Building a Multi-Provider SMART on FHIR Backend for Patient Health Record Access

D4CG's SMART on FHIR application gives patients autonomy over their Electronic Health Records, enabling them to share records with researchers. The current backend supports only Epic's sandbox environment, discards OAuth tokens after exchange, and uses in-memory state management that cannot scale. This project builds a production-ready multi-provider backend that supports Epic, Cerner, and any generic SMART-compliant provider. It replaces the current in-memory architecture with database-backed token persistence, adds enhanced provider search via the ONC Lantern registry, and delivers a tested, documented, and containerized API.