Quick example of using python and Twilio for connecting agent to customer using the VERIFIED caller id of the agent to make the call.

connectagent.py

# Download the helper library from https://www.twilio.com/docs/python/install
from twilio.rest import Client
import os
from twilio.twiml.voice_response import Dial, VoiceResponse
from flask import Flask, request

app = Flask(__name__)
# Your Account SID from twilio.com/console
account_sid = os.environ.get('TWILIO_ACCOUNT_SID')
# Your Auth Token from twilio.com/console
auth_token = os.environ.get('TWILIO_AUTH_TOKEN')
# YOUR verfied caller id
callerid = str(os.environ.get('TWILIO_MYCALLERID'))
# the number you have purchased in twilio that makes the initial call to the agent
twilio_number = str(os.environ.get('TWILIO_NUMBER')) 
# URL of where this file is hosted... {URL}/connectcustomer
twimlurl = 'http://xxxxxxxx.ngrok.io/connectcustomer' #using ngrok locally to test you will need to change this url so that when the agent is connected it calls back this program.

customer_number = '' # leave blank, just setting up var
callerid_yesno = "yes" # use verified caller id

client = Client(account_sid, auth_token)

# provides the xml Twiml to connect the customer to the agent
@app.route("/connectcustomer", methods=['GET', 'POST'])
def connect_customer():
    response = VoiceResponse()
    if callerid_yesno == "yes":
        response.dial(number=customer_number, callerId=callerid)
    else:
        response.dial(number=customer_number)
        
    print(str(response))
    return str(response)


#form main menu
@app.route('/')
def form():
    return '''
        <form action="/connect_agent" method="post">
            Agent    #: <input name="agent_number" type="text" /><br>
            Customer #: <input name="customer_number" type="text" /><br>
            Caller ID? yes/no : <input name="callerid_yesno" type="text" value="yes" /><br><br>
            <input value="Connect" type="submit" />
        </form>
    '''
    return "ok"
    
# connect agent first
@app.route("/connect_agent", methods=['POST'])
def connect_agent():
    global customer_number
    global callerid_yesno
    
    if request.method == 'POST':
    
        agent_number = request.form['agent_number']
        customer_number = request.form['customer_number']
        callerid_yesno = request.form['callerid_yesno']
        
        call = client.calls.create(
                                url=twimlurl,
                                to=agent_number,
                                from_=twilio_number
                            )
    
        print(call.sid)
        return "ok"
    
    return "not post"


if __name__ == "__main__":
    print("running")
    app.run(debug=True)