Function create_checkout_session

api/payments.py:306–373

Creates a Stripe Checkout session for the currently authenticated user to purchase the Pro plan. The user's Auth0 ID is passed to Stripe for identification in webhooks.

(current_user: AuthUser, body: CheckoutRequest = None)

    summary="Create Stripe Checkout Session for New Subscription"
)
async def create_checkout_session(current_user: AuthUser, body: CheckoutRequest = None):
    """
    Creates a Stripe Checkout session for the currently authenticated user to
    purchase the Pro plan. The user's Auth0 ID is passed to Stripe for
    identification in webhooks.
    """
    base_url = get_base_url(body.return_base_url if body else None)

    has_sub, existing_id, provider, active_customer_id = _get_subscription_from_metadata(current_user)
    if has_sub:
        if provider == "apple":
            raise HTTPException(
                status_code=400,
                detail="You have an active Apple subscription. Please cancel it in iOS Settings before purchasing via Stripe."
            )
        elif provider == "stripe" and active_customer_id:
            portal = stripe.billing_portal.Session.create(
                customer=active_customer_id,
                return_url=f"{base_url}/refresh",
            )
            return {"url": portal.url, "redirect": "portal"}

    try:
        # Get or create Stripe customer with Auth0 email to prevent Link email mismatch
        customer_id = get_or_create_stripe_customer(current_user)

        # Check if user has already used a free trial
        had_trial = False
        if customer_id:
            try:
                past_subs = stripe.Subscription.list(customer=customer_id, status='all', limit=100)
                had_trial = any(sub.trial_end is not None for sub in past_subs.data)
            except Exception as e:
                logger.warning(f"Failed to check trial history for {current_user.id}: {e}")

        # Check ghost customers — accounts that were deleted and re-registered with the same email
        if not had_trial and hasattr(current_user, 'email') and current_user.email:
            try:
                email_hash = hashlib.sha256(current_user.email.lower().encode()).hexdigest()
                ghost_customers = stripe.Customer.list(email=f"{email_hash}@deleted.invalid", limit=100)
                for ghost in ghost_customers.data:
                    past_subs = stripe.Subscription.list(customer=ghost.id, status='all', limit=100)
                    if any(sub.trial_end is not None for sub in past_subs.data):
                        had_trial = True
                        break
            except Exception as e:
                logger.warning(f"Failed to check ghost trial history for {current_user.id}: {e}")

        checkout_params = {
            "line_items": [{"price": PRO_PRICE_ID, "quantity": 1}],
            "mode": "subscription",
            "client_reference_id": current_user.id,
            "success_url": f"{base_url}/upgrade-success",
            "cancel_url": base_url,
            "allow_promotion_codes": True,
        }

        if not had_trial: