> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dodopayments.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Upsells & Downsells

> Increase revenue with one-click purchases using saved payment methods for post-purchase offers, subscription upgrades, and cross-sells.

<Info>
  تُتيح عمليات الترقيات والتخفيضات عرض منتجات إضافية أو تغييرات في الخطط للعملاء باستخدام طرق الدفع المحفوظة لديهم. هذا يمكِّن من عمليات شراء بنقرة واحدة تتخطى جمع بيانات الدفع، مما يحسّن معدلات التحويل بشكل كبير.
</Info>

<CardGroup cols={3}>
  <Card title="Post-Purchase Upsells" icon="cart-plus">
    عرض منتجات تكميلية فور الانتهاء من الدفع مع إمكانية شراء بنقرة واحدة.
  </Card>

  <Card title="Subscription Upgrades" icon="arrow-up">
    نقل العملاء إلى مستويات أعلى مع التوزيع التلقائي للرسوم والفوترة الفورية.
  </Card>

  <Card title="Cross-Sells" icon="grid-2-plus">
    إضافة منتجات ذات صلة للعملاء الحاليين دون الحاجة إلى إعادة إدخال بيانات الدفع.
  </Card>
</CardGroup>

## Overview

الترقيات والتخفيضات تعتبر استراتيجيات قوية لتحسين الإيرادات:

* **Upsells**: عرض منتج أعلى قيمة أو ترقية (مثل خطة Pro بدلًا من Basic)
* **Downsells**: عرض خيار بسعر أقل عندما يرفض العميل أو يطلب تخفيضًا
* **Cross-sells**: اقتراح منتجات تكميلية (مثل الإضافات أو العناصر ذات الصلة)

تمكِّن Dodo Payments هذه التدفقات عبر المعامل `payment_method_id`، الذي يتيح لك تحصيل مقابل طريقة الدفع المحفوظة للعميل دون الحاجة لإعادة إدخال تفاصيل البطاقة.

### Key Benefits

| Benefit                 | Impact                                           |
| ----------------------- | ------------------------------------------------ |
| **One-click purchases** | تخطي نموذج الدفع تمامًا للعملاء العائدين         |
| **Higher conversion**   | تقليل الاحتكاك في لحظة اتخاذ القرار              |
| **Instant processing**  | يتم معالجة الرسوم فورًا باستخدام `confirm: true` |
| **Seamless UX**         | يبقى العملاء داخل تطبيقك طوال التدفق             |

## How It Works

```mermaid theme={null}
sequenceDiagram
    participant C as Customer
    participant A as Your App
    participant D as Dodo API
    
    C->>A: Completes purchase
    A->>D: Get payment methods
    D-->>A: payment_method_id
    A->>C: Show upsell offer
    C->>A: Accept (one click)
    A->>D: Charge with payment_method_id
    D-->>A: Payment success
    D->>A: Webhook: payment.succeeded
```

## Prerequisites

قبل تنفيذ الترقيات والتخفيضات، تأكد من توفر ما يلي:

<Steps>
  <Step title="Customer with Saved Payment Method">
    يجب أن يكون العملاء قد أتمّوا عملية شراء واحدة على الأقل. يتم حفظ طرق الدفع تلقائيًا عند إكمال العملاء لعملية الدفع.
  </Step>

  <Step title="Products Configured">
    أنشئ منتجات الترقيات داخل لوحة Dodo Payments. يمكن أن تكون هذه مدفوعات لمرة واحدة أو اشتراكات أو إضافات.
  </Step>

  <Step title="Webhook Endpoint">
    أعدد Webhooks للتعامل مع أحداث `payment.succeeded`، `payment.failed`، و`subscription.plan_changed`.
  </Step>
</Steps>

## Getting Customer Payment Methods

قبل عرض ترقية، استرجع طرق الدفع المحفوظة للعميل:

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    import DodoPayments from 'dodopayments';

    const client = new DodoPayments({
      bearerToken: process.env.DODO_PAYMENTS_API_KEY,
      environment: 'live_mode',
    });

    async function getPaymentMethods(customerId: string) {
      const paymentMethods = await client.customers.retrievePaymentMethods(customerId);
      
      // Returns array of saved payment methods
      // Each has: payment_method_id, type, card (last4, brand, exp_month, exp_year)
      return paymentMethods;
    }

    // Example usage
    const methods = await getPaymentMethods('cus_123');
    console.log('Available payment methods:', methods);

    // Use the first available method for upsell
    const primaryMethod = methods[0]?.payment_method_id;
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    import os
    from dodopayments import DodoPayments

    client = DodoPayments(
        bearer_token=os.environ.get("DODO_PAYMENTS_API_KEY"),
        environment="live_mode",
    )

    def get_payment_methods(customer_id: str):
        payment_methods = client.customers.retrieve_payment_methods(customer_id)
        
        # Returns list of saved payment methods
        # Each has: payment_method_id, type, card (last4, brand, exp_month, exp_year)
        return payment_methods

