Discover available Employee Central entities and custom fields dynamically via the SAP SuccessFactors OData v2 $metadata document

Steps

1. Request the /odata/v2/$metadata endpoint on your instance's API server
2. Parse the returned EDMX/XML for EntityType definitions, properties, and NavigationProperty associations
3. Identify custom Metadata Framework (MDF) fields, which appear as additional properties on standard or custom entity types
4. Cache the parsed schema locally and use it to validate field names before building queries
5. Re-fetch and diff $metadata after each SuccessFactors release cycle