Receive a call
At the top of the ViewController class, below the client declaration, add a string property to hold a reference to any call in progress.
When the application receives a call you will want to give the option to accept or reject the call. To do this add the displayIncomingCallAlert function to the ViewController class.
The displayIncomingCallAlert function takes a call ID and a caller as a parameters. Note in the UIAlertAction for answering the invite, if successful you will assign the callID to the property from earlier
To use displayIncomingCallAlert you need to use the VGVoiceClientDelegate which has a function that will be called when the client receives an incoming VGVoiceInvite.
You can also implement the didReceiveHangupForCall delegate function which is called if the call is hung up.
NOTE: Also, please make sure that the webhook server you built in the previous steps is still running.
Press Cmd + R to build and run again, when you call the number linked with your application from earlier you will be presented with an alert. You can pick up and the call will be connected!

Webhooks
As you proceed with the call, please switch to the terminal and notice the /voice/answer endpoint being called to retrieve the NCCO:
NCCO request:
- caller: 441234567890
Also, as the call progresses through various stages, /voice/event is being sent events:
EVENT:
{
headers: {},
from: '441234567890',
to: '442038297050',
uuid: '0779a56d002f1c7f47f82ef5fe84ab79',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'ringing',
direction: 'inbound',
timestamp: '2021-03-29T21:20:05.582Z'
}
---
EVENT:
{
headers: {},
from: '441234567890',
to: '442038297050',
uuid: '0779a56d002f1c7f47f82ef5fe84ab79',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'started',
direction: 'inbound',
timestamp: '2021-03-29T21:20:05.582Z'
}
---
EVENT:
{
start_time: null,
headers: {},
rate: null,
from: '441234567890',
to: '442038297050',
uuid: '0779a56d002f1c7f47f82ef5fe84ab79',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'answered',
direction: 'inbound',
network: null,
timestamp: '2021-03-29T21:20:06.182Z'
}
---
EVENT:
{
from: '441234567890',
to: 'Alice',
uuid: '944bf4bf-8dc7-4e23-86b2-2f4234777416',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'started',
direction: 'outbound',
timestamp: '2021-03-29T21:20:13.025Z'
}
---
EVENT:
{
start_time: null,
headers: {},
rate: null,
from: '441234567890',
to: 'Alice',
uuid: '944bf4bf-8dc7-4e23-86b2-2f4234777416',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'answered',
direction: 'outbound',
network: null,
timestamp: '2021-03-29T21:20:13.025Z'
}
---
EVENT:
{
headers: {},
end_time: '2021-03-29T21:20:16.000Z',
uuid: '944bf4bf-8dc7-4e23-86b2-2f4234777416',
network: null,
duration: '5',
start_time: '2021-03-29T21:20:11.000Z',
rate: '0.00',
price: '0',
from: '441234567890',
to: 'Alice',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'completed',
direction: 'outbound',
timestamp: '2021-03-29T21:20:17.574Z'
}
---
EVENT:
{
headers: {},
end_time: '2021-03-29T21:20:18.000Z',
uuid: '0779a56d002f1c7f47f82ef5fe84ab79',
network: 'GB-FIXED',
duration: '12',
start_time: '2021-03-29T21:20:06.000Z',
rate: '0.00720000',
price: '0.00144000',
from: ' 441234567890',
to: '442038297050',
conversation_uuid: 'CON-8f5a100c-fbce-4218-8d4b-16341335bcd6',
status: 'completed',
direction: 'inbound',
timestamp: '2021-03-29T21:20:17.514Z'
}
---
Receiving a phone call in-app
You receive a call from a phone to your app