Masked Phone Numbers with Python and Flask

This Flask sample application is modeled after the rental experience created by AirBnB but with more Klingons.

Host users can offer rental properties which other guest users can reserve. The guest and the host can then anonymously communicate via a disposable Twilio phone number created just for a reservation. In this tutorial, we'll show you the key bits of code to make this work.

To run this sample app yourself, download the code and follow the instructions on GitHub.

(warning)

Legal implications of managing communications between users

If you choose to manage communications between your users, including voice calls, text-based messages (e.g., SMS), and chat, you may need to comply with certain laws and regulations, including those regarding obtaining consent. Additional information regarding legal compliance considerations and best practices for using Twilio to manage and record communications between your users, such as when using Twilio Proxy, can be found here.

Notice: Twilio recommends that you consult with your legal counsel to make sure that you are complying with all applicable laws in connection with communications you record or store using Twilio.

Read how Lyft uses masked phone numbers to let customers securely contact drivers.

Create a Reservation

The first step in connecting a guest and a host is creating a reservation.

We handle here a submission form for a new reservation. After we save the reservation to the database, we send the host an SMS message asking them to accept or reject the reservation.

Create A New Reservation

1from twilio.twiml.messaging_response import MessagingResponse
2from twilio.twiml.voice_response import VoiceResponse
3
4from airtng_flask import db, bcrypt, app, login_manager
5from flask import g, request
6from flask.ext.login import login_user, logout_user, current_user, login_required
7
8from airtng_flask.forms import RegisterForm, LoginForm, VacationPropertyForm, ReservationForm, \
9    ReservationConfirmationForm, ExchangeForm
10from airtng_flask.view_helpers import twiml, view, redirect_to, view_with_params
11from airtng_flask.models import init_models_module
12
13init_models_module(db, bcrypt, app)
14
15from airtng_flask.models.user import User
16from airtng_flask.models.vacation_property import VacationProperty
17from airtng_flask.models.reservation import Reservation
18
19
20@app.route('/', methods=["GET", "POST"])
21@app.route('/register', methods=["GET", "POST"])
22def register():
23    form = RegisterForm()
24    if request.method == 'POST':
25        if form.validate_on_submit():
26
27            if User.query.filter(User.email == form.email.data).count() > 0:
28                form.email.errors.append("Email address already in use.")
29                return view('register', form)
30
31            user = User(
32                    name=form.name.data,
33                    email=form.email.data,
34                    password=form.password.data,
35                    phone_number="+{0}{1}".format(form.country_code.data, form.phone_number.data),
36                    area_code=str(form.phone_number.data)[0:3])
37
38            db.session.add(user)
39            db.session.commit()
40            login_user(user, remember=True)
41
42            return redirect_to('home')
43        else:
44            return view('register', form)
45
46    return view('register', form)
47
48
49@app.route('/login', methods=["GET", "POST"])
50def login():
51    form = LoginForm()
52    if request.method == 'POST':
53        if form.validate_on_submit():
54            candidate_user = User.query.filter(User.email == form.email.data).first()
55
56            if candidate_user is None or not bcrypt.check_password_hash(candidate_user.password,
57                                                                        form.password.data):
58                form.password.errors.append("Invalid credentials.")
59                return view('login', form)
60
61            login_user(candidate_user, remember=True)
62            return redirect_to('home')
63    return view('login', form)
64
65
66@app.route('/logout', methods=["POST"])
67@login_required
68def logout():
69    logout_user()
70    return redirect_to('home')
71
72
73@app.route('/home', methods=["GET"])
74@login_required
75def home():
76    return view('home')
77
78
79@app.route('/properties', methods=["GET"])
80@login_required
81def properties():
82    vacation_properties = VacationProperty.query.all()
83    return view_with_params('properties', vacation_properties=vacation_properties)
84
85
86@app.route('/properties/new', methods=["GET", "POST"])
87@login_required
88def new_property():
89    form = VacationPropertyForm()
90    if request.method == 'POST':
91        if form.validate_on_submit():
