Behavior Definition (BDEF)BDEF
What it is
The DDL artefact (object type BDEF) that declares a RAP business object's behavior: which operations it supports (create/update/delete), its determinations, validations, actions, draft enablement, locking and field controls. The matching behavior implementation (ABAP class) holds the logic.
Why it matters for Clean Core
The BDEF is the declarative contract for what the BO can do — RAP reads it to generate the runtime. Getting the BDEF right (managed vs unmanaged, draft, strict mode) shapes the whole object.
Common pitfall
Putting business logic in the BDEF. The BDEF declares; the behavior pool (implementation class) implements. Forgetting to mark `strict ( 2 )` is the other classic miss — it's what surfaces modern syntax checks.