    # Example usage
    methods = get_payment_methods("cus_123")
    print("Available payment methods:", methods)

    # Use the first available method for upsell
    primary_method = methods[0].payment_method_id if methods else None
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    package main

    import (
        "context"
        "fmt"
        "github.com/dodopayments/dodopayments-go"
        "github.com/dodopayments/dodopayments-go/option"
    )

    func getPaymentMethods(customerID string) ([]dodopayments.CustomerGetPaymentMethodsResponseItem, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        resp, err := client.Customers.GetPaymentMethods(
            context.TODO(),
            customerID,
        )
        if err != nil {
            return nil, err
        }
        
        return resp.Items, nil
    }

    func main() {
        methods, err := getPaymentMethods("cus_123")
        if err != nil {
            panic(err)
        }
        
        fmt.Println("Available payment methods:", methods)
        
        // Use the first available method for upsell
        if len(methods) > 0 {
            primaryMethod := methods[0].PaymentMethodID
            fmt.Println("Primary method:", primaryMethod)
        }
    }
    ```
  </Tab>
</Tabs>

<Info>
  يتم حفظ طرق الدفع تلقائيًا عند إكمال العملاء لعملية الدفع. لا تحتاج إلى حفظها يدويًا.
</Info>

## Post-Purchase One-Click Upsells

قدِّم منتجات إضافية فور إتمام عملية شراء ناجحة. يمكن للعميل القبول بنقرة واحدة لأن طريقة الدفع محفوظة بالفعل.

```mermaid theme={null}
flowchart LR
    A[Purchase] --> B{Upsell?}
    B -->|Yes| C[Show Offer]
    B -->|No| F[Done]
    C --> D{Accept?}
    D -->|Yes| E[One-Click Charge] --> F
    D -->|No| F
```

### Implementation

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    import DodoPayments from 'dodopayments';

    const client = new DodoPayments({
      bearerToken: process.env.DODO_PAYMENTS_API_KEY,
      environment: 'live_mode',
    });

    async function createOneClickUpsell(
      customerId: string,
      paymentMethodId: string,
      upsellProductId: string
    ) {
      // Create checkout session with saved payment method
      // confirm: true processes the payment immediately
      const session = await client.checkoutSessions.create({
        product_cart: [
          {
            product_id: upsellProductId,
            quantity: 1
          }
        ],
        customer: {
          customer_id: customerId
        },
        payment_method_id: paymentMethodId,
        confirm: true,  // Required when using payment_method_id
        return_url: 'https://yourapp.com/upsell-success',
        feature_flags: {
          redirect_immediately: true  // Skip success page
        },
        metadata: {
          upsell_source: 'post_purchase',
          original_order_id: 'order_123'
        }
      });

      return session;
    }

    // Example: Offer premium add-on after initial purchase
    async function handlePostPurchaseUpsell(customerId: string) {
      // Get customer's payment methods
      const methods = await client.customers.retrievePaymentMethods(customerId);
      
      if (methods.length === 0) {
        console.log('No saved payment methods available');
        return null;
      }

      // Create the upsell with one-click checkout
      const upsell = await createOneClickUpsell(
        customerId,
        methods[0].payment_method_id,
        'prod_premium_addon'
      );

      console.log('Upsell processed:', upsell.session_id);
      return upsell;
    }
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    import os
    from dodopayments import DodoPayments

    client = DodoPayments(
        bearer_token=os.environ.get("DODO_PAYMENTS_API_KEY"),
        environment="live_mode",
    )

    def create_one_click_upsell(
        customer_id: str,
        payment_method_id: str,
        upsell_product_id: str
    ):
        """Create a one-click upsell using saved payment method."""
        
        # Create checkout session with saved payment method
        # confirm=True processes the payment immediately
        session = client.checkout_sessions.create(
            product_cart=[
                {
                    "product_id": upsell_product_id,
                    "quantity": 1
                }
            ],
            customer={
                "customer_id": customer_id
            },
            payment_method_id=payment_method_id,
            confirm=True,  # Required when using payment_method_id
            return_url="https://yourapp.com/upsell-success",
            feature_flags={
                "redirect_immediately": True  # Skip success page
            },
            metadata={
                "upsell_source": "post_purchase",
                "original_order_id": "order_123"
            }
        )
        
        return session

    def handle_post_purchase_upsell(customer_id: str):
        """Offer premium add-on after initial purchase."""
        
