ABAP Cloud / Clean Core

Guide for developing with the ABAP Cloud programming model, understanding the 3-tier extensibility model, and applying clean core principles.

Workflow

1. Determine the user's context:

   • Understanding ABAP Cloud concepts and restrictions
   • Choosing the right extensibility tier
   • Wrapping unreleased APIs for use in ABAP Cloud
   • Identifying released API alternatives
   • Setting up clean core-compliant development

2. Identify the extensibility tier:

   • Tier 1: Key user extensibility (no code)
   • Tier 2: Developer extensibility (ABAP Cloud / ABAP for Cloud Development)
   • Tier 3: Classic extensibility (standard ABAP, only on-premise/private cloud)

3. Guide implementation using clean core principles

ABAP Language Versions

Language Version	Scope	Available In
ABAP for Cloud Development	Only released APIs and objects; restricted syntax; no SAP GUI	BTP ABAP Environment, S/4HANA (embedded Steampunk)
Standard ABAP	Full ABAP syntax; all repository objects accessible	On-premise, private cloud

Key Restrictions in ABAP for Cloud Development

• Only released SAP APIs (C1 contract) can be used
• No direct database table access for SAP tables (use released CDS views instead)
• No classic dynpro, selection screens, or SAP GUI-dependent statements
• No CALL TRANSACTION, SUBMIT, AUTHORITY-CHECK (use CL_ABAP_AUTHORIZATION instead)
• No classic BAdIs or user exits
• No EXEC SQL or native SQL (use ABAP SQL or AMDP)
• No function modules (except released RFC-enabled ones)
• No INCLUDE programs
• No WRITE or classic list output
• Must use if_oo_adt_classrun for console output

3-Tier Extensibility Model

Tier 1 — Key User Extensibility (No Code)

• Custom fields and logic via SAP Fiori UIs
• Custom CDS views (basic)
• Custom business objects (simple)
• Custom analytical queries
• No ABAP development required

Tier 2 — Developer Extensibility (ABAP Cloud)

• ABAP for Cloud Development language version
• Only released APIs with stability contracts
• RAP-based business objects
• Side-by-side or embedded development
• Full lifecycle management via ADT

"Example: Tier 2 class using only released APIs
CLASS zcl_my_extension DEFINITION
  PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    INTERFACES if_oo_adt_classrun.
ENDCLASS.

CLASS zcl_my_extension IMPLEMENTATION.
  METHOD if_oo_adt_classrun~main.
    "Only released CDS views — no direct table access
    SELECT FROM I_BusinessPartner
      FIELDS BusinessPartner, BusinessPartnerName
      INTO TABLE @DATA(partners)
      UP TO 10 ROWS.
    out->write( partners ).
  ENDMETHOD.
ENDCLASS.

Tier 3 — Classic Extensibility (Standard ABAP)

• Full ABAP language scope
• Access to all repository objects
• Classic enhancement points, BAdIs, user exits
• Only available on-premise or private cloud
• Not recommended for new cloud-ready development

Wrapper Pattern

When a needed API is not released (Level B/C), create a wrapper in Tier 3 that exposes the functionality via a released interface consumable from Tier 2.

Wrapper Class Pattern

"Tier 3: Wrapper class (Standard ABAP language version)
"Released with C1 contract for use from Tier 2
CLASS zcl_wrapper_material DEFINITION
  PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    INTERFACES zif_material_reader.
    "Set as released API with C1 contract in ADT
ENDCLASS.

CLASS zcl_wrapper_material IMPLEMENTATION.
  METHOD zif_material_reader~get_material.
    "Access unreleased API internally
    SELECT SINGLE * FROM mara
      WHERE matnr = @iv_matnr
      INTO @DATA(ls_mara).
    "Map to released structure
    rs_material = VALUE #(
      matnr = ls_mara-matnr
      mtart = ls_mara-mtart
      matkl = ls_mara-matkl ).
  ENDMETHOD.
ENDCLASS.

Wrapper via RFC Proxy (Remote Tier 2 to Tier 3)

"Tier 2 consumer calls released RFC wrapper
DATA(lo_dest) = cl_rfc_destination_provider=>create_by_comm_arrangement(
  comm_scenario  = 'Z_MY_COMM_SCENARIO'
  service_id     = 'Z_MY_OUTBOUND_SRV' ).

CALL FUNCTION 'Z_WRAPPER_FM'
  DESTINATION lo_dest->get_destination_name( )
  EXPORTING iv_param = lv_value
  IMPORTING ev_result = lv_result.

Released API Discovery

Method	Description
ADT: Released Object Search	In ADT, search with api: prefix (e.g., api:cl_*)
Cloudification API Viewer	Browse at https://sap.github.io/abap-atc-cr-cv-s4hc/
ATC Cloud Readiness Check	Run ATC checks to identify unreleased API usage
Released ABAP Classes skill	Use released-abap-classes skill for common released classes
XCO Library	XCO_CP_* classes provide cloud-ready alternatives

Common Unreleased → Released Replacements

Unreleased (Classic)	Released Alternative (ABAP Cloud)
AUTHORITY-CHECK	CL_ABAP_AUTHORIZATION=>check_authorization()
sy-uname	cl_abap_context_info=>get_user_technical_name()
sy-datum / sy-uzeit	cl_abap_context_info=>get_system_date/time()
cl_gui_frontend_services	Not available — use Fiori UI instead
CALL TRANSACTION	RAP action or Fiori navigation
SUBMIT ... AND RETURN	Background job via CL_APJ_RT_API
Direct SAP table SELECT	Use released CDS view (I_* views)
CONVERSION_EXIT_*	CL_ABAP_CONV_CODEPAGE, domain fixed values
BAPI_* function modules	Released APIs or RAP BO consumption
Classic MESSAGE statement	RAP messages via REPORTED

Output Format

When helping with ABAP Cloud / clean core topics, structure responses as:

## ABAP Cloud Guidance

### Context

- Extensibility tier: [Tier 1/2/3]
- Language version: [ABAP for Cloud Development / Standard ABAP]
- Target platform: [BTP / S/4HANA embedded / on-premise]

### Recommendation

[Guidance on the approach]

### Code Example

[ABAP code following clean core principles]

### Released API References

- [List of relevant released APIs used]

References

• SAP Cloudification Repository: https://github.com/SAP/abap-atc-cr-cv-s4hc
• ABAP Cloud Cheat Sheet: https://github.com/SAP-samples/abap-cheat-sheets
• Clean Core Guidelines: https://help.sap.com/docs/abap-cloud