Workday RaaS, SOAP, and REST: what can a unified API abstract?

The reviewed evidence supports a narrow Workday boundary. A unified layer can map selected source fields into its normalized model, while Workday still exposes tenant-owned surfaces and permissions. Workday publishes an official SOAP reference; Unified.to describes SOAP, REST, and RaaS roles; public Bindbee evidence reviewed here establishes custom-field mapping, not full Workday surface support.