Unable to add user to app via Merge passthrough request

[tropic-josh]

I can add a user to an app through the API via Postman and the Oktakit ruby gem. When performing what should be the same request through Merge, it returns a 400. Other Merge passthrough requests are working, it’s just the POST to {{url}}/api/v1/apps/{{appId}}/users that’s not working.

Request:

payload = {
  method: "POST",
  headers: {
    Accept: "application/json",
    ContentType: "application/json"
  },
  path: "/api/v1/apps/#{@okta_app_id}/users",
  data: {
    id: @okta_user_id || "",
    scope: "USER"
  }
}
response = api_instance.passthrough_create(access_token, payload)

Response:

{:errorCode=>"E0000021",
 :errorSummary=>"Bad request.  Accept and/or Content-Type headers likely do not match supported values.",
 :errorLink=>"E0000021",
 :errorId=>"oaew11VolvfReORLaZtMdGS2A",
 :errorCauses=>[]}

It’s not the suggested issue of Accept and/or Content-Type. Here’s the request headers in the MergeHRISClient object:

 #<MergeHRISClient::RemoteResponse:0x000000010d600de8
 @headers=
  {:"User-Agent"=>"Mozilla/5.0",
   :"Accept-Encoding"=>"gzip, deflate, br",
   :Accept=>"application/json",
   :Connection=>"keep-alive",
   :Authorization=>"<redacted>",
   :ContentType=>"application/json",
   :"Content-Length"=>"47",
   :"x-datadog-trace-id"=>"15018062895474666192",
   :"x-datadog-parent-id"=>"15035386594106804400",
   :"x-datadog-sampling-priority"=>"1"},
 @method="POST",
 @path="/api/v1/apps/<app-id>/users",
  ...
>

Calling .to_json on the body has the same effect. I’ve compared working Postman requests to the Merge <=> Okta request and I don’t see any real difference.

[tropic-josh]

I’ve also tried other content types but I haven’t been able to get this call to work if it’s coming from Merge. I’ve tried the Merge API Tester and I’m getting the same error.

[tropic-josh]

Found the error. The header needs to be “Content-Type” and not “ContentType”