Spine Directory Service

Overview of the role of the Spine Directory Services (SDS) for Visitors and Migrants.

Warning: We need to confirm with the Spine team the expectations for clients - do they need to query SDS to get the Spine’s ASID or can they use a fixed value? If they need to look it up, can they cache it, and for how long?

Spine Directory Service (SDS)

Consumer systems are expected to resolve the FHIR endpoint for the Spine using the Spine Directory Service (SDS) LDAP:

This is a two step process, as follows:

Lookup the Accredited System ID (ASID)
Lookup the Message Handling System (MHS)

Once the MHS record has been retrieved the fully qualified domain name (FQDN) of the FHIR server can be extracted.

Accredited System ID (ASID) Lookup

Using the NHS Digital ODS code client’s SHALL lookup the Accredited System ID (ASID) as follows:

Accredited System type
- objectClass = nhsAs
Organisational code
- nhsIDCode = The NHS Digital ODS Code. [TODO: Show the real value for our ODS code]
Interaction ID
- nhsAsSvcIA = [interactionId] of the Visitors and Migrants operation required (either urn:nhs:names:services:visitorsandmigrants:fhir:rest:read:metadata or urn:nhs:names:services:visitorsandmigrants:fhir:rest:search:observation).

ldapsearch -h ldap.spine.nhs.uk –b "ou=services, o=nhs" 
	"(&(nhsIDCode=[odsCode]) (objectClass=nhsAS)(nhsAsSvcIA=[interactionId]))" 
	uniqueIdentifier nhsMhsPartyKey

Message Handling System (MHS) Lookup

Clients SHALL lookup the Party Key / Message Handling System (MHS) as follows:

Message Handling System type
- objectClass = nhsMHS
MHS Part Key
- nhsMHSPartyKey = [partKey] as extracted from the ASID record.
MHS Interaction ID
- nhsMhsSvcIA = [interactionId] as extracted from the ASID record.

The fully qualified domain name of the message handling system can then be extract from the nhsMhsFQDN field of the MHS record (e.g. [system].[vendor].nme.ncrs.nhs.uk).

ldapsearch -h ldap.spine.nhs.uk -b "ou=services, o=nhs" 
	"(&(nhsMhsPartyKey=[partKey]) (objectClass=nhsMhs) (nhsMhsSvcIA=[interactionId]))" 
	nhsMhsEndPoint nhsMhsIsAuthenticated

The FHIR endpoint URL of the message handling system can then be extracted from the nhsMhsEndPoint field of the MHS record.

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