92            host = User.query.get(current_user.get_id())
93
94            property = VacationProperty(form.description.data, form.image_url.data, host)
95            db.session.add(property)
96            db.session.commit()
97            return redirect_to('properties')
98
99    return view('property_new', form)
100
101
102@app.route('/reservations/', methods=["POST"], defaults={'property_id': None})
103@app.route('/reservations/<property_id>', methods=["GET", "POST"])
104@login_required
105def new_reservation(property_id):
106    vacation_property = None
107    form = ReservationForm()
108    form.property_id.data = property_id
109
110    if request.method == 'POST':
111        if form.validate_on_submit():
112            guest = User.query.get(current_user.get_id())
113
114            vacation_property = VacationProperty.query.get(form.property_id.data)
115            reservation = Reservation(form.message.data, vacation_property, guest)
116            db.session.add(reservation)
117            db.session.commit()
118
119            reservation.notify_host()
120
121            return redirect_to('properties')
122
123    if property_id is not None:
124        vacation_property = VacationProperty.query.get(property_id)
125
126    return view_with_params('reservation', vacation_property=vacation_property, form=form)
127
128
129@app.route('/reservations', methods=["GET"])
130@login_required
131def reservations():
132    user = User.query.get(current_user.get_id())
133
134    reservations_as_host = Reservation.query \
135        .filter(VacationProperty.host_id == current_user.get_id() and len(VacationProperty.reservations) > 0) \
136        .join(VacationProperty) \
137        .filter(Reservation.vacation_property_id == VacationProperty.id) \
138        .all()
139
140    reservations_as_guest = user.reservations
141
142    return view_with_params('reservations',
143                            reservations_as_guest=reservations_as_guest,
144                            reservations_as_host=reservations_as_host)
145
146
147@app.route('/reservations/confirm', methods=["POST"])
148def confirm_reservation():
149    form = ReservationConfirmationForm()
150    sms_response_text = "Sorry, it looks like you don't have any reservations to respond to."
151
152    user = User.query.filter(User.phone_number == form.From.data).first()
153    reservation = Reservation \
154        .query \
155        .filter(Reservation.status == 'pending'
156                and Reservation.vacation_property.host.id == user.id) \
157        .first()
158
159    if reservation is not None:
160
161        if 'yes' in form.Body.data or 'accept' in form.Body.data:
162            reservation.confirm()
163            reservation.buy_number(user.area_code)
164        else:
165            reservation.reject()
166
167        db.session.commit()
168
169        sms_response_text = "You have successfully {0} the reservation".format(reservation.status)
170        reservation.notify_guest()
171
172    return twiml(_respond_message(sms_response_text))
173
174
175@app.route('/exchange/sms', methods=["POST"])
176def exchange_sms():
177    form = ExchangeForm()
178
179    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
180
181    response = MessagingResponse()
182    response.message(form.Body.data, to=outgoing_number)
183    return twiml(response)
184
185
186@app.route('/exchange/voice', methods=["POST"])
187def exchange_voice():
188    form = ExchangeForm()
189    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
190
191    response = VoiceResponse()
192    response.play("http://howtodocs.s3.amazonaws.com/howdy-tng.mp3")
193    response.dial(outgoing_number)
194    return twiml(response)
195
196
197# controller utils
198@app.before_request
199def before_request():
200    g.user = current_user
201    uri_pattern = request.url_rule
202    if current_user.is_authenticated and (
203                        uri_pattern == '/' or uri_pattern == '/login' or uri_pattern == '/register'):
204        redirect_to('home')
205
206
207@login_manager.user_loader
208def load_user(id):
209    try:
210        return User.query.get(id)
211    except:
212        return None
213
214
215def _gather_outgoing_phone_number(incoming_phone_number, anonymous_phone_number):
216    reservation = Reservation.query \
217        .filter(Reservation.anonymous_phone_number == anonymous_phone_number) \
218        .first()
219
220    if reservation is None:
221        raise Exception('Reservation not found for {0}'.format(incoming_phone_number))
222
223    if reservation.guest.phone_number == incoming_phone_number:
224        return reservation.vacation_property.host.phone_number
225
226    return reservation.guest.phone_number
227
228
229def _respond_message(message):
230    response = MessagingResponse()
231    response.message(message)
232    return response

