get https://<<tenantUriId>>.api.chassi.com/<<applicationSpaceUriId>>/lifecycle/<<serviceUriVersion>>/external-entity-type-identifiers/
Looks up a specific externalEntityTypeIdentifier by its unique id from the Definitional Application Space.
{
"externalEntityTypeIdentifierId" : "123e4567-e89b-12d3-a456-426655440001",
"dateCreated" : "2016-02-28T16:41:41.090Z",
"lastUpdated" : "2016-02-28T16:41:41.090Z",
"entityTypeIdentifier" : "patientId",
"userCreated" : "true"
}