Getting Started with XML

Build your first voice application with Vobiz XML. This guide walks you through setting up webhooks, writing your first XML responses, and testing call flows.

Prerequisites

What You'll Need

✓A Vobiz account with API access
✓A phone number purchased from Vobiz
✓A web server that can receive HTTP requests (webhook endpoint)
✓Basic understanding of HTTP and XML

Recommended Tools

•ngrok or similar for local development tunneling
•Postman for testing webhooks
•Node.js, Python, or PHP for server-side logic
•XML validator to check syntax

Hello World Example

Let's create the simplest possible voice application: answering a call and speaking a greeting.

Step 1: Create a Webhook Endpoint

Set up a simple HTTP server that returns XML. Here's a Node.js Express example:

server.js

const express = require('express');
const app = express();

app.post('/answer', (req, res) => {
  const xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Speak>Hello! Welcome to Vobiz telephony platform.</Speak>
    <Hangup/>
</Response>`;

  res.type('application/xml');
  res.send(xml);
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Step 2: Expose Your Server

For local development, use ngrok to create a public URL:

Terminal

ngrok http 3000

ngrok will provide a URL like https://abc123.ngrok.io

Step 3: Configure Your Application

In the Vobiz console, configure your Application's Answer URL:

Answer URL: https://abc123.ngrok.io/answer
Method: POST

Assign this Application to your Vobiz phone number. When someone calls that number, they'll hear your greeting!

IVR Menu Example

Now let's build an interactive IVR menu that collects user input and routes calls accordingly.

Answer Endpoint

POST /answer - Present IVR Menu

app.post('/answer', (req, res) => {
  const xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Gather
        numDigits="1"
        timeout="10"
        action="https://abc123.ngrok.io/menu-choice"
        method="POST">
        <Speak>
            Welcome to our support line.
            Press 1 for sales, press 2 for technical support,
            or press 0 to speak with an operator.
        </Speak>
    </Gather>
    <Speak>We didn't receive your input. Goodbye!</Speak>
    <Hangup/>
</Response>`;

  res.type('application/xml');
  res.send(xml);
});

Menu Choice Handler

POST /menu-choice - Route Based on Input

app.post('/menu-choice', (req, res) => {
  const digit = req.body.Digits;
  let xml;

  switch(digit) {
    case '1':
      xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Speak>Connecting you to sales.</Speak>
    <Dial>+14155551111</Dial>
</Response>`;
      break;

    case '2':
      xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Speak>Connecting you to technical support.</Speak>
    <Dial>+14155552222</Dial>
</Response>`;
      break;

    case '0':
      xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Speak>Transferring to operator.</Speak>
    <Dial>+14155550000</Dial>
</Response>`;
      break;

    default:
      xml = `<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Speak>Invalid selection. Please try again.</Speak>
    <Redirect>https://abc123.ngrok.io/answer</Redirect>
</Response>`;
  }

  res.type('application/xml');
  res.send(xml);
});

Testing Your XML

Method 1: Real Phone Calls

The most accurate way to test is to call your Vobiz number from a real phone.

• Test audio quality and timing
• Verify DTMF input collection
• Check call transfer functionality
• Monitor webhook logs in real-time

Method 2: Webhook Simulation

Use Postman or cURL to simulate Vobiz webhook requests to your endpoint.

Test with cURL

curl -X POST https://yourapp.com/answer \
  -d "CallUUID=test123" \
  -d "From=+14155551234" \
  -d "To=+14155559999"

Development Tips

• Log all incoming webhook data to debug call flows
• Validate your XML syntax before deploying changes
• Use descriptive Speak messages to understand which code path executed
• Start simple and add complexity gradually
• Monitor server response times—keep them under 1 second

How XML Works

Best Practices