> ## Documentation Index > Fetch the complete documentation index at: https://developers.appstle.com/llms.txt > Use this file to discover all available pages before exploring further. # Update product variant in subscription contract > Replaces an existing product variant with a new variant in a subscription contract. This allows customers to swap products in their membership while maintaining their subscription. **Key Features:** - **Product Swapping**: Replace any line item's variant with a different variant - **Quantity Preservation**: Maintains the same quantity after variant swap - **Price Updates**: New variant pricing is applied automatically - **Flexible Identification**: Identify old variant by lineId OR variantId - **Activity Logging**: All variant changes are logged for audit trail **Identification Methods:** You can identify the old variant using either: - **oldLineId**: The Shopify line item ID from the subscription contract - **oldVariantId**: The Shopify product variant ID At least one of these must be provided. **Common Use Cases:** - Customer wants to change product flavor/color/size in their membership - Swap discontinued products with new alternatives - Change product preferences mid-subscription - Update seasonal product selections - Replace out-of-stock variants with alternatives **Important Notes:** - **Immediate Effect**: Variant change applies to the next billing cycle - **Validation**: System validates new variant exists and is available - **Same Product**: Old and new variants can be from different products - **Price Changes**: Customer is charged the new variant's price **Variant ID Format:** - Accepts both numeric IDs and GraphQL IDs (gid://shopify/ProductVariant/...) - System automatically converts to correct format **Authentication:** Requires API key authentication via X-API-Key header or api_key parameter ## OpenAPI ````yaml /memberships/admin-api-swagger.json put /api/external/v2/subscription-contract-update-variant openapi: 3.0.1 info: description: >- Comprehensive API documentation for managing memberships, payments, and related operations. These APIs allow you to programmatically manage membership lifecycles, handle payments, configure products, and integrate membership functionality into your applications. title: Admin APIs version: 0.0.1 servers: - url: https://membership-admin.appstle.com security: [] tags: - description: >- APIs for managing Shopify delivery profiles, shipping rates, zones, and free shipping configuration for subscription memberships name: Shipping & Delivery Profiles - description: >- APIs for retrieving historical discount code usage and redemption information for membership contracts name: Customer Discount History - description: >- APIs for managing membership cancellation flow settings including retention offers, survey questions, and cancel confirmation screens name: Cancellation Flow Configuration - description: >- APIs for managing membership billing attempts, recurring orders, payment retries, order history, and order skipping name: Billing & Orders - description: >- APIs for managing one-time product additions to upcoming subscription orders, including adding, retrieving, and removing one-off items name: One-Time Add-Ons - description: >- APIs for managing membership/subscription plan groups, including creating plans, configuring discounts, billing intervals, and assigning products to plans name: Membership Plans - description: >- APIs for managing subscription product bundles, bundle configurations, item grouping, and bundle-specific discount codes name: Product Bundles - description: >- APIs for retrieving custom CSS styles applied to subscription widgets and customer portal for theme customization name: Custom CSS Styling - description: >- APIs for managing customer portal settings including UI customization, text labels, feature toggles, and branding options for the member self-service portal name: Customer Portal Configuration - description: >- APIs for managing membership/subscription contracts including creation, updates, status changes, line items, discounts, and billing operations