Receive and Download Images on Incoming Media Messages with Python and Django

You know how to receive and reply to incoming SMS messages. What if you receive an MMS message containing an image you'd like to download? Let's learn how we can grab that image and any other incoming MMS media using Django.

Create MMS processing project

Create a Django application

When Twilio receives a message for your phone number, it can make an HTTP call to a webhook that you create.

Twilio expects, at the very least, for your webhook to return a 200 OK response if everything is peachy. Often, however, you will return some TwiML in your response as well. TwiML is just a set of XML commands telling Twilio how you'd like it to respond to your message. Rather than manually generating the XML, we'll use the twilio.twiml.messaging_response module in the helper library to facilitate generating TwiML and the rest of the webhook plumbing.

To install the library, run:

pip install twilio

Create Router

Add a new route in your urls.py file that handles incoming SMS requests.

Handle Incoming SMS Routes - Django

1from django.conf import settings
2from django.conf.urls import url
3from django.conf.urls.static import static
4
5from . import views
6
7urlpatterns = [
8    url(r'^$', views.index, name='index'),
9    url(r'^config/$', views.config, name='config'),
10    url(r'^images/$', views.get_all_media, name='images'),
11    url(r'^images/(?P<filename>[0-9A-Za-z\.]{0,50})$', views.handle_delete_media_file, name='delete_image'),
12    url(r'^incoming/$', views.handle_incoming_message, name='incoming'),
13]
14
15if settings.DEBUG:
16    urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)

Receive MMS message and images

Get Incoming Message Details

When Twilio calls your webhook, it sends a number of parameters about the message you just received. Most of these, such as the To phone number, the From phone number, and the Body of the message are available as properties of the request body.

Get URLs to the Media

Since an MMS message can have multiple attachments, Twilio will send us form variables named MediaUrlX, where X is a zero-based index. So, for example, the URL for the first media attachment will be in the MediaUrl0 parameter, the second in MediaUrl1, and so on.

In order to handle a dynamic number of attachments, we pull the URLs out of the request body like this:

Handle Incoming SMS Views - Django

1import os
2import sys
3import logging
4import mimetypes
5import requests
6
7from django.core import serializers
8from django.http import HttpResponse, JsonResponse
9from django.shortcuts import render
10from django.views.decorators.csrf import csrf_exempt
11from core.receive_mms import *
12
13
14logger = logging.getLogger(__name__)
15
16
17def index(request):
18    return render(request, 'receive_mms/index.html')
19
20
21def config(_):
22    return JsonResponse({'twilioPhoneNumber': os.getenv('TWILIO_NUMBER', '')})
23
24
25# /images/
26def get_all_media(_):
27    return JsonResponse({'data': fetch_all_media()})
28
29
30# /images/:filename
31@csrf_exempt
32def handle_delete_media_file(_, filename=None):
33    try:
34        media_content, mime_type = delete_media_file(filename)
35        return HttpResponse(media_content, content_type=mime_type)
36    except MMSMedia.DoesNotExist as err:
37        logger.error(err)
38        return JsonResponse({
39            'status': False,
40            'message': 'Could not find any media file with name: {}'.format(filename)
41          }, status=404)
42
43
44# /incoming/
45@csrf_exempt
46def handle_incoming_message(request):
47    message_sid = request.POST.get('MessageSid', '')
48    from_number = request.POST.get('From', '')
49    num_media = int(request.POST.get('NumMedia', 0))
50
51    media_files = [(request.POST.get("MediaUrl{}".format(i), ''),
52                    request.POST.get("MediaContentType{}".format(i), ''))
53                   for i in range(0, num_media)]
54
55    response = reply_with_twiml_message(message_sid, from_number, num_media, media_files)
56    return HttpResponse(response, content_type='application/xml')

Determine content type of media

Attachments to MMS messages can be of many different file types. JPG and GIF images as well as MP4 and 3GP files are all common. Twilio handles the determination of the file type for you and you can get the standard mime type from the MediaContentTypeX parameter. If you are expecting photos, then you will likely see a lot of attachments with the mime type image/jpeg.