        # Get customer's payment methods
        methods = client.customers.retrieve_payment_methods(customer_id)
        
        if not methods:
            print("No saved payment methods available")
            return None
        
        # Create the upsell with one-click checkout
        upsell = create_one_click_upsell(
            customer_id=customer_id,
            payment_method_id=methods[0].payment_method_id,
            upsell_product_id="prod_premium_addon"
        )
        
        print(f"Upsell processed: {upsell.session_id}")
        return upsell
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    package main

    import (
        "context"
        "fmt"
        "os"
        
        "github.com/dodopayments/dodopayments-go"
        "github.com/dodopayments/dodopayments-go/option"
    )

    func createOneClickUpsell(
        customerID string,
        paymentMethodID string,
        upsellProductID string,
    ) (*dodopayments.CheckoutSessionResponse, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        // Create checkout session with saved payment method
        // Confirm: true processes the payment immediately
        session, err := client.CheckoutSessions.New(context.TODO(), dodopayments.CheckoutSessionNewParams{
            CheckoutSessionRequest: dodopayments.CheckoutSessionRequestParam{
                ProductCart: dodopayments.F([]dodopayments.ProductItemReqParam{
                    {
                        ProductID: dodopayments.F(upsellProductID),
                        Quantity:  dodopayments.F(int64(1)),
                    },
                }),
                Customer: dodopayments.F[dodopayments.CustomerRequestUnionParam](
                    dodopayments.AttachExistingCustomerParam{
                        CustomerID: dodopayments.F(customerID),
                    },
                ),
                PaymentMethodID: dodopayments.F(paymentMethodID),
                Confirm:         dodopayments.F(true), // Required when using payment_method_id
                ReturnURL:       dodopayments.F("https://yourapp.com/upsell-success"),
                FeatureFlags: dodopayments.F(dodopayments.CheckoutSessionFlagsParam{
                    RedirectImmediately: dodopayments.F(true), // Skip success page
                }),
                Metadata: dodopayments.F(map[string]string{
                    "upsell_source":     "post_purchase",
                    "original_order_id": "order_123",
                }),
            },
        })
        
        return session, err
    }

    func handlePostPurchaseUpsell(customerID string) (*dodopayments.CheckoutSessionResponse, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        // Get customer's payment methods
        resp, err := client.Customers.GetPaymentMethods(context.TODO(), customerID)
        if err != nil {
            return nil, err
        }
        
        if len(resp.Items) == 0 {
            fmt.Println("No saved payment methods available")
            return nil, nil
        }
        
        // Create the upsell with one-click checkout
        upsell, err := createOneClickUpsell(
            customerID,
            resp.Items[0].PaymentMethodID,
            "prod_premium_addon",
        )
        if err != nil {
            return nil, err
        }
        
        fmt.Printf("Upsell processed: %s\n", upsell.SessionID)
        return upsell, nil
    }
    ```
  </Tab>
</Tabs>

<Warning>
  عند استخدام `payment_method_id`، يجب تعيين `confirm: true` وتوفير `customer_id` موجود مسبقًا. يجب أن تنتمي طريقة الدفع إلى ذلك العميل.
</Warning>

## Subscription Upgrades

نقل العملاء إلى خطط اشتراك أعلى مع التعامل التلقائي مع التوزيع النسبى للرسوم.

```mermaid theme={null}
sequenceDiagram
    participant C as Customer
    participant A as Your App
    participant D as Dodo API
    
    C->>A: Request upgrade
    A->>D: Preview change plan
    D-->>A: Charge amount
    A->>C: Confirm $50 charge?
    C->>A: Confirm
    A->>D: Change plan
    D->>A: Webhook: plan_changed
```

### Preview Before Committing

دائمًا اعرض معاينة لتغييرات الخطة لإظهار ما سيتم تحصيله بالضبط من العميل:

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    async function previewUpgrade(
      subscriptionId: string,
      newProductId: string
    ) {
      const preview = await client.subscriptions.previewChangePlan(subscriptionId, {
        product_id: newProductId,
        quantity: 1,
        proration_billing_mode: 'difference_immediately'
      });

      return {
        immediateCharge: preview.immediate_charge?.summary,
        newPlan: preview.new_plan,
        effectiveDate: preview.effective_date
      };
    }

    // Show customer the charge before confirming
    const preview = await previewUpgrade('sub_123', 'prod_pro_plan');
    console.log(`Upgrade will charge: ${preview.immediateCharge}`);
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    def preview_upgrade(subscription_id: str, new_product_id: str):
        preview = client.subscriptions.preview_change_plan(
            subscription_id=subscription_id,
            product_id=new_product_id,
            quantity=1,
            proration_billing_mode="difference_immediately"
        )
        
        return {
            "immediate_charge": preview.immediate_charge.summary if preview.immediate_charge else None,
            "new_plan": preview.new_plan,
            "effective_date": preview.effective_date
        }