name: Membership Contracts - description: >- APIs for managing subscription bundle configuration settings including bundle behavior, pricing rules, and display options name: Bundle Settings - description: >- APIs for managing customer payment methods, payment tokens, and payment method retrieval for subscriptions name: Customer Payment Methods - description: >- APIs for retrieving product swap/substitution options allowing members to exchange subscription items based on configured swap rules and variant groups name: Product Swap Rules - description: >- APIs for retrieving product catalog, variants, pricing, and inventory information for subscription memberships. name: Product & Inventory Data - description: >- APIs for managing shop-level membership settings, configuration, and general store information. name: Shop Settings - description: >- APIs for performing bulk/mass operations on multiple membership contracts including status updates, product replacements, and billing date changes. name: Bulk Operations paths: /api/external/v2/subscription-contract-update-variant: put: tags: - Membership Contracts summary: Update product variant in subscription contract description: >- Replaces an existing product variant with a new variant in a subscription contract. This allows customers to swap products in their membership while maintaining their subscription. **Key Features:** - **Product Swapping**: Replace any line item's variant with a different variant - **Quantity Preservation**: Maintains the same quantity after variant swap - **Price Updates**: New variant pricing is applied automatically - **Flexible Identification**: Identify old variant by lineId OR variantId - **Activity Logging**: All variant changes are logged for audit trail **Identification Methods:** You can identify the old variant using either: - **oldLineId**: The Shopify line item ID from the subscription contract - **oldVariantId**: The Shopify product variant ID At least one of these must be provided. **Common Use Cases:** - Customer wants to change product flavor/color/size in their membership - Swap discontinued products with new alternatives - Change product preferences mid-subscription - Update seasonal product selections - Replace out-of-stock variants with alternatives **Important Notes:** - **Immediate Effect**: Variant change applies to the next billing cycle - **Validation**: System validates new variant exists and is available - **Same Product**: Old and new variants can be from different products - **Price Changes**: Customer is charged the new variant's price **Variant ID Format:** - Accepts both numeric IDs and GraphQL IDs (gid://shopify/ProductVariant/...) - System automatically converts to correct format **Authentication:** Requires API key authentication via X-API-Key header or api_key parameter operationId: updateVariantV2 parameters: - description: Subscription contract ID example: 12345 in: query name: contractId required: true schema: format: int64 type: integer - description: API Key (Deprecated - Use Header X-API-Key instead) in: query name: api_key required: false schema: type: string - in: header name: X-API-Key required: false schema: type: string - description: Line item ID to replace (provide either oldLineId or oldVariantId) example: gid://shopify/SubscriptionLine/123 in: query name: oldLineId required: false schema: type: string - description: Old variant ID to replace (provide either oldLineId or oldVariantId) example: 40123456789 in: query name: oldVariantId required: false schema: type: string - description: New variant ID to use as replacement example: 40987654321 in: query name: newVariantId required: true schema: type: string - description: Skip billing on plan change (no charge or refund) example: false in: query name: skipBilling required: false schema: default: false type: boolean responses: '200': content: application/json: schema: $ref: '#/components/schemas/SubscriptionContract' description: Variant successfully updated in subscription contract '400': content: application/json: examples: Missing old variant: description: Missing old variant value: detail: 