Django Stripe Integration

This tutorial will teach you about how to integrate your django application with stripe.

1. Base Project

• Show a demo of the base project

2. Install & Configure Stripe

• Install stripe:

  pip install stripe

• Head to your stripe dashboard to get api key and publishable key: https://dashboard.stripe.com/test/developers

• Add stripe api key, publishable key to settings.py file:

  STRIPE_SECRET_KEY = config('STRIPE_SECRET_KEY')
  STRIPE_PUBLISHABLE_KEY = config('STRIPE_PUBLISHABLE_KEY')

  • Note: The above code makes use of the decouple library to get environment variables from the .env file. In order to use this library, you have to first install it:

  pip install python-decouple

  And then import it at the top of your settings.py file:

  from decouple import config

3. Stripe Checkout Endpoint

• Next, we need to setup the stripe checkout endpoint

• Import and initialize stripe in payment app views.py file:

  from django.shortcuts import redirect
  from django.conf import settings
  from django.contrib.auth.decorators import login_required
  import stripe
  
  stripe.api_key = settings.STRIPE_SECRET_KEY

• In payment app views.py, create a new view to handle checkout:

  @login_required
  def CreateCheckoutSessionView(request, product_id):
      ...

• In the view, we need to first get the producy using the product_id url parameter:

  @login_required
  def CreateCheckoutSessionView(request, product_id):
      product = Product.objects.get(id=product_id)

• Next, create a stripe checkout session:

  • More documentation for this is here: https://docs.stripe.com/checkout/quickstart?client=html

  @login_required
  def CreateCheckoutSessionView(request, product_id):
      product = Product.objects.get(id=product_id)
  
      YOUR_DOMAIN = f"{request.scheme}://{request.get_host()}"
      
      checkout_session = stripe.checkout.Session.create(
          payment_method_types=['card'],
          line_items=[
              {
                  'price_data': {
                      'currency': 'usd',
                      'unit_amount': product.price * 100,
                      'product_data': {
                          'name': product.name,
                          'images': [f'{product.image}']
                      },
                  },
                  'quantity': 1,
              },
          ],
          metadata = {
              'product_id': product_id,
              'user_email': request.user.email
          },
          
          mode='payment',
  
          success_url=YOUR_DOMAIN + f'/payment-success/{product_id}',
          cancel_url=YOUR_DOMAIN + f'/pricing/{product_id}',
      )
  
      return redirect(checkout_session.url)

• Create a url for checkout endpoint:

  path('checkout/<int:product_id>/', views.CreateCheckoutSessionView, name='checkout'),

• Next, update the pricing.html file to properly redirect to the stripe check out page when the purchase button is clicked:

  <!-- wrap button in anchor tag  -->
  <a href="{% url 'checkout' product.id %}"><button>Purchase</button></a>

• Test the integration with test card:

  4242424242424242

4. Get Stripe Webhook Secret

• What is a webhook?

  • 

• Get webhook secret from stripe dashboard:

  https://dashboard.stripe.com/test/webhooks

• What is ngrok?

• Install ngrok:

  https://download.ngrok.com/

• Create a new ngrok url to expose local development server to public internet access:

  • Make sure your django development server is running and the run the following command:

    ngrok http 8000

• Copy the generated ngrok url and paste into the Endpoint URL field in stripe dashboard

• Optionally add a description about what this endpoint is for

• Slect the following events to listen to:

  checkout.session.completed
  checkout.session.async_payment_failed

• Go back to your views.py file and create a view to handle this webhook and map view to url:

  from django.views.decorators.csrf import csrf_exempt
  
  def stripe_webhook(request):
      ...

  In your urls.py file:

  path('stripe/webhook/', views.stripe_webhook, name='stripe-webhook'),

• Next, head back to your browser and copy the code provided by stripe towards the right-hand side of the page:

  from django.views.decorators.csrf import csrf_exempt
  
  @csrf_exempt
  def stripe_webhook(request):
     event = None
     payload = request.data
     sig_header = request.headers['STRIPE_SIGNATURE']
  
     try:
         event = stripe.Webhook.construct_event(
             payload, sig_header, endpoint_secret
         )
     except ValueError as e:
         # Invalid payload
         raise e
     except stripe.error.SignatureVerificationError as e:
         # Invalid signature
         raise e
  
     # Handle the event
     if event['type'] == 'checkout.session.completed':
         session = event['data']['object']
     elif event['type'] == 'checkout.session.async_payment_failed':
         session = event['data']['object']
  
     else:
         print('Unhandled event type {}'.format(event['type']))
  
     return jsonify(success=True)

• Now we will make changes to this code because it is written for flask:

  • First is to change the payload and sig_header to this:

    payload = request.body # replaced payload = request.data
    sig_header = request.META['HTTP_STRIPE_SIGNATURE'] # replaced request.headers['STRIPE_SIGNATURE']

  • Correctly pass in the endpoint_secret:

    settings.STRIPE_WEBHOOK_SECRET # replaced endpoint_secret

  • Next, inside each exception, instead of raising an exception, we will return a HTTP response back to stripe:

    return HttpResponse(status=400) # replaced raise e

  • Replace the final response with this:

    return HttpResponse(status=200) # replaced return jsonify(success=True)

• Go back to browser and click Add events and the click Add endpoint

• Copy and Save webhook secret in settings.py file:

  STRIPE_WEBHOOK_SECRET = config('STRIPE_WEBHOOK_SECRET')

5. Handle Successful and Failed Events

• For successful events, we can proceed to create a new purchase PurchaseHistory for this product and optionally email the user.

  • We can get the product id and user email below:

    if event['type'] == 'checkout.session.completed':
        session = event['data']['object']
    
        product_id = session['metadata']['product_id']
        user_email = session['metadata']['user_email']

  • Next, we can create a new PurchaseHistory:

    if event['type'] == 'checkout.session.completed':
       session = event['data']['object']
    
       product_id = session['metadata']['product_id']
       user_email = session['metadata']['user_email']
    
       get_product = Product.objects.get(id=product_id)
    
       PurchaseHistory.objects.create(product=get_product, purchase_success=True)
    
       # send success email to user to let them know purchase is complete
       ...

  • Finally, we can handle a failed purchase here:

    elif event['type'] == 'checkout.session.async_payment_failed':
        session = event['data']['object']
    
        product_id = session['metadata']['product_id']
        user_email = session['metadata']['user_email']
    
        get_product = Product.objects.get(id=product_id)
    
        PurchaseHistory.objects.create(product=get_product)
    
        # send failed email to user to let them know purchase is complete

6. Test the code

• Generate a new ngrok url for local development server and replace old url in webhook setting in stripe dashboard:

  ngrok http 8000