Vulcan Reaches Epic: Our First Live FHIR Handshake
When we introduced Vulcan, our FHIR ingestion engine, it could do something impressive and something frustrating at the same time. It implemented the full SMART Backend Services client flow — sign a JWT, exchange it for a token, kick off a Bulk Data $export, poll for completion, download NDJSON, map it into OMOP CDM. Every step worked. Every test passed.
Against a mock server.
A mock server is a generous conversation partner. You hand it a signed assertion and it hands back a token without looking too closely. A real electronic health record system — Epic, in particular — is not so generous. Before Epic issues you a token, it wants to verify the signature on your assertion. And to do that, it needs something Vulcan had never been built to provide: a way to find our public key.
This is the story of building the missing half of that trust relationship, and of the moment Vulcan stopped talking to mocks and completed its first live handshake with the Epic on FHIR sandbox.