    # Show customer the charge before confirming
    preview = preview_upgrade("sub_123", "prod_pro_plan")
    print(f"Upgrade will charge: {preview['immediate_charge']}")
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    func previewUpgrade(subscriptionID string, newProductID string) (map[string]interface{}, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        preview, err := client.Subscriptions.PreviewChangePlan(
            context.TODO(),
            subscriptionID,
            dodopayments.SubscriptionPreviewChangePlanParams{
                UpdateSubscriptionPlanReq: dodopayments.UpdateSubscriptionPlanReqParam{
                    ProductID:            dodopayments.F(newProductID),
                    Quantity:             dodopayments.F(int64(1)),
                    ProrationBillingMode: dodopayments.F(dodopayments.UpdateSubscriptionPlanReqProrationBillingModeDifferenceImmediately),
                },
            },
        )
        if err != nil {
            return nil, err
        }
        
        return map[string]interface{}{
            "immediate_charge": preview.ImmediateCharge.Summary,
            "new_plan":         preview.NewPlan,
            "effective_at":     preview.ImmediateCharge.EffectiveAt,
        }, nil
    }
    ```
  </Tab>
</Tabs>

### Execute the Upgrade

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    async function upgradeSubscription(
      subscriptionId: string,
      newProductId: string,
      prorationMode: 'prorated_immediately' | 'difference_immediately' | 'full_immediately' = 'difference_immediately'
    ) {
      const result = await client.subscriptions.changePlan(subscriptionId, {
        product_id: newProductId,
        quantity: 1,
        proration_billing_mode: prorationMode
      });

      return {
        status: result.status,
        subscriptionId: result.subscription_id,
        paymentId: result.payment_id,
        invoiceId: result.invoice_id
      };
    }

    // Upgrade from Basic ($30) to Pro ($80)
    // With difference_immediately: charges $50 instantly
    const upgrade = await upgradeSubscription('sub_123', 'prod_pro_plan');
    console.log('Upgrade status:', upgrade.status);
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    def upgrade_subscription(
        subscription_id: str,
        new_product_id: str,
        proration_mode: str = "difference_immediately"
    ):
        result = client.subscriptions.change_plan(
            subscription_id=subscription_id,
            product_id=new_product_id,
            quantity=1,
            proration_billing_mode=proration_mode
        )
        
        return {
            "status": result.status,
            "subscription_id": result.subscription_id,
            "payment_id": result.payment_id,
            "invoice_id": result.invoice_id
        }

    # Upgrade from Basic ($30) to Pro ($80)
    # With difference_immediately: charges $50 instantly
    upgrade = upgrade_subscription("sub_123", "prod_pro_plan")
    print(f"Upgrade status: {upgrade['status']}")
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    func upgradeSubscription(
        subscriptionID string,
        newProductID string,
        prorationMode dodopayments.UpdateSubscriptionPlanReqProrationBillingMode,
    ) error {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        // ChangePlan returns no response body; a nil error means the change succeeded.
        err := client.Subscriptions.ChangePlan(
            context.TODO(),
            subscriptionID,
            dodopayments.SubscriptionChangePlanParams{
                UpdateSubscriptionPlanReq: dodopayments.UpdateSubscriptionPlanReqParam{
                    ProductID:            dodopayments.F(newProductID),
                    Quantity:             dodopayments.F(int64(1)),
                    ProrationBillingMode: dodopayments.F(prorationMode),
                },
            },
        )
        
        return err
    }

    // Upgrade from Basic ($30) to Pro ($80)
    // With DifferenceImmediately: charges $50 instantly
    err := upgradeSubscription(
        "sub_123",
        "prod_pro_plan",
        dodopayments.UpdateSubscriptionPlanReqProrationBillingModeDifferenceImmediately,
    )
    if err != nil {
        panic(err)
    }
    fmt.Println("Upgrade succeeded")
    ```
  </Tab>
</Tabs>

### Proration Modes

اختر كيف يتم فوترة العملاء عند الترقية:

| Mode                     | Behavior                                                | Best For                          |
| ------------------------ | ------------------------------------------------------- | --------------------------------- |
| `difference_immediately` | يخصم فرق السعر فورًا ($30→$80 = \$50)                   | الترقيات المباشرة                 |
| `prorated_immediately`   | يخصم بناءً على الوقت المتبقي في دورة الفوترة            | الفوترة العادلة المبنية على الوقت |
| `full_immediately`       | يخصم السعر الكامل للخطة الجديدة، متجاهلًا الوقت المتبقي | إعادة ضبط دورة الفوترة            |

<Tip>
  استخدم `difference_immediately` لتدفقات الترقيات البسيطة. استخدم `prorated_immediately` عندما تريد احتساب الوقت غير المستخدم في الخطة الحالية.
</Tip>

## Cross-Sells

أضف منتجات تكميلية للعملاء الحاليين دون الحاجة إلى إعادة إدخال تفاصيل الدفع.

```mermaid theme={null}
flowchart LR
    A[View Product] --> B{Existing Customer?}
    B -->|Yes| C[One-Click Buy] --> E[Deliver]
    B -->|No| D[Standard Checkout] --> E
```

