How to Build an IVR System with Python and a Voice API

An IVR (Interactive Voice Response) system is the technology behind 'Press 1 for sales, press 2 for support.' Building one used to require expensive hardware. Today, you can build a fully featured IVR with Python and a voice API in an afternoon.

What we will build

• A greeting menu with 3 department options
• Routing based on caller input
• Graceful handling of invalid input
• Call recording for quality assurance

Setup

pip install wirexaapi flask

1. Originate the call

call = client.calls.create(
    to="+15551234567",
    from_="+15559876543",
    url="https://your-backend.com/ivr",
    record=True,
)

2. Main menu

@app.route('/ivr', methods=['POST'])
def ivr_main():
    xml = '''<Response>
  <Gather numDigits="1" timeout="8" action="/ivr/route">
    <Say language="en-US" voice="polly.Joanna">
      Thank you for calling. Press 1 for Sales.
      Press 2 for Support. Press 3 for Billing.
    </Say>
  </Gather>
  <Redirect>/ivr</Redirect>
</Response>'''
    return Response(xml, mimetype='text/xml')

3. Route by digit

@app.route('/ivr/route', methods=['POST'])
def ivr_route():
    digit = request.form.get('Digits', '')
    routes = {
        '1': ('Sales', '/ivr/sales'),
        '2': ('Support', '/ivr/support'),
        '3': ('Billing', '/ivr/billing'),
    }
    if digit in routes:
        name, path = routes[digit]
        xml = f'<Response><Say>Connecting to {name}.</Say><Redirect>{path}</Redirect></Response>'
    else:
        xml = '<Response><Say>Invalid option.</Say><Redirect>/ivr</Redirect></Response>'
    return Response(xml, mimetype='text/xml')

Tips for production IVRs

• Keep menus to 4 options or fewer — callers forget longer lists
• Always offer a way to repeat and to reach a human agent
• Use short, clear Say text — avoid complex sentences
• Enable call recording from day one for QA and compliance
• Log Digits from every Gather to analyze drop-off points

Next steps

This IVR runs entirely from Python + Flask with no special hardware. You can extend it with database lookups, CRM integrations, or real-time agent transfers.

Read the full API reference or contact us to set up your account.