Part of our reservation system is receiving reservation requests from potential renters. However, these reservations need to be confirmed. Let's see how we would handle this step.

Confirm the Reservation

Before the reservation is finalized, the host needs to confirm that the property was reserved. Learn how to automate this process on our first AirTNG tutorial Workflow Automation.

Confirm the Reservation

1from twilio.twiml.messaging_response import MessagingResponse
2from twilio.twiml.voice_response import VoiceResponse
3
4from airtng_flask import db, bcrypt, app, login_manager
5from flask import g, request
6from flask.ext.login import login_user, logout_user, current_user, login_required
7
8from airtng_flask.forms import RegisterForm, LoginForm, VacationPropertyForm, ReservationForm, \
9    ReservationConfirmationForm, ExchangeForm
10from airtng_flask.view_helpers import twiml, view, redirect_to, view_with_params
11from airtng_flask.models import init_models_module
12
13init_models_module(db, bcrypt, app)
14
15from airtng_flask.models.user import User
16from airtng_flask.models.vacation_property import VacationProperty
17from airtng_flask.models.reservation import Reservation
18
19
20@app.route('/', methods=["GET", "POST"])
21@app.route('/register', methods=["GET", "POST"])
22def register():
23    form = RegisterForm()
24    if request.method == 'POST':
25        if form.validate_on_submit():
26
27            if User.query.filter(User.email == form.email.data).count() > 0:
28                form.email.errors.append("Email address already in use.")
29                return view('register', form)
30
31            user = User(
32                    name=form.name.data,
33                    email=form.email.data,
34                    password=form.password.data,
35                    phone_number="+{0}{1}".format(form.country_code.data, form.phone_number.data),
36                    area_code=str(form.phone_number.data)[0:3])
37
38            db.session.add(user)
39            db.session.commit()
40            login_user(user, remember=True)
41
42            return redirect_to('home')
43        else:
44            return view('register', form)
45
46    return view('register', form)
47
48
49@app.route('/login', methods=["GET", "POST"])
50def login():
51    form = LoginForm()
52    if request.method == 'POST':
53        if form.validate_on_submit():
54            candidate_user = User.query.filter(User.email == form.email.data).first()
55
56            if candidate_user is None or not bcrypt.check_password_hash(candidate_user.password,
57                                                                        form.password.data):
58                form.password.errors.append("Invalid credentials.")
59                return view('login', form)
60
61            login_user(candidate_user, remember=True)
62            return redirect_to('home')
63    return view('login', form)
64
65
66@app.route('/logout', methods=["POST"])
67@login_required
68def logout():
69    logout_user()
70    return redirect_to('home')
71
72
73@app.route('/home', methods=["GET"])
74@login_required
75def home():
76    return view('home')
77
78
79@app.route('/properties', methods=["GET"])
80@login_required
81def properties():
82    vacation_properties = VacationProperty.query.all()
83    return view_with_params('properties', vacation_properties=vacation_properties)
84
85
86@app.route('/properties/new', methods=["GET", "POST"])
87@login_required
88def new_property():
89    form = VacationPropertyForm()
90    if request.method == 'POST':
91        if form.validate_on_submit():
92            host = User.query.get(current_user.get_id())
93
94            property = VacationProperty(form.description.data, form.image_url.data, host)
95            db.session.add(property)
96            db.session.commit()
97            return redirect_to('properties')
98
99    return view('property_new', form)
100
101
102@app.route('/reservations/', methods=["POST"], defaults={'property_id': None})
103@app.route('/reservations/<property_id>', methods=["GET", "POST"])
104@login_required
105def new_reservation(property_id):
106    vacation_property = None
107    form = ReservationForm()
108    form.property_id.data = property_id
109
110    if request.method == 'POST':
111        if form.validate_on_submit():
112            guest = User.query.get(current_user.get_id())
113
114            vacation_property = VacationProperty.query.get(form.property_id.data)
115            reservation = Reservation(form.message.data, vacation_property, guest)
116            db.session.add(reservation)
117            db.session.commit()
118
119            reservation.notify_host()
120
121            return redirect_to('properties')
122
123    if property_id is not None:
124        vacation_property = VacationProperty.query.get(property_id)
125
126    return view_with_params('reservation', vacation_property=vacation_property, form=form)
127
128
129@app.route('/reservations', methods=["GET"])
130@login_required
131def reservations():
132    user = User.query.get(current_user.get_id())
133
134    reservations_as_host = Reservation.query \
135        .filter(VacationProperty.host_id == current_user.get_id() and len(VacationProperty.reservations) > 0) \
136        .join(VacationProperty) \
137        .filter(Reservation.vacation_property_id == VacationProperty.id) \
138        .all()
139
140    reservations_as_guest = user.reservations
141
142    return view_with_params('reservations',
143                            reservations_as_guest=reservations_as_guest,
144                            reservations_as_host=reservations_as_host)
145
146
147@app.route('/reservations/confirm', methods=["POST"])
148def confirm_reservation():
149    form = ReservationConfirmationForm()
150    sms_response_text = "Sorry, it looks like you don't have any reservations to respond to."
151
152    user = User.query.filter(User.phone_number == form.From.data).first()
153    reservation = Reservation \
154        .query \
155        .filter(Reservation.status == 'pending'
156                and Reservation.vacation_property.host.id == user.id) \
157        .first()
158
159    if reservation is not None:
160
161        if 'yes' in form.Body.data or 'accept' in form.Body.data:
162            reservation.confirm()
163            reservation.buy_number(user.area_code)
164        else:
165            reservation.reject()
166
167        db.session.commit()
168
169        sms_response_text = "You have successfully {0} the reservation".format(reservation.status)
170        reservation.notify_guest()
171
172    return twiml(_respond_message(sms_response_text))
173
174
175@app.route('/exchange/sms', methods=["POST"])
176def exchange_sms():
177    form = ExchangeForm()
178
179    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
180
181    response = MessagingResponse()
182    response.message(form.Body.data, to=outgoing_number)
183    return twiml(response)
184
185
186@app.route('/exchange/voice', methods=["POST"])
187def exchange_voice():
188    form = ExchangeForm()
189    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
190
191    response = VoiceResponse()
192    response.play("http://howtodocs.s3.amazonaws.com/howdy-tng.mp3")
193    response.dial(outgoing_number)
194    return twiml(response)
195
196
197# controller utils
198@app.before_request
199def before_request():
200    g.user = current_user
201    uri_pattern = request.url_rule
202    if current_user.is_authenticated and (
203                        uri_pattern == '/' or uri_pattern == '/login' or uri_pattern == '/register'):
204        redirect_to('home')
205
206
207@login_manager.user_loader
208def load_user(id):
209    try:
210        return User.query.get(id)
211    except:
212        return None
213
214
215def _gather_outgoing_phone_number(incoming_phone_number, anonymous_phone_number):
216    reservation = Reservation.query \
217        .filter(Reservation.anonymous_phone_number == anonymous_phone_number) \
218        .first()
219
220    if reservation is None:
221        raise Exception('Reservation not found for {0}'.format(incoming_phone_number))
222
223    if reservation.guest.phone_number == incoming_phone_number:
224        return reservation.vacation_property.host.phone_number
225
226    return reservation.guest.phone_number
227
228
229def _respond_message(message):
230    response = MessagingResponse()
231    response.message(message)
232    return response

Once the reservation is confirmed, we need to purchase a Twilio number that the guest and host can use to communicate.

Purchase a Twilio Number

Here we use the Twilio Python helper library to search for and buy a new phone number to associate with the reservation. We start by searching for a number with a local area code - if we can't find one, we take any available phone number in that country.

