# Update multiple properties of a subscription line item

Comprehensive endpoint for updating a subscription line item's quantity, price, product variant, and/or selling plan in a single API call. Changes are applied intelligently - only modified values trigger updates.

Key Features:
- Update any combination of: quantity, price, variant, or selling plan
- Intelligent change detection - only updates what's different
- Automatic handling of prepaid subscription pricing
- Preserves existing discount cycles when updating price
- Partial success allowed - some updates may fail while others succeed
- Each change creates separate activity log entries

Prepaid Subscription Handling:
For prepaid subscriptions (billing interval > delivery interval):
- When isPricePerUnit=true: Price is multiplied by interval ratio
- Example: Monthly billing, weekly delivery = price × 4
- When isPricePerUnit=false: Price is used as total billing amount

Update Process:
1. Validates line item exists in the subscription
2. Calculates interval multiplier for prepaid logic
3. Updates in order: selling plan → price → quantity → variant
4. Each update uses separate Shopify GraphQL mutation
5. Failures are logged but don't block other updates

Selling Plan Updates:
- Can update by ID or name (name takes precedence)
- Only updates if different from current plan
- Useful for changing delivery frequency options

Price Updates:
- Preserves existing discount cycles (up to 2 cycles)
- Recalculates cycle discounts based on new base price
- Triggers shipping price recalculation
- Sends price update email to customer

Quantity Updates:
- Validates against min/max quantity rules
- Updates Build-a-Box totals if applicable
- May trigger discount recalculations

Variant Updates:
- Changes the product itself (different SKU)
- Validates new variant exists and is available
- May affect pricing and discounts

Important Notes:
- All parameters except contractId and lineId are optional
- Provide only the values you want to change
- Price is always in shop's base currency
- Changes apply to future orders only

Authentication: Requires valid X-API-Key header

Endpoint: PUT /api/external/v2/subscription-contracts-update-line-item
Version: 0.0.1

## Query parameters:

  - `contractId` (integer, required)
    Subscription contract ID
    Example: 123456789

  - `quantity` (integer)
    New quantity for the line item. Leave unchanged if not updating quantity.
    Example: 3

  - `variantId` (string)
    New product variant ID in Shopify GID format (e.g., gid://shopify/ProductVariant/42549172011164). This updates the associated product. Leave this parameter blank if you are not switching products.
    Example: "gid://shopify/ProductVariant/42549172011164"

  - `lineId` (string, required)
    Line item ID to update. Must be the full GraphQL ID including gid:// prefix
    Example: "gid://shopify/SubscriptionLine/111111"

  - `price` (number)
    New price for the line item in shop currency. Behavior depends on isPricePerUnit flag.
    Example: 29.99

  - `isPricePerUnit` (boolean)
    Determines how price is interpreted for prepaid subscriptions:
- true: Price is per unit (per delivery), will be multiplied by interval ratio
- false: Price is total billing amount (for all deliveries in billing period)

Example: Monthly billing, weekly delivery, price=$10
- isPricePerUnit=true: Customer pays $40/month ($10 × 4 weeks)
- isPricePerUnit=false: Customer pays $10/month total

  - `sellingPlanName` (string)
    Name of the selling plan to apply. Takes precedence over current selling plan. Used to change delivery frequencies.
    Example: "Deliver every 2 weeks"

  - `api_key` (string)
    API Key (Deprecated - Use X-API-Key header instead)

## Header parameters:

  - `X-API-Key` (string, required)
    API Key for authentication

## Response 200 fields (application/json):

  - `get__typename` (string)

  - `id` (string)

  - `createdAt` (object)

  - `updatedAt` (object)

  - `nextBillingDate` (object)

  - `status` (string)
    Enum: "ACTIVE", "PAUSED", "CANCELLED", "EXPIRED", "FAILED", "$UNKNOWN"

  - `deliveryPrice` (object)

  - `deliveryPrice.amount` (object)

  - `deliveryPrice.currencyCode` (string)
    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"

  - `lastPaymentStatus` (string)
    Enum: "SUCCEEDED", "FAILED", "$UNKNOWN"

  - `billingPolicy` (object)

  - `billingPolicy.interval` (string)
    Enum: "DAY", "WEEK", "MONTH", "YEAR", "$UNKNOWN"

  - `billingPolicy.intervalCount` (integer)

  - `billingPolicy.anchors` (array)

  - `billingPolicy.anchors.cutoffDay` (integer)

  - `billingPolicy.anchors.day` (integer)

  - `billingPolicy.anchors.month` (integer)

  - `billingPolicy.anchors.type` (string)
    Enum: "WEEKDAY", "MONTHDAY", "YEARDAY", "$UNKNOWN"

  - `billingPolicy.maxCycles` (integer)

  - `billingPolicy.minCycles` (integer)

  - `deliveryPolicy` (object)

  - `lines` (object)

  - `lines.nodes` (array)

  - `lines.nodes.sellingPlanId` (string)