### Implementation

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    async function createCrossSell(
      customerId: string,
      paymentMethodId: string,
      productId: string,
      quantity: number = 1
    ) {
      // Create a one-time payment using saved payment method
      const payment = await client.payments.create({
        product_cart: [
          {
            product_id: productId,
            quantity: quantity
          }
        ],
        customer_id: customerId,
        payment_method_id: paymentMethodId,
        return_url: 'https://yourapp.com/purchase-complete',
        metadata: {
          purchase_type: 'cross_sell',
          source: 'product_recommendation'
        }
      });

      return payment;
    }

    // Example: Customer bought a course, offer related ebook
    async function offerRelatedProduct(customerId: string, relatedProductId: string) {
      const methods = await client.customers.retrievePaymentMethods(customerId);
      
      if (methods.length === 0) {
        // Fall back to standard checkout
        return client.checkoutSessions.create({
          product_cart: [{ product_id: relatedProductId, quantity: 1 }],
          customer: { customer_id: customerId },
          return_url: 'https://yourapp.com/purchase-complete'
        });
      }

      // One-click purchase
      return createCrossSell(customerId, methods[0].payment_method_id, relatedProductId);
    }
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    def create_cross_sell(
        customer_id: str,
        payment_method_id: str,
        product_id: str,
        quantity: int = 1
    ):
        """Create a one-time payment using saved payment method."""
        
        payment = client.payments.create(
            product_cart=[
                {
                    "product_id": product_id,
                    "quantity": quantity
                }
            ],
            customer_id=customer_id,
            payment_method_id=payment_method_id,
            return_url="https://yourapp.com/purchase-complete",
            metadata={
                "purchase_type": "cross_sell",
                "source": "product_recommendation"
            }
        )
        
        return payment

    def offer_related_product(customer_id: str, related_product_id: str):
        """Offer related product with one-click purchase if possible."""
        
        methods = client.customers.retrieve_payment_methods(customer_id)
        
        if not methods:
            # Fall back to standard checkout
            return client.checkout_sessions.create(
                product_cart=[{"product_id": related_product_id, "quantity": 1}],
                customer={"customer_id": customer_id},
                return_url="https://yourapp.com/purchase-complete"
            )
        
        # One-click purchase
        return create_cross_sell(customer_id, methods[0].payment_method_id, related_product_id)
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    func createCrossSell(
        customerID string,
        paymentMethodID string,
        productID string,
        quantity int64,
    ) (*dodopayments.PaymentNewResponse, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        payment, err := client.Payments.New(context.TODO(), dodopayments.PaymentNewParams{
            ProductCart: dodopayments.F([]dodopayments.OneTimeProductCartItemParam{
                {
                    ProductID: dodopayments.F(productID),
                    Quantity:  dodopayments.F(quantity),
                },
            }),
            Customer: dodopayments.F[dodopayments.CustomerRequestUnionParam](
                dodopayments.AttachExistingCustomerParam{CustomerID: dodopayments.F(customerID)},
            ),
            Billing: dodopayments.F(dodopayments.BillingAddressParam{
                Country: dodopayments.F(dodopayments.CountryCodeUs),
                City:    dodopayments.F("San Francisco"),
                State:   dodopayments.F("CA"),
                Street:  dodopayments.F("1 Market St"),
                Zipcode: dodopayments.F("94105"),
            }),
            PaymentMethodID: dodopayments.F(paymentMethodID),
            ReturnURL:       dodopayments.F("https://yourapp.com/purchase-complete"),
            Metadata: dodopayments.F(map[string]string{
                "purchase_type": "cross_sell",
                "source":        "product_recommendation",
            }),
        })
        
        return payment, err
    }

    func offerRelatedProduct(customerID string, relatedProductID string) (interface{}, error) {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        resp, err := client.Customers.GetPaymentMethods(context.TODO(), customerID)
        if err != nil {
            return nil, err
        }
        
        if len(resp.Items) == 0 {
            // Fall back to standard checkout
            return client.CheckoutSessions.New(context.TODO(), dodopayments.CheckoutSessionNewParams{
                CheckoutSessionRequest: dodopayments.CheckoutSessionRequestParam{
                    ProductCart: dodopayments.F([]dodopayments.ProductItemReqParam{
                        {ProductID: dodopayments.F(relatedProductID), Quantity: dodopayments.F(int64(1))},
                    }),
                    Customer: dodopayments.F[dodopayments.CustomerRequestUnionParam](
                        dodopayments.AttachExistingCustomerParam{CustomerID: dodopayments.F(customerID)},
                    ),
                    ReturnURL: dodopayments.F("https://yourapp.com/purchase-complete"),
                },
            })
        }
        
        // One-click purchase
        return createCrossSell(customerID, resp.Items[0].PaymentMethodID, relatedProductID, 1)
    }
    ```
  </Tab>
</Tabs>

## Subscription Downgrades

عندما يرغب العملاء في الانتقال إلى خطة أقل، تعامل مع الانتقال بسلاسة باستخدام الاعتمادات التلقائية.