When we buy the number, we designate a TwiML Application that will handle webhook requests when the new number receives an incoming call or text.

We then save the new phone number on our Reservation model. Therefore when our app receives calls or messages to this number we know which reservation the call or text belongs to.

Purchase a Twilio Number

airtng_flask/models/reservation.py

1from airtng_flask.models import app_db, auth_token, account_sid, phone_number, application_sid
2from flask import render_template
3from twilio.rest import Client
4
5DB = app_db()
6
7
8class Reservation(DB.Model):
9    __tablename__ = "reservations"
10
11    id = DB.Column(DB.Integer, primary_key=True)
12    message = DB.Column(DB.String, nullable=False)
13    status = DB.Column(DB.Enum('pending', 'confirmed', 'rejected', name='reservation_status_enum'),
14                       default='pending')
15    anonymous_phone_number = DB.Column(DB.String, nullable=True)
16    guest_id = DB.Column(DB.Integer, DB.ForeignKey('users.id'))
17    vacation_property_id = DB.Column(DB.Integer, DB.ForeignKey('vacation_properties.id'))
18    guest = DB.relationship("User", back_populates="reservations")
19    vacation_property = DB.relationship("VacationProperty", back_populates="reservations")
20
21    def __init__(self, message, vacation_property, guest):
22        self.message = message
23        self.guest = guest
24        self.vacation_property = vacation_property
25        self.status = 'pending'
26
27    def confirm(self):
28        self.status = 'confirmed'
29
30    def reject(self):
31        self.status = 'rejected'
32
33    def __repr__(self):
34        return '<Reservation {0}>'.format(self.id)
35
36    def notify_host(self):
37        self._send_message(self.vacation_property.host.phone_number,
38                           render_template('messages/sms_host.txt',
39                                           name=self.guest.name,
40                                           description=self.vacation_property.description,
41                                           message=self.message))
42
43    def notify_guest(self):
44        self._send_message(self.guest.phone_number,
45                           render_template('messages/sms_guest.txt',
46                                           description=self.vacation_property.description,
47                                           status=self.status))
48
49    def buy_number(self, area_code):
50        numbers = self._get_twilio_client().available_phone_numbers("US") \
51                                           .local \
52                                           .list(area_code=area_code,
53                                                 sms_enabled=True,
54                                                 voice_enabled=True)
55
56        if numbers:
57            number = self._purchase_number(numbers[0])
58            self.anonymous_phone_number = number
59            return number
60        else:
61            numbers = self._get_twilio_client().available_phone_numbers("US") \
62                                               .local \
63                                               .list(sms_enabled=True, voice_enabled=True)
64
65            if numbers:
66                number = self._purchase_number(numbers[0])
67                self.anonymous_phone_number = number
68                return number
69
70        return None
71
72    def _purchase_number(self, number):
73        return self._get_twilio_client().incoming_phone_numbers \
74                                        .create(sms_application_sid=application_sid(),
75                                                voice_application_sid=application_sid(),
76                                                phone_number=number) \
77                                        .phone_number
78
79    def _get_twilio_client(self):
80        return Client(account_sid(), auth_token())
81
82    def _send_message(self, to, message):
83        self._get_twilio_client().messages \
84                                 .create(to,
85                                         from_=phone_number(),
86                                         body=message)

Now that each reservation has a Twilio Phone Number, we can see how the application will look up reservations as guest or host calls come in.

Find a Reservation

When someone messages or calls one of the Twilio numbers (that we purchased for a reservation) Twilio makes a request to the URL you set in the TwiML app. That request will contain some helpful metadata:

The incoming_phone_number number that originally called or sent an SMS.
The anonymous_phone_number Twilio number that triggered this request.

Take a look at Twilio's SMS Documentation and Twilio's Voice Documentation for a full list of the parameters you can use.

In our code we use the To parameter sent by Twilio to find a reservation that has the number we bought stored in it, as this is the number both hosts and guests will call and send SMSs to.