  - `lines.nodes.sellingPlanName` (string)

  - `lines.nodes.productId` (string)

  - `lines.nodes.sku` (string)

  - `lines.nodes.title` (string)

  - `lines.nodes.variantId` (string)

  - `lines.nodes.quantity` (integer)

  - `lines.nodes.customAttributes` (array)

  - `lines.nodes.customAttributes.key` (string)

  - `lines.nodes.customAttributes.value` (string)

  - `lines.nodes.lineDiscountedPrice` (object)

  - `lines.nodes.variantImage` (object)

  - `lines.nodes.variantImage.transformedSrc` (object)

  - `lines.nodes.variantTitle` (string)

  - `lines.nodes.currentPrice` (object)

  - `lines.nodes.discountAllocations` (array)

  - `lines.nodes.discountAllocations.discount` (object)

  - `lines.nodes.pricingPolicy` (object)

  - `lines.nodes.pricingPolicy.basePrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts` (array)

  - `lines.nodes.pricingPolicy.cycleDiscounts.afterCycle` (integer)

  - `lines.nodes.pricingPolicy.cycleDiscounts.computedPrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentType` (string)
    Enum: "PERCENTAGE", "FIXED_AMOUNT", "PRICE", "$UNKNOWN"

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentValue` (object)

  - `lines.nodes.taxable` (boolean)

  - `lines.pageInfo` (object)

  - `lines.pageInfo.hasPreviousPage` (boolean)

  - `lines.pageInfo.hasNextPage` (boolean)

  - `lines.pageInfo.startCursor` (string)

  - `lines.pageInfo.endCursor` (string)

  - `customerPaymentMethod` (object)

  - `customerPaymentMethod.instrument` (object)

  - `customerPaymentMethod.revokedAt` (object)

  - `customerPaymentMethod.revokedReason` (string)
    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"

  - `deliveryMethod` (object)

  - `originOrder` (object)

  - `originOrder.name` (string)

  - `originOrder.fulfillmentOrders` (object)

  - `customer` (object)

  - `customer.displayName` (string)

  - `customer.firstName` (string)

  - `customer.lastName` (string)

  - `customer.email` (string)

  - `customer.phone` (string)

  - `discounts` (object)

  - `note` (string)

  - `billingAttempts` (object)

## Response 207 fields (application/json):

  - `get__typename` (string)

  - `id` (string)

  - `createdAt` (object)

  - `updatedAt` (object)

  - `nextBillingDate` (object)

  - `status` (string)
    Enum: "ACTIVE", "PAUSED", "CANCELLED", "EXPIRED", "FAILED", "$UNKNOWN"

  - `deliveryPrice` (object)

  - `deliveryPrice.amount` (object)

  - `deliveryPrice.currencyCode` (string)
    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"

  - `lastPaymentStatus` (string)
    Enum: "SUCCEEDED", "FAILED", "$UNKNOWN"

  - `billingPolicy` (object)

  - `billingPolicy.interval` (string)
    Enum: "DAY", "WEEK", "MONTH", "YEAR", "$UNKNOWN"

  - `billingPolicy.intervalCount` (integer)

  - `billingPolicy.anchors` (array)

  - `billingPolicy.anchors.cutoffDay` (integer)

  - `billingPolicy.anchors.day` (integer)

  - `billingPolicy.anchors.month` (integer)

  - `billingPolicy.anchors.type` (string)
    Enum: "WEEKDAY", "MONTHDAY", "YEARDAY", "$UNKNOWN"

  - `billingPolicy.maxCycles` (integer)

  - `billingPolicy.minCycles` (integer)

  - `deliveryPolicy` (object)

  - `lines` (object)

  - `lines.nodes` (array)

  - `lines.nodes.sellingPlanId` (string)

  - `lines.nodes.sellingPlanName` (string)

  - `lines.nodes.productId` (string)

  - `lines.nodes.sku` (string)

  - `lines.nodes.title` (string)

  - `lines.nodes.variantId` (string)

  - `lines.nodes.quantity` (integer)

  - `lines.nodes.customAttributes` (array)

  - `lines.nodes.customAttributes.key` (string)

  - `lines.nodes.customAttributes.value` (string)

  - `lines.nodes.lineDiscountedPrice` (object)

  - `lines.nodes.variantImage` (object)

  - `lines.nodes.variantImage.transformedSrc` (object)

  - `lines.nodes.variantTitle` (string)

  - `lines.nodes.currentPrice` (object)

  - `lines.nodes.discountAllocations` (array)

  - `lines.nodes.discountAllocations.discount` (object)

  - `lines.nodes.pricingPolicy` (object)

  - `lines.nodes.pricingPolicy.basePrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts` (array)

  - `lines.nodes.pricingPolicy.cycleDiscounts.afterCycle` (integer)

  - `lines.nodes.pricingPolicy.cycleDiscounts.computedPrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentType` (string)
    Enum: "PERCENTAGE", "FIXED_AMOUNT", "PRICE", "$UNKNOWN"