Map MIME Type To File Extension

1import os
2import mimetypes
3import requests
4
5from twilio.rest import Client
6from twilio.twiml.messaging_response import MessagingResponse
7from core.models import MMSMedia
8
9# Python 2 and 3: alternative 4
10try:
11    from urllib.parse import urlparse
12except ImportError:
13    from urlparse import urlparse
14
15
16def reply_with_twiml_message(message_sid, from_number, num_media, media_files):
17    if not from_number or not message_sid:
18        raise Exception('Please provide a From Number and a Message Sid')
19
20    for (media_url, mime_type) in media_files:
21        file_extension = mimetypes.guess_extension(mime_type)
22        media_sid = os.path.basename(urlparse(media_url).path)
23        content = requests.get(media_url).text
24        filename = '{sid}{ext}'.format(sid=media_sid, ext=file_extension)
25
26        mms_media = MMSMedia(
27            filename=filename,
28            mime_type=mime_type,
29            media_sid=media_sid,
30            message_sid=message_sid,
31            media_url=media_url,
32            content=content)
33        mms_media.save()
34
35    response = MessagingResponse()
36    message = 'Send us an image!' if not num_media else 'Thanks for the {} images.'.format(num_media)
37    response.message(body=message, to=from_number, from_=os.getenv('TWILIO_NUMBER'))
38    return response
39
40
41def delete_media_file(filename=None):
42    m = MMSMedia.objects.get(filename=filename)
43    _twilio_client().api.messages(m.message_sid) \
44        .media(m.media_sid) \
45        .delete()
46    m.delete()
47
48    return m.content, m.mime_type
49
50
51def fetch_all_media():
52    return map(lambda mms: mms.filename, MMSMedia.objects.all())
53
54
55def _twilio_client():
56    account_sid = os.getenv('TWILIO_ACCOUNT_SID')
57    auth_token = os.getenv('TWILIO_AUTH_TOKEN')
58
59    return Client(account_sid, auth_token)

Process MMS images

Save the media URLs

Depending on your use case, storing the URLs of the images (or videos or whatever) may be all you need. There are two key features to these URLs that make them very pliable for your use in your apps:

They are publicly accessible without any need for authentication to facilitate sharing.
They are permanent (unless you explicitly delete the media).

For example, if you are building a browser-based app that needs to display the images, all you need to do is drop an <img src="twilio url to your image"> tag into the page. If this works for you, then perhaps all you need is to store the URL in a database character field.

Save media to local file system

If you want to save the media attachments to a file, then you will need to make an HTTP request to the media URL and write the response stream to a file. If you need a unique filename, you can use the last part of the media URL. For example, suppose your media URL is the following:

https://api.twilio.com/2010-04-01/Accounts/ACxxxx/Messages/MMxxxx/Media/ME27be8a708784242c0daee207ff73db67

You can use that last part of the URL as a unique filename and look up the corresponding file extension for the mime type.