Find a Reservation

1from twilio.twiml.messaging_response import MessagingResponse
2from twilio.twiml.voice_response import VoiceResponse
3
4from airtng_flask import db, bcrypt, app, login_manager
5from flask import g, request
6from flask.ext.login import login_user, logout_user, current_user, login_required
7
8from airtng_flask.forms import RegisterForm, LoginForm, VacationPropertyForm, ReservationForm, \
9    ReservationConfirmationForm, ExchangeForm
10from airtng_flask.view_helpers import twiml, view, redirect_to, view_with_params
11from airtng_flask.models import init_models_module
12
13init_models_module(db, bcrypt, app)
14
15from airtng_flask.models.user import User
16from airtng_flask.models.vacation_property import VacationProperty
17from airtng_flask.models.reservation import Reservation
18
19
20@app.route('/', methods=["GET", "POST"])
21@app.route('/register', methods=["GET", "POST"])
22def register():
23    form = RegisterForm()
24    if request.method == 'POST':
25        if form.validate_on_submit():
26
27            if User.query.filter(User.email == form.email.data).count() > 0:
28                form.email.errors.append("Email address already in use.")
29                return view('register', form)
30
31            user = User(
32                    name=form.name.data,
33                    email=form.email.data,
34                    password=form.password.data,
35                    phone_number="+{0}{1}".format(form.country_code.data, form.phone_number.data),
36                    area_code=str(form.phone_number.data)[0:3])
37
38            db.session.add(user)
39            db.session.commit()
40            login_user(user, remember=True)
41
42            return redirect_to('home')
43        else:
44            return view('register', form)
45
46    return view('register', form)
47
48
49@app.route('/login', methods=["GET", "POST"])
50def login():
51    form = LoginForm()
52    if request.method == 'POST':
53        if form.validate_on_submit():
54            candidate_user = User.query.filter(User.email == form.email.data).first()
55
56            if candidate_user is None or not bcrypt.check_password_hash(candidate_user.password,
57                                                                        form.password.data):
58                form.password.errors.append("Invalid credentials.")
59                return view('login', form)
60
61            login_user(candidate_user, remember=True)
62            return redirect_to('home')
63    return view('login', form)
64
65
66@app.route('/logout', methods=["POST"])
67@login_required
68def logout():
69    logout_user()
70    return redirect_to('home')
71
72
73@app.route('/home', methods=["GET"])
74@login_required
75def home():
76    return view('home')
77
78
79@app.route('/properties', methods=["GET"])
80@login_required
81def properties():
82    vacation_properties = VacationProperty.query.all()
83    return view_with_params('properties', vacation_properties=vacation_properties)
84
85
86@app.route('/properties/new', methods=["GET", "POST"])
87@login_required
88def new_property():
89    form = VacationPropertyForm()
90    if request.method == 'POST':
91        if form.validate_on_submit():
92            host = User.query.get(current_user.get_id())
93
94            property = VacationProperty(form.description.data, form.image_url.data, host)
95            db.session.add(property)
96            db.session.commit()
97            return redirect_to('properties')
98
99    return view('property_new', form)
100
101
102@app.route('/reservations/', methods=["POST"], defaults={'property_id': None})
103@app.route('/reservations/<property_id>', methods=["GET", "POST"])
104@login_required
105def new_reservation(property_id):
106    vacation_property = None
107    form = ReservationForm()
108    form.property_id.data = property_id
109
110    if request.method == 'POST':
111        if form.validate_on_submit():
112            guest = User.query.get(current_user.get_id())
113
114            vacation_property = VacationProperty.query.get(form.property_id.data)
115            reservation = Reservation(form.message.data, vacation_property, guest)
116            db.session.add(reservation)
117            db.session.commit()
118
119            reservation.notify_host()
120
121            return redirect_to('properties')
122
123    if property_id is not None:
124        vacation_property = VacationProperty.query.get(property_id)
125
126    return view_with_params('reservation', vacation_property=vacation_property, form=form)
127
128
129@app.route('/reservations', methods=["GET"])
130@login_required
131def reservations():
132    user = User.query.get(current_user.get_id())
133
134    reservations_as_host = Reservation.query \
135        .filter(VacationProperty.host_id == current_user.get_id() and len(VacationProperty.reservations) > 0) \
136        .join(VacationProperty) \
137        .filter(Reservation.vacation_property_id == VacationProperty.id) \
138        .all()
139
140    reservations_as_guest = user.reservations
141
142    return view_with_params('reservations',
143                            reservations_as_guest=reservations_as_guest,
144                            reservations_as_host=reservations_as_host)
145
146
147@app.route('/reservations/confirm', methods=["POST"])
148def confirm_reservation():
149    form = ReservationConfirmationForm()
150    sms_response_text = "Sorry, it looks like you don't have any reservations to respond to."
151
152    user = User.query.filter(User.phone_number == form.From.data).first()
153    reservation = Reservation \
154        .query \
155        .filter(Reservation.status == 'pending'
156                and Reservation.vacation_property.host.id == user.id) \
157        .first()
158
159    if reservation is not None:
160
161        if 'yes' in form.Body.data or 'accept' in form.Body.data:
162            reservation.confirm()
163            reservation.buy_number(user.area_code)
164        else:
165            reservation.reject()
166
167        db.session.commit()
168
169        sms_response_text = "You have successfully {0} the reservation".format(reservation.status)
170        reservation.notify_guest()
171
172    return twiml(_respond_message(sms_response_text))
173
174
175@app.route('/exchange/sms', methods=["POST"])
176def exchange_sms():
177    form = ExchangeForm()
178
179    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
180
181    response = MessagingResponse()
182    response.message(form.Body.data, to=outgoing_number)
183    return twiml(response)
184
185
186@app.route('/exchange/voice', methods=["POST"])
187def exchange_voice():
188    form = ExchangeForm()
189    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
190
191    response = VoiceResponse()
192    response.play("http://howtodocs.s3.amazonaws.com/howdy-tng.mp3")
193    response.dial(outgoing_number)
194    return twiml(response)
195
196
197# controller utils
198@app.before_request
199def before_request():
200    g.user = current_user
201    uri_pattern = request.url_rule
202    if current_user.is_authenticated and (
203                        uri_pattern == '/' or uri_pattern == '/login' or uri_pattern == '/register'):
204        redirect_to('home')
205
206
207@login_manager.user_loader
208def load_user(id):
209    try:
210        return User.query.get(id)
211    except:
212        return None
213
214
215def _gather_outgoing_phone_number(incoming_phone_number, anonymous_phone_number):
216    reservation = Reservation.query \
217        .filter(Reservation.anonymous_phone_number == anonymous_phone_number) \
218        .first()
219
220    if reservation is None:
221        raise Exception('Reservation not found for {0}'.format(incoming_phone_number))
222
223    if reservation.guest.phone_number == incoming_phone_number:
224        return reservation.vacation_property.host.phone_number
225
226    return reservation.guest.phone_number
227
228
229def _respond_message(message):
230    response = MessagingResponse()
231    response.message(message)
232    return response

Next, let's see how to connect the guest and the host via SMS.

