The docs have this example:

- path: "/users"
  method: POST
  capture:
    petName:
      xPath: "/env:Envelope/env:Body/pets:animal/pets:name"
      store: testStore
      xmlNamespaces:
        env: "http://schemas.xmlsoap.org/soap/envelope/"
        pets: "urn:com:example:petstore"

But I’m getting an error

14:01:37 INFO i.g.i.Imposter - Starting mock engine 4.0.0
14:01:37 DEBUG i.g.i.c.u.ConfigUtil - Loading configuration file: .configsgm-dds-config.yaml
14:01:38 DEBUG i.g.i.c.u.ConfigUtil - Loading configuration file: .configssingle-response-config.yaml
14:01:38 DEBUG i.g.i.p.PluginManager - Loaded 5 plugin(s): [js-detector, store-detector, rest, js-graal, store-inmem]
14:01:39 ERROR i.v.c.i.l.c.VertxIsolatedDeployer - Failed in deploying verticle
java.lang.RuntimeException: Error configuring plugin: rest
at io.gatehill.imposter.plugin.PluginManagerImpl.configurePlugins(PluginManagerImpl.kt:133) ~[imposter.jar:?]
at io.gatehill.imposter.plugin.PluginManagerImpl.startPlugins(PluginManagerImpl.kt:91) ~[imposter.jar:?]
at io.gatehill.imposter.Imposter$start$1.invokeSuspend(Imposter.kt:132) ~[imposter.jar:?]
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) ~[imposter.jar:?]
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108) ~[imposter.jar:?]
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:584) ~[imposter.jar:?]
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:793) ~[imposter.jar:?]
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:697) ~[imposter.jar:?]
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:684) ~[imposter.jar:?]
Caused by: java.lang.RuntimeException: Error loading configuration file: my-config.yml , reason: Unrecognized field "xPath" (class io.gatehill.imposter.plugin.config.capture.ItemCaptureConfig), not marked as ignorable (12 known properties: "requestBody", "const", "queryParam", "pathParam", "formParam", "phase", "requestHeader", "jsonPath", "key", "store", "expression", "enabled"])

with the following config

---
plugin: rest 
basePath: "/dds"
system:
  xmlNamespaces:
    soap: "http://schemas.xmlsoap.org/soap/envelope/"
    star: "http://www.starstandard.org/STAR/5"

resources:
  - path: "/appointments"
    method: POST
    capture:
      serviceappointmentId:
        xPath: "/star:ProcessServiceAppointment/star:ProcessServiceAppointmentDataArea/star:ServiceAppointment/star:ServiceAppointmentHeader/star:SecondaryDealerNumberID"
        store: requestData
        xmlNamespaces:
          star: "http://www.starstandard.org/STAR/5"
    requestBody:
      xPath: "/star:ProcessServiceAppointment/star:ProcessServiceAppointmentDataArea"
      operator: Exists
    response:
      statusCode: 202
      content: "appt received"

Actually what I’m trying to do is capture the whole payload, but I switched it to just a single data item to as shown in the docs to see if that would work.

Note that if I leave out the capture settings, then the xPath matching works fine.