gh-secondsky-sap-skills-skills-sap-btp-developer-guide/references/extensions.md

SAP Solution Extensions Reference

Overview

SAP BTP enables organizations to extend existing SAP solutions without disrupting core performance and business processes. Extensions can add new functionality while maintaining upgrade compatibility.

Extension Types

In-App Extensions

Definition: Extend backend and UI directly within the SAP solution

Supported Products:

• SAP SuccessFactors
• SAP S/4HANA Cloud
• SAP Cloud for Customer

Capabilities:

• Custom fields
• Custom logic (BAdIs)
• UI adaptations
• Custom reports

Side-by-Side Extensions

Definition: Additional functionality deployed on SAP BTP, integrated with SAP solutions

Advantages:

Area	Benefit
Business	Independent feature development
Technology	Modern cloud-native architecture
Operations	Separate lifecycle management

Planning Recommendations

1. Start simple - Begin with straightforward implementations
2. Maintain focused digital core - Keep core system clean
3. Choose simplest approach - Don't over-engineer
4. Verify API/event availability - Ensure integration points exist

Supported SAP Solutions

Solutions with Automated Configuration

Solution	Extension Service
SAP S/4HANA Cloud	SAP S/4HANA Cloud Extensibility
SAP SuccessFactors	SAP SuccessFactors Extensibility
SAP Cloud for Customer	Standard extensibility service
SAP Commerce Cloud	Commerce Cloud extensibility
SAP Field Service Management	FSM extensibility

Extension Use Cases

UI Enhancement

Scenario: Build new SAP Fiori interfaces integrated with SAP solutions

Implementation:

// CAP service consuming S/4HANA API
const cds = require('@sap/cds');

module.exports = (srv) => {
  srv.on('READ', 'BusinessPartners', async (req) => {
    const s4 = await cds.connect.to('API_BUSINESS_PARTNER');
    return s4.run(req.query);
  });
};

Functionality Expansion

Scenario: Connect multiple SAP solutions

Example: Link SAP SuccessFactors employee data with SAP S/4HANA

Advanced Capabilities

Scenarios:

• Add analytics dashboards
• Implement machine learning
• Enable IoT integration

Data Consolidation

Scenario: Centralize insights across systems

Tools:

• SAP Datasphere
• SAP Analytics Cloud
• Custom CAP aggregators

SaaS Ecosystems

Scenario: Create multi-tenant extension applications for distribution

Considerations:

• Subscription management
• Tenant isolation
• Key user extensibility

Implementation Patterns

Remote Service Integration (CAP)

Step 1: Import Service Definition

# Download API specification
cds import API_BUSINESS_PARTNER.edmx

Step 2: Configure Connection

// package.json
{
  "cds": {
    "requires": {
      "API_BUSINESS_PARTNER": {
        "kind": "odata-v2",
        "model": "srv/external/API_BUSINESS_PARTNER",
        "credentials": {
          "destination": "S4HANA"
        }
      }
    }
  }
}

Step 3: Implement Service

// srv/extension-service.js
const cds = require('@sap/cds');

module.exports = cds.service.impl(async function() {
  const s4 = await cds.connect.to('API_BUSINESS_PARTNER');

  this.on('READ', 'BusinessPartners', async (req) => {
    return s4.run(req.query);
  });

  this.on('CREATE', 'LocalEntities', async (req) => {
    // Local business logic
    const data = req.data;
    // Enrich with S/4HANA data
    const bp = await s4.read('A_BusinessPartner').where({ BusinessPartner: data.partnerId });
    data.partnerName = bp[0]?.BusinessPartnerFullName;
    return data;
  });
});

Event-Based Integration

Event Subscription

// srv/extension-service.cds
using { sap.s4.beh } from 'srv/external/OP_API_BUSINESS_PARTNER_SRV';

service ExtensionService {
  // React to S/4HANA events
  event BusinessPartnerChanged : {
    BusinessPartner : String;
  }
}

Event Handler

// srv/extension-service.js
module.exports = (srv) => {
  srv.on('BusinessPartnerChanged', async (msg) => {
    const { BusinessPartner } = msg.data;
    console.log(`Business Partner ${BusinessPartner} changed`);
    // Trigger local business logic
  });
};

Eventing via SAP Event Mesh

# mta.yaml
resources:
  - name: my-event-mesh
    type: org.cloudfoundry.managed-service
    parameters:
      service: enterprise-messaging
      service-plan: default
      config:
        emname: my-namespace

ABAP Extensions (On-Stack)

Developer Extensibility

Available In: SAP S/4HANA Cloud, Private Edition

Capabilities:

• Custom CDS views
• Custom RAP business objects
• Released API consumption

Key User Extensibility

Available In: Multitenant SaaS applications

Capabilities:

• UI adaptations
• Custom fields
• Business Add-Ins (BAdIs)
• Business configuration

Best Practices

Architecture

Principle	Description
Loose coupling	Use APIs/events, not direct DB access
Idempotent operations	Handle duplicate events gracefully
Error handling	Implement retry logic, circuit breakers
Security	Follow least privilege principle

Development

1. Use mock servers for development without production access
2. Test with real data before production deployment
3. Monitor integration health with SAP Cloud ALM
4. Document APIs for maintainability

Operations

1. Separate lifecycles - Deploy extensions independently
2. Version APIs - Maintain compatibility during upgrades
3. Monitor performance - Track integration latency
4. Plan for upgrades - Test against SAP update schedules

Resources

Resource	URL
SAP Extensibility Explorer	https://experience.sap.com/extensibility-explorer/
Discovery Center Missions	https://discovery-center.cloud.sap/
CAP External Services	https://cap.cloud.sap/docs/guides/using-services

Related Skill Guides

Topic	Reference
Design Patterns	references/design-patterns.md - DDD, modularization
Security	references/security.md - Authentication, authorization
Operations	references/operations.md - Scaling, monitoring
Connectivity	references/connectivity.md - Remote services, destinations

Source Documentation

• Extending SAP Solutions: https://github.com/SAP-docs/btp-developer-guide/blob/main/docs/extending-existing-sap-solutions-using-sap-btp-40aa232.md