Connect Via SMS

Our TwiML application should be configured to send HTTP requests to this controller method on any incoming text message. Our app responds with TwiML to tell Twilio what to do in response to the message.

If the initial message sent to the anonymous number was sent by the host, we forward it on to the guest. Likewise, if the original message was sent by the guest, we forward it to the host.

We wrote a helper function called gather_outgoing_phone_number to help us determine which party to forward the message to.

Connect Via SMS

1from twilio.twiml.messaging_response import MessagingResponse
2from twilio.twiml.voice_response import VoiceResponse
3
4from airtng_flask import db, bcrypt, app, login_manager
5from flask import g, request
6from flask.ext.login import login_user, logout_user, current_user, login_required
7
8from airtng_flask.forms import RegisterForm, LoginForm, VacationPropertyForm, ReservationForm, \
9    ReservationConfirmationForm, ExchangeForm
10from airtng_flask.view_helpers import twiml, view, redirect_to, view_with_params
11from airtng_flask.models import init_models_module
12
13init_models_module(db, bcrypt, app)
14
15from airtng_flask.models.user import User
16from airtng_flask.models.vacation_property import VacationProperty
17from airtng_flask.models.reservation import Reservation
18
19
20@app.route('/', methods=["GET", "POST"])
21@app.route('/register', methods=["GET", "POST"])
22def register():
23    form = RegisterForm()
24    if request.method == 'POST':
25        if form.validate_on_submit():
26
27            if User.query.filter(User.email == form.email.data).count() > 0:
28                form.email.errors.append("Email address already in use.")
29                return view('register', form)
30
31            user = User(
32                    name=form.name.data,
33                    email=form.email.data,
34                    password=form.password.data,
35                    phone_number="+{0}{1}".format(form.country_code.data, form.phone_number.data),
36                    area_code=str(form.phone_number.data)[0:3])
37
38            db.session.add(user)
39            db.session.commit()
40            login_user(user, remember=True)
41
42            return redirect_to('home')
43        else:
44            return view('register', form)
45
46    return view('register', form)
47
48
49@app.route('/login', methods=["GET", "POST"])
50def login():
51    form = LoginForm()
52    if request.method == 'POST':
53        if form.validate_on_submit():
54            candidate_user = User.query.filter(User.email == form.email.data).first()
55
56            if candidate_user is None or not bcrypt.check_password_hash(candidate_user.password,
57                                                                        form.password.data):
58                form.password.errors.append("Invalid credentials.")
59                return view('login', form)
60
61            login_user(candidate_user, remember=True)
62            return redirect_to('home')
63    return view('login', form)
64
65
66@app.route('/logout', methods=["POST"])
67@login_required
68def logout():
69    logout_user()
70    return redirect_to('home')
71
72
73@app.route('/home', methods=["GET"])
74@login_required
75def home():
76    return view('home')
77
78
79@app.route('/properties', methods=["GET"])
80@login_required
81def properties():
82    vacation_properties = VacationProperty.query.all()
83    return view_with_params('properties', vacation_properties=vacation_properties)
84
85
86@app.route('/properties/new', methods=["GET", "POST"])
87@login_required
88def new_property():
89    form = VacationPropertyForm()
90    if request.method == 'POST':
91        if form.validate_on_submit():
92            host = User.query.get(current_user.get_id())
93
94            property = VacationProperty(form.description.data, form.image_url.data, host)
95            db.session.add(property)
96            db.session.commit()
97            return redirect_to('properties')
98
99    return view('property_new', form)
100
101
102@app.route('/reservations/', methods=["POST"], defaults={'property_id': None})
103@app.route('/reservations/<property_id>', methods=["GET", "POST"])
104@login_required
105def new_reservation(property_id):
106    vacation_property = None
107    form = ReservationForm()
108    form.property_id.data = property_id
109
110    if request.method == 'POST':
111        if form.validate_on_submit():
112            guest = User.query.get(current_user.get_id())
113
114            vacation_property = VacationProperty.query.get(form.property_id.data)
115            reservation = Reservation(form.message.data, vacation_property, guest)
116            db.session.add(reservation)
117            db.session.commit()
118
119            reservation.notify_host()
120
121            return redirect_to('properties')
122
123    if property_id is not None:
124        vacation_property = VacationProperty.query.get(property_id)
125
126    return view_with_params('reservation', vacation_property=vacation_property, form=form)
127
128
129@app.route('/reservations', methods=["GET"])
130@login_required
131def reservations():
132    user = User.query.get(current_user.get_id())
133
134    reservations_as_host = Reservation.query \
135        .filter(VacationProperty.host_id == current_user.get_id() and len(VacationProperty.reservations) > 0) \
136        .join(VacationProperty) \
137        .filter(Reservation.vacation_property_id == VacationProperty.id) \
138        .all()
139
140    reservations_as_guest = user.reservations
141
142    return view_with_params('reservations',
143                            reservations_as_guest=reservations_as_guest,
144                            reservations_as_host=reservations_as_host)
145
146
147@app.route('/reservations/confirm', methods=["POST"])
148def confirm_reservation():
149    form = ReservationConfirmationForm()
150    sms_response_text = "Sorry, it looks like you don't have any reservations to respond to."
151
152    user = User.query.filter(User.phone_number == form.From.data).first()
153    reservation = Reservation \
154        .query \
155        .filter(Reservation.status == 'pending'
156                and Reservation.vacation_property.host.id == user.id) \
157        .first()
158
159    if reservation is not None:
160
161        if 'yes' in form.Body.data or 'accept' in form.Body.data:
162            reservation.confirm()
163            reservation.buy_number(user.area_code)
164        else:
165            reservation.reject()
166
167        db.session.commit()
168
169        sms_response_text = "You have successfully {0} the reservation".format(reservation.status)
170        reservation.notify_guest()
171
172    return twiml(_respond_message(sms_response_text))
173
174
175@app.route('/exchange/sms', methods=["POST"])
176def exchange_sms():
177    form = ExchangeForm()
178
179    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
180
181    response = MessagingResponse()
182    response.message(form.Body.data, to=outgoing_number)
183    return twiml(response)
184
185
186@app.route('/exchange/voice', methods=["POST"])
187def exchange_voice():
188    form = ExchangeForm()
189    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
190
191    response = VoiceResponse()
192    response.play("http://howtodocs.s3.amazonaws.com/howdy-tng.mp3")
193    response.dial(outgoing_number)
194    return twiml(response)
195
196
197# controller utils
198@app.before_request
199def before_request():
200    g.user = current_user
201    uri_pattern = request.url_rule
202    if current_user.is_authenticated and (
203                        uri_pattern == '/' or uri_pattern == '/login' or uri_pattern == '/register'):
204        redirect_to('home')
205
206
207@login_manager.user_loader
208def load_user(id):
209    try:
210        return User.query.get(id)
211    except:
212        return None
213
214
215def _gather_outgoing_phone_number(incoming_phone_number, anonymous_phone_number):
216    reservation = Reservation.query \
217        .filter(Reservation.anonymous_phone_number == anonymous_phone_number) \
218        .first()
219
220    if reservation is None:
221        raise Exception('Reservation not found for {0}'.format(incoming_phone_number))
222
223    if reservation.guest.phone_number == incoming_phone_number:
224        return reservation.vacation_property.host.phone_number
225
226    return reservation.guest.phone_number
227
228
229def _respond_message(message):
230    response = MessagingResponse()
231    response.message(message)
232    return response