'UserGeneratedError: Old variant not provided' status: 400 title: Bad Request Same variant error: description: Same variant error value: detail: >- UserGeneratedError:New variant cannot be the same as old variant status: 400 title: Bad Request description: Invalid request - validation failed '401': content: '*/*': schema: $ref: '#/components/schemas/SubscriptionContract' description: Authentication required - invalid or missing API key '404': content: '*/*': schema: $ref: '#/components/schemas/SubscriptionContract' description: Subscription contract or variant not found '500': content: '*/*': schema: $ref: '#/components/schemas/SubscriptionContract' description: Shopify API error during variant update components: schemas: SubscriptionContract: properties: billingAttempts: $ref: '#/components/schemas/BillingAttempts' billingPolicy: $ref: '#/components/schemas/BillingPolicy' createdAt: type: object customAttributes: items: $ref: '#/components/schemas/CustomAttribute1' type: array customer: $ref: '#/components/schemas/Customer' customerPaymentMethod: $ref: '#/components/schemas/CustomerPaymentMethod' deliveryMethod: $ref: '#/components/schemas/DeliveryMethod' deliveryPolicy: $ref: '#/components/schemas/DeliveryPolicy' deliveryPrice: $ref: '#/components/schemas/DeliveryPrice' discounts: $ref: '#/components/schemas/Discounts' get__typename: type: string id: type: string lastPaymentStatus: enum: - SUCCEEDED - FAILED - $UNKNOWN type: string lines: $ref: '#/components/schemas/Lines' nextBillingDate: type: object note: type: string originOrder: $ref: '#/components/schemas/OriginOrder' status: enum: - ACTIVE - PAUSED - CANCELLED - EXPIRED - FAILED - $UNKNOWN type: string updatedAt: type: object type: object BillingAttempts: properties: get__typename: type: string nodes: items: $ref: '#/components/schemas/Node3' type: array type: object BillingPolicy: properties: anchors: items: $ref: '#/components/schemas/Anchor' type: array get__typename: type: string interval: enum: - DAY - WEEK - MONTH - YEAR - $UNKNOWN type: string intervalCount: format: int32 type: integer maxCycles: format: int32 type: integer minCycles: format: int32 type: integer type: object CustomAttribute1: properties: get__typename: type: string key: type: string value: type: string type: object Customer: properties: displayName: type: string email: deprecated: true type: string firstName: type: string get__typename: type: string id: type: string lastName: type: string phone: deprecated: true type: string type: object CustomerPaymentMethod: properties: get__typename: type: string id: type: string instrument: $ref: '#/components/schemas/Instrument' revokedAt: type: object revokedReason: enum: - AUTHORIZE_NET_GATEWAY_NOT_ENABLED - AUTHORIZE_NET_RETURNED_NO_PAYMENT_METHOD - FAILED_TO_UPDATE_CREDIT_CARD - STRIPE_API_AUTHENTICATION_ERROR - STRIPE_API_INVALID_REQUEST_ERROR - STRIPE_GATEWAY_NOT_ENABLED - STRIPE_RETURNED_NO_PAYMENT_METHOD - STRIPE_PAYMENT_METHOD_NOT_CARD - BRAINTREE_API_AUTHENTICATION_ERROR - BRAINTREE_GATEWAY_NOT_ENABLED - BRAINTREE_RETURNED_NO_PAYMENT_METHOD - BRAINTREE_PAYMENT_METHOD_NOT_CARD - PAYMENT_METHOD_VERIFICATION_FAILED - THREE_D_SECURE_FLOW_IN_VERIFICATION_NOT_IMPLEMENTED - MANUALLY_REVOKED - FAILED_TO_RETRIEVE_BILLING_ADDRESS - MERGED - CUSTOMER_REDACTED - TOO_MANY_CONSECUTIVE_FAILURES - CVV_ATTEMPTS_LIMIT_EXCEEDED - $UNKNOWN type: string type: object DeliveryMethod: properties: additionalInformation: $ref: '#/components/schemas/AdditionalInformation' brandedPromise: $ref: '#/components/schemas/BrandedPromise' get__typename: type: string id: type: string maxDeliveryDateTime: type: object methodType: enum: - SHIPPING - PICK_UP - NONE - RETAIL - LOCAL - PICKUP_POINT - $UNKNOWN type: string minDeliveryDateTime: type: object serviceCode: type: string type: object DeliveryPolicy: properties: anchors: items: $ref: '#/components/schemas/Anchor1' type: array get__typename: type: string interval: enum: - DAY - WEEK - MONTH - YEAR - $UNKNOWN type: string intervalCount: format: int32 type: integer type: object DeliveryPrice: properties: amount: type: object currencyCode: enum: - USD - EUR - GBP - CAD - AFN - ALL - DZD - AOA - ARS - AMD - AWG - AUD - BBD - AZN - BDT - BSD - BHD - BIF - BYN - BZD - BMD - BTN - BAM - BRL - BOB - BWP - BND - BGN - MMK - KHR - CVE - KYD - XAF - CLP - CNY - COP - KMF - CDF - CRC - HRK - CZK - DKK - DJF - DOP - XCD - EGP - ERN - ETB - FKP - XPF - FJD - GIP - GMD - GHS - GTQ - GYD - GEL - GNF - HTG - HNL - HKD - HUF - ISK - INR - IDR - ILS - IRR - IQD - JMD - JPY - JEP - JOD - KZT - KES - KID - KWD - KGS - LAK - LVL - LBP - LSL - LRD - LYD - LTL - MGA - MKD - MOP - MWK - MVR - MRU - MXN - MYR - MUR - MDL - MAD - MNT - MZN - NAD - NPR - ANG - NZD - NIO - NGN - NOK - OMR - PAB - PKR - PGK - PYG - PEN - PHP - PLN - QAR - RON - RUB - RWF - WST - SHP - SAR - RSD - SCR - SLL - SGD - SDG - SOS - SYP - ZAR - KRW - SSP - SBD - LKR - SRD - SZL - SEK - CHF - TWD - THB - TJS - TZS - TOP - TTD - TND - TRY - TMT - UGX - UAH - AED - UYU - UZS - VUV - VES - VND - XOF - YER - ZMW - USDC - BYR - STD - STN - VED - VEF - XXX - $UNKNOWN type: string get__typename: type: string type: object Discounts: properties: get__typename: type: string nodes: items: $ref: '#/components/schemas/Node2' type: array pageInfo: $ref: '#/components/schemas/PageInfo2' type: object Lines: properties: get__typename: type: string nodes: items: $ref: '#/components/schemas/Node' type: array pageInfo: $ref: '#/components/schemas/PageInfo' type: object OriginOrder: properties: fulfillmentOrders: $ref: '#/components/schemas/FulfillmentOrders' get__typename: type: string id: type: string name: type: string type: object Node3: properties: completedAt: type: object createdAt: type: object get__typename: type: string id: type: string idempotencyKey: type: string ready: deprecated: true type: boolean type: object Anchor: properties: cutoffDay: format: int32 type: integer day: format: int32 type: integer get__typename: type: string month: format: int32 type: integer type: enum: - WEEKDAY - MONTHDAY - YEARDAY - $UNKNOWN type: string type: object Instrument: properties: get__typename: type: string type: object AdditionalInformation: properties: get__typename: type: string instructions: type: string type: object BrandedPromise: properties: get__typename: type: string handle: type: string name: type: string type: object Anchor1: properties: cutoffDay: format: int32 type: integer day: format: int32 type: integer get__typename: type: string month: format: int32 type: integer type: enum: - WEEKDAY - MONTHDAY - YEARDAY - $UNKNOWN type: string type: object Node2: properties: createdAt: type: object deliveredAt: type: object displayStatus: enum: - ATTEMPTED_DELIVERY - CANCELED - CONFIRMED - DELAYED - DELIVERED - FAILURE - FULFILLED - CARRIER_PICKED_UP - IN_TRANSIT - LABEL_PRINTED - LABEL_PURCHASED - LABEL_VOIDED - MARKED_AS_FULFILLED - NOT_DELIVERED - OUT_FOR_DELIVERY - READY_FOR_PICKUP - PICKED_UP - SUBMITTED - $UNKNOWN type: string estimatedDeliveryAt: type: object get__typename: type: string id: type: string inTransitAt: type: object name: type: string requiresShipping: type: boolean service: $ref: '#/components/schemas/Service' status: enum: - PENDING - OPEN - SUCCESS - CANCELLED - ERROR - FAILURE - $UNKNOWN type: string trackingInfo: items: $ref: '#/components/schemas/TrackingInfo' type: array type: object PageInfo2: properties: endCursor: type: string get__typename: type: string hasNextPage: type: boolean hasPreviousPage: type: boolean startCursor: type: string type: object Node: properties: get__typename: type: string type: object PageInfo: properties: endCursor: type: string get__typename: type: string hasNextPage: type: boolean hasPreviousPage: type: boolean startCursor: type: string type: object FulfillmentOrders: properties: get__typename: type: string nodes: items: $ref: '#/components/schemas/Node' type: array pageInfo: $ref: '#/components/schemas/PageInfo2' type: object Service: properties: get__typename: type: string handle: type: string serviceName: type: string type: enum: - GIFT_CARD - MANUAL - THIRD_PARTY - $UNKNOWN type: string type: object TrackingInfo: properties: company: type: string get__typename: type: string number: type: string url: type: object type: object ````