C1 Contract Rules for Providing CDS Entities

A provider of ABAP CDS objects must obey the following rules:

CDS Entities
- Only CDS DDIC-based views (obsolete), CDS view entities, CDS projection views and CDS abstract entities can be released with a C1 contract.
- The usage of upper and lower case in the name of an entity, its associations, elements or parameters must not be changed.
- The client handling must not be changed.
- Being a root entity of a RAP BO cannot be undone.
- Only annotations can be used that are allowed by the annotation @CompatibilityContract.rc.usageAllowed in their definition. Changes to annotations are also governed by its definition.
- Parameters must not be removed from or added to the parameter interface.
- Associations to a released target data source must not be removed and the target data source must not be exchanged.
- No implicit SELECT list * is allowed.
- Only positions of non-key elements can be changed if allowed by the data category.
- Only non-key elements can be added.
- Changes to the elementary data types of elements and parameters are allowed but must follow the rules for elementary data types.
CDS behavior definitions
- Behavior definitions must follow strict mode, must not be managed by BOPF and can only be released for language version ABAP for Cloud Development. The release is restricted to interfaces and abstract entities.
- The underlying CDS entity must be released and CREATE operations are allowed for the root node only.
- Parameters and results of actions and functions must be DDIC data elements or CDS entities.