Construct an XCPD Patient Location Query (ITI-55) SOAP message containing a PRPA_IN201305UV02 HL7v3 payload with the patient's known demographics (name, DOB, gender, address)
Send the request from the Initiating Gateway to one or more Responding Gateways' ITI-55 endpoints
Parse the PRPA_IN201306UV02 response to extract matched patient identifiers from each responding community, including the community-specific patientId and homeCommunityId
Evaluate the match quality indicator (acknowledgeCode and queryResponseCode) — AA indicates an exact match, AE a partial match requiring manual review
Store the discovered community patient identifiers for use in subsequent XCA Cross-Gateway Query (ITI-38) requests scoped to specific communities
Known gotchas
XCPD uses HL7v3 CDA-style XML payloads rather than FHIR or HL7v2, which requires a different XML namespace handling and schema validation compared to other IHE transactions
Many communities require a minimum set of demographic fields (typically name plus DOB plus gender) before responding; supplying only a partial demographic set may result in no match even for patients who exist in the remote system
The patient ID returned by XCPD is community-specific and must not be conflated with the local patient identifier — always carry the homeCommunityId alongside the remote patientId
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp