The Clean Core strategy is an architectural design principle that keeps the SAP standard ERP core software free of custom modifications. Custom extensions are developed either "in-app" using key-user extensibility or "side-by-side" on the SAP Business Technology Platform (BTP). This decoupling allows businesses to upgrade their core ERP system instantly, reduce technical debt, and ensure continuous innovation without breaking custom business logic.
Knowledge Hub
Clean Core & BTP Reference Hub
Discover the technical architectures, security guidelines, and extensibility patterns aligned with SAP's published Clean Core guidelines for S/4HANA.
Naming note: since SAP Sapphire 2026, SAP BTP sits under the SAP Business AI Platform (BAIP) umbrella together with SAP Business Data Cloud and SAP Business AI. This is a portfolio consolidation, not a retirement of SAP BTP — the services keep their names, and SAP shipped releases under the name “SAP BTP ABAP environment” as recently as August 2026. We use SAP BTP for the concrete services and SAP BAIP for the portfolio around them.
Quick Answer
SAP Clean Core is a set of guiding principles for keeping the S/4HANA core standard and upgradeable across five dimensions — business processes, extensibility (custom code), data, integration, and operations. A Clean Core assessment measures maturity across those dimensions. For the extensibility dimension specifically it means getting object-level visibility into custom ABAP (what touches standard tables or unreleased objects) and attaching KPIs — a Clean Core Score and an A–D readiness grade derived from SAP’s own published object data — so the highest-risk objects are remediated first. It is complementary to SAP ADT/ATC and the SAP toolchain (Cloud ALM, LeanIX, Signavio), which remain the authoritative checks.
Frequently Asked Questions
Structured architectural explanations for developers and crawler extraction
In-App RAP (ABAP RESTful Application Programming Model) runs directly within the S/4HANA tenant. It is ideal for extending standard SAP business objects and UI layers using native ABAP in a cloud-compliant way. Side-by-Side CAP (Cloud Application Programming Model) runs externally on SAP BTP, typically using Node.js or Java. It is designed for standalone cloud-native applications, multi-tenant SaaS products, and integration with non-SAP systems, fully decoupling execution from the ERP core.
Clean-Core.io configures secure tunnels and authentication pathways on SAP BTP. It implements JSON Web Tokens (JWT) validated by the SAP XSUAA (Extended Services for User Account and Authentication) service. This allows stateless, secure API communication and enforces role-based access control (RBAC). For S/4HANA core connections, it uses SAP BTP Connectivity and Destination services, routing RFC and OData traffic securely via SAP Cloud Connector without exposing internal endpoints.
BYOT lets a developer connect their own non-production S/4HANA sandbox so generated tests can run against a real OData service. It is read-only, credentials are encrypted at rest (AES-256-GCM) in a server-only store, production endpoints are blocked, and every connection is admin-gated (manually reviewed and approved) before activation. Clean-Core.io does not host or persist your ERP data — SAP transaction data is processed statelessly in memory. The feature is free; access is granted by an administrator, not by paying for a tier.
A deterministic ABAP evidence engine parses the custom code first (classes, reports, function modules, custom Z-tables, SQL) and produces auditable facts — a code inventory, findings, complexity/criticality scores, and a RAP-vs-CAP routing recommendation. Google Gemini then narrates and drafts modern TypeScript/Node.js (CAP) or ABAP Cloud (RAP) on top of that evidence, and can generate draft test suites and BPMN 2.0 blueprints for Signavio. All AI output is a draft for architect review — it accelerates the assessment and complements SAP's own tooling.
Key Terms
A quick glossary mapping technical SAP terms to modern integration architectures:
- SAP BTP (Business Technology Platform)
- The integration and extension platform for SAP applications. It enables the development of side-by-side extensions, data orchestration, and custom cloud-native business processes separate from the ERP core. Since SAP Sapphire 2026 it sits under the SAP Business AI Platform (BAIP) umbrella together with SAP Business Data Cloud and SAP Business AI; the BTP services and the product name "SAP BTP ABAP environment" continue unchanged.
- SAP Cloud Connector
- A secure software link that runs inside the customer's on-premise or private cloud network, establishing an encrypted TLS connection to SAP BTP without requiring complex inbound firewall configurations.
- OData (Open Data Protocol)
- An OASIS standard protocol defining best practices for building and consuming RESTful APIs. It is the default communication standard for SAP S/4HANA business services.
- CDS (Core Data Services)
- The data modeling infrastructure used by SAP. CDS views define database tables, relationships, and service projections declaratively inside both the ABAP environment (RAP) and the Node.js/Java environment (CAP).
Extensibility Paradigm Comparison
Decision framework comparing SAP RAP and BTP CAP extension routes
| Feature / Criteria | In-App RAP (ABAP RESTful) | Side-by-Side CAP (SAP BTP) |
|---|---|---|
| Runtime Environment | Directly inside SAP S/4HANA (ABAP stack) | SAP BTP (Node.js, Java, Cloud Foundry/Kyma) |
| Primary Use Case | Modifying/enhancing standard SAP business logic | Standalone apps, partner SaaS, multi-system integration |
| Development Languages | Modern ABAP (Cloud-enabled subset) | JavaScript, TypeScript, Java |
| Database Access | Native SQL on HANA via CDS views | OData, REST, or database targets (HANA, PG, SQLite) |
| Core Decoupling | High logical coupling (shares SAP memory) | Complete architectural separation (connected via APIs) |
| Upgrade Impact | Zero impact (uses officially released SAP APIs) | Zero impact (completely independent execution) |
Clean Core Extensibility Alignment
Clean-Core.io leverages standard SAP technologies, securing transactions according to the SAP Cloud SDK guidelines. Keep your ERP core system upgradeable while expanding functionality with cloud-native scalability.
Clean Core Aligned Strategy