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Side-by-Side Extensions on SAP BTP (formerly "SAP Extension Suite") — Clean Core in the AI Era

As of 2026-10-06

Edited by Cédric Mary, sole editor and publication director — 27 years in the SAP ecosystem. How these pages are produced, and where automation is used.

What is Side-by-Side Extensions on SAP BTP (formerly "SAP Extension Suite")?

"SAP Extension Suite" is a retired label: SAP now frames extensions through SAP Build, ABAP Cloud and the clean core levels A–D. Side-by-side on SAP BTP remains the upgrade-safe pattern — and in 2026 it is also where AI agents, MCP servers and A2A agents are built, under the SAP API Policy.

What it is — and why the name changed

"SAP Extension Suite" was the earlier SAP label for the BTP services used to extend SAP applications (development tools, workflow, portals). SAP no longer organises its message that way: its learning journey "Developing with SAP Extension Suite" was renamed "Building side-by-side extensions on SAP BTP", and the tools were consolidated under SAP Build (Build Code, Build Apps, Build Process Automation, Build Work Zone) with ABAP Cloud joining SAP Build from TechEd 2024. The principle behind the old label is unchanged: extend SAP applications without modifying them, through stable, released interfaces — the clean core.

Clean core levels A–D (the 2025 model)

In August 2025 SAP replaced its binary three-tier extensibility model with a clean core level concept that grades every extension:

Level A — Extend with SAP Build. Only publicly released, stable SAP interfaces backed by stability contracts: side-by-side on SAP BTP (CAP, ABAP Cloud in BTP ABAP environment, low-code) or on-stack with ABAP Cloud.
Level B — Leverage classic APIs. Classic ABAP technologies and SAP classic APIs used as SAP recommends, with documented, upgrade-stable interfaces.
Level C — Accesses internal objects. Uses SAP internal objects; supported for legacy scenarios with changelogs to plan upgrades.
Level D — Not recommended. Modifications or non-recommended objects and techniques; technical debt.

Side-by-side extensions on BTP are Level A by construction when they only consume published APIs — which is exactly why they remain the default for new, non-trivial extensions.

Why it matters

"SAP Extension Suite" is no longer how SAP names this space — SAP Build, ABAP Cloud and clean core levels A–D are the current vocabulary clients and SAP account teams use.
Side-by-side extensions on released APIs are clean core Level A by construction; the same extension calling internal objects drops to Level C or D.
In 2026 extensions increasingly are agents or agent tools (CAP @mcp, CAP A2A agents, Integration Suite MCP servers) and fall under SAP API Policy v.4.2026a.

Key points

"SAP Extension Suite" is a retired label; SAP's learning journey was renamed "Building side-by-side extensions on SAP BTP" and tools sit in SAP Build.
Clean core levels (Aug 2025): A = SAP Build / released APIs, B = classic APIs as recommended, C = internal objects, D = not recommended.
Building blocks: CAP (Node.js/Java), Fiori/UI5, SAP Build Apps, Build Process Automation, Integration Suite, Cloud Foundry or Kyma, BTP ABAP environment.
Choose side-by-side for own data, users, lifecycle, non-SAP integration or AI; on-stack ABAP Cloud for in-transaction logic; key-user extensibility for small changes.
CAP native AI: embeddings, @cap-js/mcp (MCP), @cap-js/agents (A2A) — for custom services, not as proxies of SAP APIs.
SAP API Policy v.4.2026a: Published APIs only; agentic use of SAP APIs via endorsed pathways.

Terms used on this page

Clean core: Principle of extending SAP applications only through released, stable interfaces so upgrades do not break custom code; graded since 2025 in levels A–D.
Side-by-side extension: Extension running on SAP BTP, outside the SAP application, integrated through published APIs and events.
ABAP Cloud: ABAP development model restricted to released APIs, usable on-stack in S/4HANA or in the SAP BTP ABAP environment; part of SAP Build since TechEd 2024.
CAP (SAP Cloud Application Programming Model): SAP's framework for services and apps on BTP in Node.js or Java, now with native AI features (embeddings, MCP adapter, agents plugin).
Kyma: SAP BTP's managed Kubernetes runtime, suited to containers, custom stacks and event-driven microservices.
Cloud Foundry: SAP BTP's managed PaaS runtime, the simplest target for CAP applications.

Sources

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