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentValue` (object)

  - `lines.nodes.taxable` (boolean)

  - `lines.pageInfo` (object)

  - `lines.pageInfo.hasPreviousPage` (boolean)

  - `lines.pageInfo.hasNextPage` (boolean)

  - `lines.pageInfo.startCursor` (string)

  - `lines.pageInfo.endCursor` (string)

  - `customerPaymentMethod` (object)

  - `customerPaymentMethod.instrument` (object)

  - `customerPaymentMethod.revokedAt` (object)

  - `customerPaymentMethod.revokedReason` (string)
    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"

  - `deliveryMethod` (object)

  - `originOrder` (object)

  - `originOrder.name` (string)

  - `originOrder.fulfillmentOrders` (object)

  - `customer` (object)

  - `customer.displayName` (string)

  - `customer.firstName` (string)

  - `customer.lastName` (string)

  - `customer.email` (string)

  - `customer.phone` (string)

  - `discounts` (object)

  - `note` (string)

  - `billingAttempts` (object)

## Response 404 fields (*/*):

  - `get__typename` (string)

  - `id` (string)

  - `createdAt` (object)

  - `updatedAt` (object)

  - `nextBillingDate` (object)

  - `status` (string)
    Enum: "ACTIVE", "PAUSED", "CANCELLED", "EXPIRED", "FAILED", "$UNKNOWN"

  - `deliveryPrice` (object)

  - `deliveryPrice.amount` (object)

  - `deliveryPrice.currencyCode` (string)
    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"

  - `lastPaymentStatus` (string)
    Enum: "SUCCEEDED", "FAILED", "$UNKNOWN"

  - `billingPolicy` (object)

  - `billingPolicy.interval` (string)
    Enum: "DAY", "WEEK", "MONTH", "YEAR", "$UNKNOWN"

  - `billingPolicy.intervalCount` (integer)

  - `billingPolicy.anchors` (array)

  - `billingPolicy.anchors.cutoffDay` (integer)

  - `billingPolicy.anchors.day` (integer)

  - `billingPolicy.anchors.month` (integer)

  - `billingPolicy.anchors.type` (string)
    Enum: "WEEKDAY", "MONTHDAY", "YEARDAY", "$UNKNOWN"

  - `billingPolicy.maxCycles` (integer)

  - `billingPolicy.minCycles` (integer)

  - `deliveryPolicy` (object)

  - `lines` (object)

  - `lines.nodes` (array)

  - `lines.nodes.sellingPlanId` (string)

  - `lines.nodes.sellingPlanName` (string)

  - `lines.nodes.productId` (string)

  - `lines.nodes.sku` (string)

  - `lines.nodes.title` (string)

  - `lines.nodes.variantId` (string)

  - `lines.nodes.quantity` (integer)

  - `lines.nodes.customAttributes` (array)

  - `lines.nodes.customAttributes.key` (string)

  - `lines.nodes.customAttributes.value` (string)

  - `lines.nodes.lineDiscountedPrice` (object)

  - `lines.nodes.variantImage` (object)

  - `lines.nodes.variantImage.transformedSrc` (object)

  - `lines.nodes.variantTitle` (string)

  - `lines.nodes.currentPrice` (object)

  - `lines.nodes.discountAllocations` (array)

  - `lines.nodes.discountAllocations.discount` (object)

  - `lines.nodes.pricingPolicy` (object)

  - `lines.nodes.pricingPolicy.basePrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts` (array)

  - `lines.nodes.pricingPolicy.cycleDiscounts.afterCycle` (integer)

  - `lines.nodes.pricingPolicy.cycleDiscounts.computedPrice` (object)

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentType` (string)
    Enum: "PERCENTAGE", "FIXED_AMOUNT", "PRICE", "$UNKNOWN"

  - `lines.nodes.pricingPolicy.cycleDiscounts.adjustmentValue` (object)

  - `lines.nodes.taxable` (boolean)

  - `lines.pageInfo` (object)

  - `lines.pageInfo.hasPreviousPage` (boolean)

  - `lines.pageInfo.hasNextPage` (boolean)

  - `lines.pageInfo.startCursor` (string)

  - `lines.pageInfo.endCursor` (string)

  - `customerPaymentMethod` (object)

  - `customerPaymentMethod.instrument` (object)

  - `customerPaymentMethod.revokedAt` (object)

  - `customerPaymentMethod.revokedReason` (string)
    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"

  - `deliveryMethod` (object)

  - `originOrder` (object)

  - `originOrder.name` (string)

  - `originOrder.fulfillmentOrders` (object)

  - `customer` (object)

  - `customer.displayName` (string)

  - `customer.firstName` (string)

  - `customer.lastName` (string)

  - `customer.email` (string)

  - `customer.phone` (string)

  - `discounts` (object)

  - `note` (string)

  - `billingAttempts` (object)


## Response 400 fields

## Response 401 fields

## Response 403 fields