### How Downgrades Work

1. يطلب العميل تخفيضًا (Pro → Basic)
2. يحسب النظام القيمة المتبقية في الخطة الحالية
3. تُضاف اعتمادات للاشتراك للتجديدات المستقبلية
4. ينتقل العميل إلى الخطة الجديدة فورًا

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    async function downgradeSubscription(
      subscriptionId: string,
      newProductId: string
    ) {
      // Preview the downgrade first
      const preview = await client.subscriptions.previewChangePlan(subscriptionId, {
        product_id: newProductId,
        quantity: 1,
        proration_billing_mode: 'difference_immediately'
      });

      console.log('Credit to be applied:', preview.credit_amount);

      // Execute the downgrade
      const result = await client.subscriptions.changePlan(subscriptionId, {
        product_id: newProductId,
        quantity: 1,
        proration_billing_mode: 'difference_immediately'
      });

      // Credits are automatically applied to future renewals
      return result;
    }

    // Downgrade from Pro ($80) to Basic ($30)
    // $50 credit added to subscription, auto-applied on next renewal
    const downgrade = await downgradeSubscription('sub_123', 'prod_basic_plan');
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    def downgrade_subscription(subscription_id: str, new_product_id: str):
        # Preview the downgrade first
        preview = client.subscriptions.preview_change_plan(
            subscription_id=subscription_id,
            product_id=new_product_id,
            quantity=1,
            proration_billing_mode="difference_immediately"
        )
        
        print(f"Credit to be applied: {preview.credit_amount}")
        
        # Execute the downgrade
        result = client.subscriptions.change_plan(
            subscription_id=subscription_id,
            product_id=new_product_id,
            quantity=1,
            proration_billing_mode="difference_immediately"
        )
        
        # Credits are automatically applied to future renewals
        return result

    # Downgrade from Pro ($80) to Basic ($30)
    # $50 credit added to subscription, auto-applied on next renewal
    downgrade = downgrade_subscription("sub_123", "prod_basic_plan")
    ```
  </Tab>

  <Tab title="Go">
    ```go theme={null}
    func downgradeSubscription(subscriptionID string, newProductID string) error {
        client := dodopayments.NewClient(
            option.WithBearerToken(os.Getenv("DODO_PAYMENTS_API_KEY")),
        )
        
        // Preview the downgrade first
        preview, err := client.Subscriptions.PreviewChangePlan(
            context.TODO(),
            subscriptionID,
            dodopayments.SubscriptionPreviewChangePlanParams{
                UpdateSubscriptionPlanReq: dodopayments.UpdateSubscriptionPlanReqParam{
                    ProductID:            dodopayments.F(newProductID),
                    Quantity:             dodopayments.F(int64(1)),
                    ProrationBillingMode: dodopayments.F(dodopayments.UpdateSubscriptionPlanReqProrationBillingModeDifferenceImmediately),
                },
            },
        )
        if err != nil {
            return err
        }
        
        fmt.Printf("Customer credits to be applied: %v\n", preview.ImmediateCharge.Summary.CustomerCredits)
        
        // Execute the downgrade (returns no response body; nil error means success)
        return client.Subscriptions.ChangePlan(
            context.TODO(),
            subscriptionID,
            dodopayments.SubscriptionChangePlanParams{
                UpdateSubscriptionPlanReq: dodopayments.UpdateSubscriptionPlanReqParam{
                    ProductID:            dodopayments.F(newProductID),
                    Quantity:             dodopayments.F(int64(1)),
                    ProrationBillingMode: dodopayments.F(dodopayments.UpdateSubscriptionPlanReqProrationBillingModeDifferenceImmediately),
                },
            },
        )
    }
    ```
  </Tab>
</Tabs>

<Info>
  تُعتبر الاعتمادات من التخفيضات باستخدام `difference_immediately` مرتبطة بالاشتراك ويتم تطبيقها تلقائيًا على عمليات التجديد المستقبلية. وهي مميزة عن ال\[[Credit-Based Billing](/features/credit-based-billing)] الاستحقاقات.
</Info>

## Complete Example: Post-Purchase Upsell Flow

إليك تنفيذًا كاملاً يوضح كيفية عرض ترقية بعد عملية شراء ناجحة:

<Tabs>
  <Tab title="TypeScript">
    ```typescript theme={null}
    import DodoPayments from 'dodopayments';
    import express from 'express';

    const client = new DodoPayments({
      bearerToken: process.env.DODO_PAYMENTS_API_KEY,
      environment: 'live_mode',
    });

    const app = express();

    // Store for tracking upsell eligibility (use your database in production)
    const eligibleUpsells = new Map<string, { customerId: string; productId: string }>();

    // Webhook handler for initial purchase success
    app.post('/webhooks/dodo', express.raw({ type: 'application/json' }), async (req, res) => {
      const event = JSON.parse(req.body.toString());
      
      switch (event.type) {
        case 'payment.succeeded':
          // Check if customer is eligible for upsell
          const customerId = event.data.customer_id;
          const productId = event.data.product_id;
          
