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.

Full behavior, validation rules, and side effects

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

PUT /api/external/v2/subscription-contract-update-variant

Update product variant in subscription contract

cURL

curl --request PUT \
  --url https://membership-admin.appstle.com/api/external/v2/subscription-contract-update-variant

200

Example

{
  "get__typename": "<string>",
  "id": "<string>",
  "createdAt": {},
  "updatedAt": {},
  "nextBillingDate": {},
  "deliveryPrice": {
    "get__typename": "<string>",
    "amount": {}
  },
  "billingPolicy": {
    "get__typename": "<string>",
    "intervalCount": 123,
    "anchors": [
      {
        "get__typename": "<string>",
        "cutoffDay": 123,
        "day": 123,
        "month": 123
      }
    ],
    "maxCycles": 123,
    "minCycles": 123
  },
  "deliveryPolicy": {
    "get__typename": "<string>",
    "intervalCount": 123,
    "anchors": [
      {
        "get__typename": "<string>",
        "cutoffDay": 123,
        "day": 123,
        "month": 123
      }
    ]
  },
  "lines": {
    "get__typename": "<string>",
    "nodes": [
      {
        "get__typename": "<string>"
      }
    ],
    "pageInfo": {
      "get__typename": "<string>",
      "hasPreviousPage": true,
      "hasNextPage": true,
      "startCursor": "<string>",
      "endCursor": "<string>"
    }
  },
  "customerPaymentMethod": {
    "get__typename": "<string>",
    "id": "<string>",
    "instrument": {
      "get__typename": "<string>"
    },
    "revokedAt": {}
  },
  "deliveryMethod": {
    "get__typename": "<string>",
    "id": "<string>",
    "serviceCode": "<string>",
    "minDeliveryDateTime": {},
    "maxDeliveryDateTime": {},
    "additionalInformation": {
      "get__typename": "<string>",
      "instructions": "<string>"
    },
    "brandedPromise": {
      "get__typename": "<string>",
      "handle": "<string>",
      "name": "<string>"
    }
  },
  "originOrder": {
    "get__typename": "<string>",
    "id": "<string>",
    "name": "<string>",
    "fulfillmentOrders": {
      "get__typename": "<string>",
      "nodes": [
        {
          "get__typename": "<string>"
        }
      ],
      "pageInfo": {
        "get__typename": "<string>",
        "hasPreviousPage": true,
        "hasNextPage": true,
        "startCursor": "<string>",
        "endCursor": "<string>"
      }
    }
  },
  "customer": {
    "get__typename": "<string>",
    "id": "<string>",
    "email": "<string>",
    "displayName": "<string>",
    "firstName": "<string>",
    "lastName": "<string>",
    "phone": "<string>"
  },
  "discounts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "get__typename": "<string>",
        "createdAt": {},
        "deliveredAt": {},
        "estimatedDeliveryAt": {},
        "id": "<string>",
        "inTransitAt": {},
        "name": "<string>",
        "requiresShipping": true,
        "service": {
          "get__typename": "<string>",
          "handle": "<string>",
          "serviceName": "<string>"
        },
        "trackingInfo": [
          {
            "get__typename": "<string>",
            "url": {},
            "number": "<string>",
            "company": "<string>"
          }
        ]
      }
    ],
    "pageInfo": {
      "get__typename": "<string>",
      "hasPreviousPage": true,
      "hasNextPage": true,
      "startCursor": "<string>",
      "endCursor": "<string>"
    }
  },
  "note": "<string>",
  "customAttributes": [
    {
      "get__typename": "<string>",
      "key": "<string>",
      "value": "<string>"
    }
  ],
  "billingAttempts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "get__typename": "<string>",
        "completedAt": {},
        "createdAt": {},
        "id": "<string>",
        "idempotencyKey": "<string>",
        "ready": true
      }
    ]
  }
}

Headers

X-API-Key · string

Query Parameters

contractId · integer<int64> · required

Subscription contract ID

api_key · string

API Key (Deprecated - Use Header X-API-Key instead)

oldLineId · string

Line item ID to replace (provide either oldLineId or oldVariantId)

oldVariantId · string

Old variant ID to replace (provide either oldLineId or oldVariantId)

newVariantId · string · required

New variant ID to use as replacement

skipBilling · boolean · default: false

Skip billing on plan change (no charge or refund)

Response

200

application/json

Variant successfully updated in subscription contract

get__typename · string

id · string

createdAt · object

updatedAt · object

nextBillingDate · object

status · enum<string>

Available options: ACTIVE, PAUSED, CANCELLED, EXPIRED, FAILED, $UNKNOWN

deliveryPrice · object

Show child attributes

lastPaymentStatus · enum<string>

Available options: SUCCEEDED, FAILED, $UNKNOWN

billingPolicy · object

Show child attributes

deliveryPolicy · object

Show child attributes

lines · object

Show child attributes

customerPaymentMethod · object

Show child attributes

deliveryMethod · object

Show child attributes

originOrder · object

Show child attributes

customer · object

Show child attributes

discounts · object

Show child attributes

note · string

customAttributes · object[]

Show child attributes

billingAttempts · object

Show child attributes