Handle Incoming SMS Endpoints - Django

1import os
2import mimetypes
3import requests
4
5from twilio.rest import Client
6from twilio.twiml.messaging_response import MessagingResponse
7from core.models import MMSMedia
8
9# Python 2 and 3: alternative 4
10try:
11    from urllib.parse import urlparse
12except ImportError:
13    from urlparse import urlparse
14
15
16def reply_with_twiml_message(message_sid, from_number, num_media, media_files):
17    if not from_number or not message_sid:
18        raise Exception('Please provide a From Number and a Message Sid')
19
20    for (media_url, mime_type) in media_files:
21        file_extension = mimetypes.guess_extension(mime_type)
22        media_sid = os.path.basename(urlparse(media_url).path)
23        content = requests.get(media_url).text
24        filename = '{sid}{ext}'.format(sid=media_sid, ext=file_extension)
25
26        mms_media = MMSMedia(
27            filename=filename,
28            mime_type=mime_type,
29            media_sid=media_sid,
30            message_sid=message_sid,
31            media_url=media_url,
32            content=content)
33        mms_media.save()
34
35    response = MessagingResponse()
36    message = 'Send us an image!' if not num_media else 'Thanks for the {} images.'.format(num_media)
37    response.message(body=message, to=from_number, from_=os.getenv('TWILIO_NUMBER'))
38    return response
39
40
41def delete_media_file(filename=None):
42    m = MMSMedia.objects.get(filename=filename)
43    _twilio_client().api.messages(m.message_sid) \
44        .media(m.media_sid) \
45        .delete()
46    m.delete()
47
48    return m.content, m.mime_type
49
50
51def fetch_all_media():
52    return map(lambda mms: mms.filename, MMSMedia.objects.all())
53
54
55def _twilio_client():
56    account_sid = os.getenv('TWILIO_ACCOUNT_SID')
57    auth_token = os.getenv('TWILIO_AUTH_TOKEN')
58
59    return Client(account_sid, auth_token)

Another idea for these image files could be uploading them to a cloud storage service like Azure Blob Storage or Amazon S3. You could also save them to a database, if necessary. They're just regular files at this point - let your DevOps creativity run free! In this case, we are saving them to the public directory in order to serve them later.

Delete media from Twilio

If you are downloading the attachments and no longer need them to be stored by Twilio, you can delete them by sending an HTTP DELETE request to the media URL. You will need to be authenticated to do this. The code below demonstrates how to make this request.

Delete Media From Twilio Servers

1import os
2import mimetypes
3import requests
4
5from twilio.rest import Client
6from twilio.twiml.messaging_response import MessagingResponse
7from core.models import MMSMedia
8
9# Python 2 and 3: alternative 4
10try:
11    from urllib.parse import urlparse
12except ImportError:
13    from urlparse import urlparse
14
15
16def reply_with_twiml_message(message_sid, from_number, num_media, media_files):
17    if not from_number or not message_sid:
18        raise Exception('Please provide a From Number and a Message Sid')
19
20    for (media_url, mime_type) in media_files:
21        file_extension = mimetypes.guess_extension(mime_type)
22        media_sid = os.path.basename(urlparse(media_url).path)
23        content = requests.get(media_url).text
24        filename = '{sid}{ext}'.format(sid=media_sid, ext=file_extension)
25
26        mms_media = MMSMedia(
27            filename=filename,
28            mime_type=mime_type,
29            media_sid=media_sid,
30            message_sid=message_sid,
31            media_url=media_url,
32            content=content)
33        mms_media.save()
34
35    response = MessagingResponse()
36    message = 'Send us an image!' if not num_media else 'Thanks for the {} images.'.format(num_media)
37    response.message(body=message, to=from_number, from_=os.getenv('TWILIO_NUMBER'))
38    return response
39
40
41def delete_media_file(filename=None):
42    m = MMSMedia.objects.get(filename=filename)
43    _twilio_client().api.messages(m.message_sid) \
44        .media(m.media_sid) \
45        .delete()
46    m.delete()
47
48    return m.content, m.mime_type
49
50
51def fetch_all_media():
52    return map(lambda mms: mms.filename, MMSMedia.objects.all())
53
54
55def _twilio_client():
56    account_sid = os.getenv('TWILIO_ACCOUNT_SID')
57    auth_token = os.getenv('TWILIO_AUTH_TOKEN')
58
59    return Client(account_sid, auth_token)

(warning)

Protect your webhooks

Twilio supports HTTP Basic and Digest Authentication. Authentication allows you to password protect your TwiML URLs on your web server so that only you and Twilio can access them. Learn more about HTTP authentication and validating incoming requests here.

What's Next?

All the code, in a complete working project, is available on GitHub. If you need to dig a bit deeper, you can head over to our API Reference and learn more about the Twilio webhook request and the REST API Media resource. Also, you will want to be aware of the pricing for storage of all the media files that you keep on Twilio's servers.

We'd love to hear what you build with this.