Let's see how to connect the guest and the host via phone call next.

Connect Via Phone Call

Our Twilio application will send HTTP requests to this method on any incoming voice call. Our app responds with TwiML instructions that tell Twilio to Play an introductory MP3 audio file and then Dial either the guest or host, depending on who initiated the call.

Connect Via Phone Call

1from twilio.twiml.messaging_response import MessagingResponse
2from twilio.twiml.voice_response import VoiceResponse
3
4from airtng_flask import db, bcrypt, app, login_manager
5from flask import g, request
6from flask.ext.login import login_user, logout_user, current_user, login_required
7
8from airtng_flask.forms import RegisterForm, LoginForm, VacationPropertyForm, ReservationForm, \
9    ReservationConfirmationForm, ExchangeForm
10from airtng_flask.view_helpers import twiml, view, redirect_to, view_with_params
11from airtng_flask.models import init_models_module
12
13init_models_module(db, bcrypt, app)
14
15from airtng_flask.models.user import User
16from airtng_flask.models.vacation_property import VacationProperty
17from airtng_flask.models.reservation import Reservation
18
19
20@app.route('/', methods=["GET", "POST"])
21@app.route('/register', methods=["GET", "POST"])
22def register():
23    form = RegisterForm()
24    if request.method == 'POST':
25        if form.validate_on_submit():
26
27            if User.query.filter(User.email == form.email.data).count() > 0:
28                form.email.errors.append("Email address already in use.")
29                return view('register', form)
30
31            user = User(
32                    name=form.name.data,
33                    email=form.email.data,
34                    password=form.password.data,
35                    phone_number="+{0}{1}".format(form.country_code.data, form.phone_number.data),
36                    area_code=str(form.phone_number.data)[0:3])
37
38            db.session.add(user)
39            db.session.commit()
40            login_user(user, remember=True)
41
42            return redirect_to('home')
43        else:
44            return view('register', form)
45
46    return view('register', form)
47
48
49@app.route('/login', methods=["GET", "POST"])
50def login():
51    form = LoginForm()
52    if request.method == 'POST':
53        if form.validate_on_submit():
54            candidate_user = User.query.filter(User.email == form.email.data).first()
55
56            if candidate_user is None or not bcrypt.check_password_hash(candidate_user.password,
57                                                                        form.password.data):
58                form.password.errors.append("Invalid credentials.")
59                return view('login', form)
60
61            login_user(candidate_user, remember=True)
62            return redirect_to('home')
63    return view('login', form)
64
65
66@app.route('/logout', methods=["POST"])
67@login_required
68def logout():
69    logout_user()
70    return redirect_to('home')
71
72
73@app.route('/home', methods=["GET"])
74@login_required
75def home():
76    return view('home')
77
78
79@app.route('/properties', methods=["GET"])
80@login_required
81def properties():
82    vacation_properties = VacationProperty.query.all()
83    return view_with_params('properties', vacation_properties=vacation_properties)
84
85
86@app.route('/properties/new', methods=["GET", "POST"])
87@login_required
88def new_property():
89    form = VacationPropertyForm()
90    if request.method == 'POST':
91        if form.validate_on_submit():
92            host = User.query.get(current_user.get_id())
93
94            property = VacationProperty(form.description.data, form.image_url.data, host)
95            db.session.add(property)
96            db.session.commit()
97            return redirect_to('properties')
98
99    return view('property_new', form)
100
101
102@app.route('/reservations/', methods=["POST"], defaults={'property_id': None})
103@app.route('/reservations/<property_id>', methods=["GET", "POST"])
104@login_required
105def new_reservation(property_id):
106    vacation_property = None
107    form = ReservationForm()
108    form.property_id.data = property_id
109
110    if request.method == 'POST':
111        if form.validate_on_submit():
112            guest = User.query.get(current_user.get_id())
113
114            vacation_property = VacationProperty.query.get(form.property_id.data)
115            reservation = Reservation(form.message.data, vacation_property, guest)
116            db.session.add(reservation)
117            db.session.commit()
118
