iOS Nexmo SDK call a phone number in app voice custom answer url

Question

I am following the Nexmo documentation here I cant find the iOS docs anymore (mysteriously) Specifically the docs talk about the Answer URL it says

You are expected to replace CALLEE_PHONE_NUMBER with the number to be called. But, ultimately, the number that is actually called is the one supplied in the Answer URL webhook. In a real-life use case, you would create a server component to serve as the Answer URL. The app will send to your backend, through the Answer URL the CALLEE_PHONE_NUMBER, the backend would validate it and then supply it in the JSON returned.

Note: The gist you created is specific to this tutorial. In a real-life scenario, the Answer URL should be provided by a purposely built web solution. Your backend should provide that can serve custom NCCOs and, for this case, receive and validate the phone number dialled from the app.```

So I created my custom backend that takes in a ?to parameter which returns valid json like so: GET https://mycustomurl.herokuapp.com/hello?to=18052425555

[{"action":"talk","text":"Please wait while we connect you."},{"action":"connect","timeout":20,"from":"14697938019","endpoint":{"type":"phone","number":"18052425555"}}]

I put that custom url into my application in the dashboard like this... https://mycustomurl.herokuapp.com/ I have also tried many other variations like full path /hello etc.

When I place the call from my app... how do I reference this endpoint? is the parameter automatically to (a nexmo support person told me that)? do i pass in the url?

i have tried all these combos:

client.call("https://mycustomurl.herokuapp.com/hello?to=18052428083", callHandler: .server)
client.call("hello?to=18052428083", callHandler: .server)
client.call("18052428083", callHandler: .server)

I cannot get it to work and cannot find anything in the docs about how to use the custom backend answer url. Any help would be appreciated.

Answer 1

We moved some stuff around, apologies that the redirect didn't work. Here is a step by step tutorial on making a call from the app.

Your custom url does not need any parameters, but you will need to update the dashboard to use https://mycustomurl.herokuapp.com/hello.

In the app, you call client.call("44000000000", callHandler: .server) which will make a GET request to your custom url. The request made to the custom url will have a JSON object in its query which would like like this:

{
  to: '44000000000',
  from_user: 'Alice',
  conversation_uuid: 'CON-7a15150b-121d-42b7-91eb-23ccefdcbf5e',
  uuid: 'NONE'
}

The to value in the JSON object will be the number provided in the app. You can use this to fill out the NCCO that you would return, for example:

[
    {
        "action": "talk",
        "text": "Please wait while we connect you."
    },
    {
        "action": "connect",
        "endpoint": [
            {
                "type": "phone",
                "from": request.body.from_user
                "number": request.body.to
            }
        ]
    }
]