django-stripe-billing 0.1.0

Reusable Django app for Stripe Checkout billing: webhook handling, checkout sessions, signals, and admin.

django-stripe-billing

A reusable Django app for Stripe Checkout billing. Handles webhook intake, idempotency, async Celery processing, checkout sessions, billing portal, and Django signals — so each of your SaaS projects gets billing in minutes, not days.

Features

• ✅ Stripe Checkout — create_checkout_session() helper
• ✅ Customer Portal — create_billing_portal_session() helper
• ✅ Subscription management — cancel, change plan helpers
• ✅ Webhook receiver — signature verification, livemode guard, idempotency
• ✅ Async processing — Celery task with exponential backoff on transient errors
• ✅ Django signals — connect custom logic per event type without touching the package
• ✅ Outgoing webhooks — Zapier / Make / n8n integration per event type
• ✅ Admin — StripeWebhookEvent with status badges and full-text search
• ✅ Python 3.10+, Django 4.2+

Quick Start

1. Install

pip install django-stripe-billing
# Optional: async webhook processing (recommended for production)
pip install django-stripe-billing[celery]
# or, during development:
pip install -e /path/to/django-stripe-billing

Without the [celery] extra, webhooks are processed synchronously in the request. With [celery], processing runs in a Celery task for a fast HTTP response and automatic retries.

2. Add to INSTALLED_APPS

INSTALLED_APPS = [
    ...
    'django_stripe_billing',
]

3. Configure

# settings.py
STRIPE_BILLING = {
    'STRIPE_SECRET_KEY': env('STRIPE_SECRET_KEY'),
    'STRIPE_WEBHOOK_SECRET': env('STRIPE_WEBHOOK_SECRET'),
    'STRIPE_MODE': 'live',           # 'live' or 'test'
    'ENVIRONMENT': env('ENVIRONMENT', default='production'),
    'APP_TITLE': 'My SaaS',
    'APP_DOMAIN': 'https://myapp.com',
    'SUPPORT_EMAIL': '[e-mail]',
    'EMAIL_SUBJECT_PREFIX': '[My SaaS]',
    # Optional: outgoing webhooks for Zapier / Make / n8n
    'OUTGOING_WEBHOOK_URLS': {
        'invoice.payment_succeeded': env('WEBHOOK_PAYMENT_SUCCEEDED', default=''),
        'invoice.payment_failed': env('WEBHOOK_PAYMENT_FAILED', default=''),
        'customer.subscription.deleted': env('WEBHOOK_SUBSCRIPTION_DELETED', default=''),
    },
}

Zero-config migration: If you already have STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET, etc. as top-level settings, the package reads them automatically — no changes required.

Required for production: STRIPE_SECRET_KEY and STRIPE_WEBHOOK_SECRET must be non-empty when using checkout/portal or the webhook endpoint; otherwise the app raises ImproperlyConfigured. See INTEGRATION.md for adding the package to existing projects (e.g. mobileapi_dev, signupcheck, tpscheck_uk).

4. Add URL

# urls.py
from django.urls import path, include

urlpatterns = [
    path('webhooks/', include('django_stripe_billing.urls')),
    # Exposes: POST /webhooks/stripe/
]

5. Run migrations

python manage.py migrate

---

Creating a Checkout Session

from django_stripe_billing.checkout import create_checkout_session

session = create_checkout_session(
    price_id='price_1Nxyz...',
    success_url=request.build_absolute_uri('/payment-success/?session_id={CHECKOUT_SESSION_ID}'),
    cancel_url=request.build_absolute_uri('/billing/'),
    user=request.user,
    metadata={'plan_id': 'pro_monthly'},
    subscription_metadata={'plan_id': 'pro_monthly', 'new_signup': 'true'},
)
return redirect(session.url, code=303)

Opening the Customer Portal

from django_stripe_billing.checkout import create_billing_portal_session

session = create_billing_portal_session(
    customer_id=request.user.userprofile.stripe_customer_id,
    return_url=request.build_absolute_uri('/billing/'),
)
return redirect(session.url, code=303)

---

Connecting Business Logic via Signals

Each Stripe event fires a Django signal. Connect your app-specific logic here:

# myapp/signals.py
from django.dispatch import receiver
from django_stripe_billing.signals import (
    payment_succeeded,
    payment_failed,
    subscription_deleted,
    trial_will_end,
)
from myapp.models import UserProfile


@receiver(payment_succeeded)
def on_payment_succeeded(sender, invoice, **kwargs):
    customer_id = invoice.get('customer')
    try:
        profile = UserProfile.objects.get(stripe_customer_id=customer_id)
    except UserProfile.DoesNotExist:
        return
    # Update plan, reset credits, etc.
    profile.plan = _resolve_plan(invoice)
    profile.save()


