business Application Studio (BAS) can leverage CAP to efficiently build APIs, focusing on best practices, architecture, and integration with SAP solutions.
The Cloud Application Programming Model (CAP) is a framework designed by SAP for building full-stack enterprise applications and services. It promotes a declarative approach using Core Data Services (CDS) for data modeling, supports Node.js and Java runtimes, and integrates natively with SAP BTP services.
CAP simplifies API development by automating service creation and providing built-in support for protocols like OData and REST, essential for modern cloud-native applications.
Create .cds files to define entities, types, and relationships.
Example (db/schema.cds):
namespace my.bookshop;
entity Books {
key ID : UUID;
title : String;
author : String;
stock : Integer;
}
Expose your entities via a service definition (srv/service.cds):
using my.bookshop from '../db/schema';
service CatalogService {
entity Books as projection on my.bookshop.Books;
}
Implement service logic in JavaScript or Java files.
Example (srv/service.js):
const cds = require('@sap/cds');
module.exports = cds.service.impl(function() {
this.before('CREATE', 'Books', (req) => {
if (!req.data.title) {
req.error(400, 'Title is mandatory');
}
});
});
Use BAS terminal:
cds run
Access your API endpoint (default at http://localhost:4004) and explore metadata at /catalog/$metadata.
Use BAS deployment tools to push your API to the SAP Business Technology Platform for production use.
CAP revolutionizes API development on SAP BTP by combining a model-driven approach with powerful tools and services, all accessible via SAP Business Application Studio. Whether you are building APIs for SAP Fiori apps, integration scenarios, or custom applications, CAP offers an efficient and standardized way to deliver scalable, secure, and maintainable APIs.
Leveraging CAP within BAS accelerates your development lifecycle and ensures your APIs integrate seamlessly within the SAP ecosystem.