So if I am calling this service from an Ensemble operation that looks something like this:

Method getPatient(pRequest As RESTDemo.REST.ClaimRequest, Output pResponse As EnsLib.REST.GenericMessage) As %Status
{
  try {
    // Prepare and log the call
    // Append the claim to the URL
    Set tURL=..Adapter.URL_"/claims/"_pRequest.claimBlob    
       
    // Execute the call
    set tSC=..Adapter.GetURL(tURL,.tHttpResponse)
       
    #; Suppress HTTP status errors and just pass back the status, headers and body
    If $$$ISERR(tSC)&&'$$$StatusEquals(tSC,$$$EnsErrHTTPStatus) { Quit }
       
    // Return the response      
    Set tSC=$$$OK
    If $IsObject(tHttpResponse.Data) {
      Set tStream=tHttpResponse.Data
    } Else {
      Set tStream=##class(%GlobalBinaryStream).%New()
      Set tSC=tStream.Write(tHttpResponse.Data)  Quit:$$$ISERR(tSC)
    }
    Set pResponse=##class(EnsLib.REST.GenericMessage).%New(tStream,,tHttpResponse)
    Do pResponse.HTTPHeaders.SetAt(tHttpResponse.StatusLine,"StatusLine")
  } catch {
    Set tSC=$$$SystemError
  }
  Quit tSC
}

Would I just call $system.Encryption.Base64Encode() on the claimBlob property?

I typically use the SQL shell in the terminal when doing this. It is very powerful.

SAMPLES>do $system.SQL.Shell()

SQL Command Line Shell
----------------------------------------------------

The command prefix is currently set to: <<nothing>>.
Enter q to quit, ? for help.

SAMPLES>>?

Interactive SQL Shell
               (c) InterSystems Corporation 1999-2009 All Rights Reserved
----------------------------------------------------
To execute an SQL statement, type it in and press ENTER.
To execute a multiline SQL statement, press <enter> to enter
multiline statement mode, enter the each statement line and
enter GO to exit multiline statement mode and execute the statement.

etc...

This uses %SQL.Statement to do all the work and has a number of options including saving of queries, etc.

Looks like the server definition screen no longer allows me certain characters in the connection name. I used to name my server connections like this: "Ensemble 2016.2 736". This used to work fine. Now I get no "Finish" button unless I take out the white space and possibly the period. I ended up creating the following with no issues: "Ensemble2016p2b736"