@receiver(payment_failed)
def on_payment_failed(sender, invoice, attempt_count, **kwargs):
    customer_id = invoice.get('customer')
    try:
        profile = UserProfile.objects.get(stripe_customer_id=customer_id)
    except UserProfile.DoesNotExist:
        return
    if attempt_count == 1:
        send_payment_failed_email_1(profile.user)
    elif attempt_count == 2:
        send_payment_failed_email_2(profile.user)


@receiver(subscription_deleted)
def on_subscription_deleted(sender, subscription, **kwargs):
    customer_id = subscription.get('customer')
    try:
        profile = UserProfile.objects.get(stripe_customer_id=customer_id)
    except UserProfile.DoesNotExist:
        return
    old_plan = profile.plan
    profile.plan = 'free'
    profile.save()
    send_subscription_cancelled_email(profile.user, old_plan)

Register your signal receivers in apps.py:

# myapp/apps.py
class MyAppConfig(AppConfig):
    name = 'myapp'

    def ready(self):
        import myapp.signals  # noqa: F401

---

Available Signals

Signal	kwargs
payment_succeeded	invoice, user, user_payment
payment_failed	invoice, user, attempt_count
checkout_completed	session, user_payment
subscription_updated	subscription, user
subscription_deleted	subscription, user, old_plan
charge_refunded	charge, user, amount_display
trial_will_end	subscription, user, trial_end_date
subscription_paused	subscription, user
payment_method_attached	payment_method, user

user and user_payment are None in the default handlers — they are provided by your signal receiver after looking up models from customer_id.

---

Custom Webhook Handlers

Override or add handlers to the registry:

from django_stripe_billing.webhooks import registry

@registry.handler('invoice.payment_succeeded')
def my_custom_handler(data_object):
    # This replaces the built-in handler for this event type
    ...

# Or register a handler for an event type not built-in:
@registry.handler('customer.created')
def handle_customer_created(data_object):
    ...

---

Subscription Helpers

from django_stripe_billing.checkout import cancel_subscription, change_subscription_price

# Cancel at end of current period (default)
cancel_subscription(customer_id='cus_...')

# Cancel immediately
cancel_subscription(customer_id='cus_...', at_period_end=False)

# Change plan
change_subscription_price(customer_id='cus_...', new_price_id='price_new...')

---

Architecture

django_stripe_billing/
├── conf.py          # Settings helper (STRIPE_BILLING dict + legacy fallback)
├── models.py        # StripeWebhookEvent (idempotency + audit trail)
├── signals.py       # Django signals, one per Stripe event type
├── webhooks.py      # HandlerRegistry + built-in handlers
├── checkout.py      # create_checkout_session(), create_billing_portal_session(), etc.
├── utils.py         # number_to_currency(), fire_outgoing_webhook()
├── tasks.py         # Celery task: async processing + exponential backoff
├── views.py         # HTTP webhook receiver (signature verify, livemode guard)
├── admin.py         # StripeWebhookEvent admin
└── urls.py          # path('stripe/', stripe_webhook)

How a webhook flows through the package:

Stripe → POST /webhooks/stripe/
  ↓ views.py — verify signature, guard livemode, persist StripeWebhookEvent
  ↓ tasks.py — Celery task picks up event, calls registry.dispatch()
  ↓ webhooks.py — built-in handler fires Django signal + outgoing webhook
  ↓ your app — signal receiver implements business logic

---

Integration into existing projects

If your project already uses Stripe with top-level settings (STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET, STRIPE_MODE, etc.), see INTEGRATION.md for step-by-step integration with minimal change, including projects that already have a custom webhook handler or Celery.

Stripe best practices (built in)

• Webhook signature verification — All requests are verified with STRIPE_WEBHOOK_SECRET; invalid payloads return 400.
• Livemode guard — Test events are ignored in production and live events in non-production, so keys and environment stay consistent.
• Idempotency — Events are stored by stripe_event_id; duplicates return 200 without reprocessing.
• Never rely only on client-side success — Use the webhook and signals to update plans and fulfil access; see Stripe docs.

Development

git clone https://github.com/visian-systems/django-stripe-billing
cd django-stripe-billing
pip install -e ".[dev]"
# With Celery for local webhook testing:
pip install -e ".[dev,celery]"
pytest

Running tests

From the project root:

pytest

For verbose output and short tracebacks:

pytest -v --tb=short

Tests use an in-memory SQLite database and mock Stripe/HTTP; no real API keys are required. See TESTING.md for layout, options, and TDD notes.

License

MIT