What is the RAP (RESTful ABAP Programming) model?

RAP is SAP's modern framework for building business applications (particularly Fiori apps and OData services) with a standardized, metadata-driven architecture — combining CDS Views (data modeling), behavior definitions (business logic like create/update/delete rules, validations), and service definitions/bindings (exposing everything as OData) into one coherent development model.

flowchart LR
    A[CDS View - data model] --> B[Behavior Definition - business logic]
    B --> C[Service Definition/Binding - OData exposure]
    C --> D[Fiori App consumes the service]

It's the successor to older approaches (like classical BAPI-based development or the earlier draft of OData service generation) for building new, cloud-ready SAP applications, designed to work consistently whether the target is an on-premise S/4HANA system or SAP BTP — a deliberate architectural convergence so developers aren't learning entirely separate models depending on deployment target.