This is an engine that converts data of one structure to another, based on a configuration file which describes how. There is an accompanying syntax to make writing mappings easier and more robust.
So from what I understand, you will have to provide FHIR ConceptMap(s) to define mapping for the codes from your FHIR resources, such as persons, encounters, conditions, diagnosis, etc to OMOP concept ids and source concept ids. But how many ConceptMaps you will have to define? In OMOP vocabulary, there are 7,961,281 codes for far.
So from what I understand, you will have to provide FHIR ConceptMap(s) to define mapping for the codes from your FHIR resources, such as persons, encounters, conditions, diagnosis, etc to OMOP concept ids and source concept ids. But how many ConceptMaps you will have to define? In OMOP vocabulary, there are 7,961,281 codes for far.