          // Define upsell rules (e.g., bought Basic, offer Pro)
          const upsellProduct = getUpsellProduct(productId);
          
          if (upsellProduct) {
            eligibleUpsells.set(customerId, {
              customerId,
              productId: upsellProduct
            });
          }
          break;
          
        case 'payment.failed':
          console.log('Payment failed:', event.data.payment_id);
          // Handle failed upsell payment
          break;
      }
      
      res.json({ received: true });
    });

    // API endpoint to check upsell eligibility
    app.get('/api/upsell/:customerId', async (req, res) => {
      const { customerId } = req.params;
      const upsell = eligibleUpsells.get(customerId);
      
      if (!upsell) {
        return res.json({ eligible: false });
      }
      
      // Get payment methods
      const methods = await client.customers.retrievePaymentMethods(customerId);
      
      if (methods.length === 0) {
        return res.json({ eligible: false, reason: 'no_payment_method' });
      }
      
      // Get product details for display
      const product = await client.products.retrieve(upsell.productId);
      
      res.json({
        eligible: true,
        product: {
          id: product.product_id,
          name: product.name,
          price: product.price,
          currency: product.currency
        },
        paymentMethodId: methods[0].payment_method_id
      });
    });

    // API endpoint to accept upsell
    app.post('/api/upsell/:customerId/accept', async (req, res) => {
      const { customerId } = req.params;
      const upsell = eligibleUpsells.get(customerId);
      
      if (!upsell) {
        return res.status(400).json({ error: 'No upsell available' });
      }
      
      try {
        const methods = await client.customers.retrievePaymentMethods(customerId);
        
        // Create one-click purchase
        const session = await client.checkoutSessions.create({
          product_cart: [{ product_id: upsell.productId, quantity: 1 }],
          customer: { customer_id: customerId },
          payment_method_id: methods[0].payment_method_id,
          confirm: true,
          return_url: `${process.env.APP_URL}/upsell-success`,
          feature_flags: { redirect_immediately: true },
          metadata: { upsell: 'true', source: 'post_purchase' }
        });
        
        // Clear the upsell offer
        eligibleUpsells.delete(customerId);
        
        res.json({ success: true, sessionId: session.session_id });
      } catch (error) {
        console.error('Upsell failed:', error);
        res.status(500).json({ error: 'Upsell processing failed' });
      }
    });

    // Helper function to determine upsell product
    function getUpsellProduct(purchasedProductId: string): string | null {
      const upsellMap: Record<string, string> = {
        'prod_basic_plan': 'prod_pro_plan',
        'prod_starter_course': 'prod_complete_bundle',
        'prod_single_license': 'prod_team_license'
      };
      
      return upsellMap[purchasedProductId] || null;
    }

    app.listen(3000);
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    import os
    from flask import Flask, request, jsonify
    from dodopayments import DodoPayments

    client = DodoPayments(
        bearer_token=os.environ.get("DODO_PAYMENTS_API_KEY"),
        environment="live_mode",
    )

    app = Flask(__name__)

    # Store for tracking upsell eligibility (use your database in production)
    eligible_upsells = {}

    @app.route('/webhooks/dodo', methods=['POST'])
    def webhook_handler():
        event = request.json
        
        if event['type'] == 'payment.succeeded':
            # Check if customer is eligible for upsell
            customer_id = event['data']['customer_id']
            product_id = event['data']['product_id']
            
            # Define upsell rules
            upsell_product = get_upsell_product(product_id)
            
            if upsell_product:
                eligible_upsells[customer_id] = {
                    'customer_id': customer_id,
                    'product_id': upsell_product
                }
        
        elif event['type'] == 'payment.failed':
            print(f"Payment failed: {event['data']['payment_id']}")
        
        return jsonify({'received': True})

    @app.route('/api/upsell/<customer_id>', methods=['GET'])
    def check_upsell(customer_id):
        upsell = eligible_upsells.get(customer_id)
        
        if not upsell:
            return jsonify({'eligible': False})
        
        # Get payment methods
        methods = client.customers.retrieve_payment_methods(customer_id)
        
        if not methods:
            return jsonify({'eligible': False, 'reason': 'no_payment_method'})
        
        # Get product details for display
        product = client.products.retrieve(upsell['product_id'])
        
        return jsonify({
            'eligible': True,
            'product': {
                'id': product.product_id,
                'name': product.name,
                'price': product.price,
                'currency': product.currency
            },
            'payment_method_id': methods[0].payment_method_id
        })

    @app.route('/api/upsell/<customer_id>/accept', methods=['POST'])
    def accept_upsell(customer_id):
        upsell = eligible_upsells.get(customer_id)
        
        if not upsell:
            return jsonify({'error': 'No upsell available'}), 400
        
        try:
            methods = client.customers.retrieve_payment_methods(customer_id)
            
