Configuring FHIR Mapper on Vonk

To configure the FHIR Mapper in your Vonk installation, follow the steps below. If you don’t have a copy yet, get in touch with us if you’re interested in purchasing it for your needs.

Load the engine

  1. Ensure the /plugins directory exists in your Vonk installation.

    1.1. The location of this folder is customisable via the PluginDirectory property, so if you chose a different directory, ensure it exists instead.

  2. Place the all of the received DLL’s into the plugins directory:

  • Hl7.Fhir.Language.dll
  • Hl7.Fhir.Mapping.dll
  • Hl7.Fhir.Mapping.STU3.Poco.dll
  • Superpower.dll
  • Vonk.Plugin.BinaryWrapper.dll
  • Vonk.Plugin.MappingToStructureMap.dll
  • Vonk.Plugin.TransformOperation.dll
  1. Configure the Vonk settings and add $convert to WholeSystemInteractions to declare support for the convert operation.

  2. Similarly, add $transform to InstanceLevelInteractions to declare support for the transform operation. Sample configuration:

    "SupportedInteractions": {
      "InstanceLevelInteractions": "read, vread, update, delete, history, conditional_delete, conditional_update, $validate, $validate-code, $expand, $compose, $meta, $meta-add, $transform",
      "TypeLevelInteractions": "create, search, history, conditional_create, compartment_type_search, $validate, $snapshot, $validate-code, $expand, $lookup, $compose",
      "WholeSystemInteractions": "capabilities, batch, transaction, history, search, compartment_system_search, $validate, $convert"
  3. Update the / path of PipelineOptions to load the mapping engine plugin by including the following namespaces:

    "Vonk.Plugin.BinaryWrapper", "Vonk.Plugin.MappingToStructureMap",

Sample configuration:

"PipelineOptions": {
  "PluginDirectory": "./plugins",
  "Branches": [
      "Path": "/",
      "Include": [
  1. Start Vonk :)


To verify that the mapping engine is loaded, do check the metadata with http(s)://<vonk-endpoint>/metadata. If it mentions this in the response:

  "name": "transform",
  "definition": {
    "reference": ""

That means the plugin is loaded and working.

(alternatively, run curl -s http://localhost:4080/metadata | jq ".rest[].operation[] | select (.name == \"transform\")")


If the verification didn’t work for some reason, check the Vonk logs for the following:

  1. In the Looking for Configuration in these assemblies section, ensure the dll’s are loaded:

    <path to vonk>/plugins/Hl7.Fhir.Language.dll
    <path to vonk>/plugins/Superpower.dll
    <path to vonk>/plugins/Vonk.Plugin.TransformOperation.dll
    <path to vonk>/plugins/Vonk.Plugin.BinaryWrapper.dll
    <path to vonk>/plugins/Vonk.Plugin.MappingToStructureMap.dll
    <path to vonk>/plugins/Hl7.Fhir.Mapping.STU3.Poco.dll
    <path to vonk>/plugins/Hl7.Fhir.Mapping.dll

If they’re not listed, check that the dll files are available in your PluginDirectory directory (./plugins by default).

  1. Ensure the plugins are being registered with the Vonk pipeline:

        MappingToStructureMapConfiguration [4550] | Services: V | Pipeline: V
        TransfromOperationConfiguration    [4560] | Services: V | Pipeline: V

If they’re not listed, double-check your that your PipelineOptions are loading the engine plugins.