To view your REST services using the OpenEdge-specific JSON output format, use the following URI syntax:
host:port[/webapp_name]/server/rest/services
For example:
localhost:8810/server/rest/services
localhost:8810/mywebapp/server/rest/services
The following is sample JSON output:
{
  "RESTServices": [
    {
      "http://localhost:8810/rest/_oepingService": {
        "__oeping": {
          "OpenEdge.Rest.Admin.AppServerStatus..ServerStatus": {
            "Method": " GET",
            "Resource-Path": "/_oeping",
            "Http-Request-Type": "application/json",
            "Http-Response-Type": "application/json",
            "ABL-Resource-Name": "OpenEdge.Rest.Admin.AppServerStatus.cls",
            "ABL-Resource-path": "WRKDIR\\",
            "Procedure-Type": "Internal Function",
            "Input": [],
            "Output": [
              {
                "HTTP-Target": "http.body[json.object['response'].string['_retVal']]",
                "ABL-Source": "retVal",
                "ABL-Type": "CHARACTER"
              }
            ]
          }
        }
      }
    }
  ]
}

The output contains a single RESTServices property which consists of an array of objects representing each service available. This includes information such as the HTTP verb expected to access those services, schema information (when applicable), and a list of input and output parameters defined for each service. For parameters, the expected external (HTTP) datatype is described along with the internal (ABL) datatype.