            # Create one-click purchase
            session = client.checkout_sessions.create(
                product_cart=[{'product_id': upsell['product_id'], 'quantity': 1}],
                customer={'customer_id': customer_id},
                payment_method_id=methods[0].payment_method_id,
                confirm=True,
                return_url=f"{os.environ['APP_URL']}/upsell-success",
                feature_flags={'redirect_immediately': True},
                metadata={'upsell': 'true', 'source': 'post_purchase'}
            )
            
            # Clear the upsell offer
            del eligible_upsells[customer_id]
            
            return jsonify({'success': True, 'session_id': session.session_id})
        
        except Exception as error:
            print(f"Upsell failed: {error}")
            return jsonify({'error': 'Upsell processing failed'}), 500

    def get_upsell_product(purchased_product_id: str) -> str:
        """Determine upsell product based on purchased product."""
        upsell_map = {
            'prod_basic_plan': 'prod_pro_plan',
            'prod_starter_course': 'prod_complete_bundle',
            'prod_single_license': 'prod_team_license'
        }
        return upsell_map.get(purchased_product_id)

    if __name__ == '__main__':
        app.run(port=3000)
    ```
  </Tab>
</Tabs>

## Best Practices

<AccordionGroup>
  <Accordion title="Time Your Upsells Strategically">
    أفضل وقت لعرض ترقية هو فور إتمام عملية شراء ناجحة عندما يكون العملاء في ذهن الشراء. لحظات فعالة أخرى:

    * بعد بلوغ معالم استخدام الميزة
    * عند الاقتراب من حدود الخطة
    * عند إكمال عملية الإعداد
  </Accordion>

  <Accordion title="Validate Payment Method Eligibility">
    قبل محاولة خصم بنقرة واحدة، تحقق من طريقة الدفع:

    * هل تتوافق مع عملة المنتج
    * هل لم تنتهِ صلاحيتها
    * هل تنتمي إلى العميل

    سوف تتحقق واجهة برمجة التطبيقات من ذلك، لكن الفحص المسبق يُحسن تجربة المستخدم.
  </Accordion>

  <Accordion title="Handle Failures Gracefully">
    عندما تفشل عمليات الخصم بنقرة واحدة:

    1. العودة إلى تدفق الدفع القياسي
    2. إخطار العميل برسالة واضحة
    3. عرض تحديث طريقة الدفع
    4. عدم تكرار المحاولات الفاشلة
  </Accordion>

  <Accordion title="Provide Clear Value Proposition">
    تحقق من أن العملاء يفهمون القيمة لتحقيق أفضل تحويل:

    * أظهر ما سيحصلون عليه مقابل الخطة الحالية
    * أبرز فرق السعر، وليس السعر الكامل
    * استخدم الدليل الاجتماعي (مثل «الترقية الأكثر شعبية»)
  </Accordion>

  <Accordion title="Respect Customer Choice">
    * دائمًا قدّم طريقة سهلة للرفض
    * لا تعرض نفس الترقية بعد الرفض مرة أخرى
    * تتبع وحلل الترقيات التي تتحول لتحسين العروض
  </Accordion>
</AccordionGroup>

## Webhooks to Monitor

تابع هذه الأحداث في Webhooks لتدفقات الترقيات والتخفيضات:

| Event                       | Trigger                              | Action                                                  |
| --------------------------- | ------------------------------------ | ------------------------------------------------------- |
| `payment.succeeded`         | اكتمال دفعة الترقية/البيع المتقاطع   | تسليم المنتج، تحديث الوصول                              |
| `payment.failed`            | فشل خصم بنقرة واحدة                  | عرض خطأ، عرض إعادة المحاولة أو العودة إلى الخيار البديل |
| `subscription.plan_changed` | اكتمال الترقية/التخفيض               | تحديث الميزات، إرسال تأكيد                              |
| `subscription.active`       | إعادة تنشيط الاشتراك بعد تغيير الخطة | منح الوصول إلى المستوى الجديد                           |

<Card title="Webhook Integration Guide" icon="webhook" href="/developer-resources/webhooks">
  تعرّف على كيفية إعداد والتحقق من نقاط نهاية Webhook.
</Card>

## Related Resources

<CardGroup cols={2}>
  <Card title="Subscription Upgrade Guide" icon="arrows-rotate" href="/developer-resources/subscription-upgrade-downgrade">
    دليل مفصل حول تغييرات الخطط، أوضاع التوزيع، والتعامل مع الإخفاقات.
  </Card>

  <Card title="Checkout Sessions" icon="cart-shopping" href="/developer-resources/checkout-session">
    مرجع كامل لإنشاء جلسات الدفع بكافة الخيارات.
  </Card>

  <Card title="Customer Payment Methods API" icon="credit-card" href="/api-reference/customers/get-customer-payment-methods">
    مرجع واجهة برمجة التطبيقات لعرض طرق دفع العملاء.
  </Card>

  <Card title="Add-ons" icon="puzzle-piece" href="/features/addons">
    حسّن الاشتراكات بإضافات مرنة لتحقيق إيرادات إضافية.
  </Card>
</CardGroup>