119            reservation.notify_host()
120
121            return redirect_to('properties')
122
123    if property_id is not None:
124        vacation_property = VacationProperty.query.get(property_id)
125
126    return view_with_params('reservation', vacation_property=vacation_property, form=form)
127
128
129@app.route('/reservations', methods=["GET"])
130@login_required
131def reservations():
132    user = User.query.get(current_user.get_id())
133
134    reservations_as_host = Reservation.query \
135        .filter(VacationProperty.host_id == current_user.get_id() and len(VacationProperty.reservations) > 0) \
136        .join(VacationProperty) \
137        .filter(Reservation.vacation_property_id == VacationProperty.id) \
138        .all()
139
140    reservations_as_guest = user.reservations
141
142    return view_with_params('reservations',
143                            reservations_as_guest=reservations_as_guest,
144                            reservations_as_host=reservations_as_host)
145
146
147@app.route('/reservations/confirm', methods=["POST"])
148def confirm_reservation():
149    form = ReservationConfirmationForm()
150    sms_response_text = "Sorry, it looks like you don't have any reservations to respond to."
151
152    user = User.query.filter(User.phone_number == form.From.data).first()
153    reservation = Reservation \
154        .query \
155        .filter(Reservation.status == 'pending'
156                and Reservation.vacation_property.host.id == user.id) \
157        .first()
158
159    if reservation is not None:
160
161        if 'yes' in form.Body.data or 'accept' in form.Body.data:
162            reservation.confirm()
163            reservation.buy_number(user.area_code)
164        else:
165            reservation.reject()
166
167        db.session.commit()
168
169        sms_response_text = "You have successfully {0} the reservation".format(reservation.status)
170        reservation.notify_guest()
171
172    return twiml(_respond_message(sms_response_text))
173
174
175@app.route('/exchange/sms', methods=["POST"])
176def exchange_sms():
177    form = ExchangeForm()
178
179    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
180
181    response = MessagingResponse()
182    response.message(form.Body.data, to=outgoing_number)
183    return twiml(response)
184
185
186@app.route('/exchange/voice', methods=["POST"])
187def exchange_voice():
188    form = ExchangeForm()
189    outgoing_number = _gather_outgoing_phone_number(form.From.data, form.To.data)
190
191    response = VoiceResponse()
192    response.play("http://howtodocs.s3.amazonaws.com/howdy-tng.mp3")
193    response.dial(outgoing_number)
194    return twiml(response)
195
196
197# controller utils
198@app.before_request
199def before_request():
200    g.user = current_user
201    uri_pattern = request.url_rule
202    if current_user.is_authenticated and (
203                        uri_pattern == '/' or uri_pattern == '/login' or uri_pattern == '/register'):
204        redirect_to('home')
205
206
207@login_manager.user_loader
208def load_user(id):
209    try:
210        return User.query.get(id)
211    except:
212        return None
213
214
215def _gather_outgoing_phone_number(incoming_phone_number, anonymous_phone_number):
216    reservation = Reservation.query \
217        .filter(Reservation.anonymous_phone_number == anonymous_phone_number) \
218        .first()
219
220    if reservation is None:
221        raise Exception('Reservation not found for {0}'.format(incoming_phone_number))
222
223    if reservation.guest.phone_number == incoming_phone_number:
224        return reservation.vacation_property.host.phone_number
225
226    return reservation.guest.phone_number
227
228
229def _respond_message(message):
230    response = MessagingResponse()
231    response.message(message)
232    return response

That's it! We've just implemented anonymous communications that allow your customers to connect while protecting their privacy.

Where to Next?

If you're a Python developer working with Twilio you might want to check out these other tutorials:

IVR: Phone Tree

Create a seamless customer service experience by building an IVR Phone Tree for your company.

Call Tracking

Measure the effectiveness of different marketing campaigns by assigning a unique phone number to different advertisements and track which ones have the best call rates while getting some data about the callers themselves.

Did this help?

Thanks for checking out this tutorial! If you have any feedback to share with us, we'd love to hear it. Tweet @twilio to let us know what you think.