Add product to recurring subscription

Adds a new product variant to a subscription contract’s recurring line items. The product will be included in all future recurring orders.

Full behavior, validation rules, and side effects

Product Addition Process:

• Variant Validation: Verifies product variant exists and is available
• Add to Contract: Adds line item to subscription’s recurring products
• Quantity Setting: Sets initial quantity for the product
• Price Calculation: Calculates pricing including any applicable discounts
• Shipping Update: May recalculate shipping if weight/dimensions change
• Activity Logging: Records product addition event

Key Features:

• Recurring Addition: Product added to every future order
• Quantity Control: Specify exact quantity to add
• Discount Inheritance: New item inherits subscription-level discounts
• Immediate Effect: Applies to next billing cycle
• Freeze Protection: Validates subscription isn’t frozen before minimum cycles

Variant ID Format:

• Accepts Shopify variant ID as string
• Can be numeric ID or GraphQL format
• Example: “12345678” or “gid://shopify/ProductVariant/12345678”

Use Cases:

• Customer upgrades subscription to include more products
• Cross-sell additional products to existing subscribers
• Allow customers to customize subscriptions in portal
• Add seasonal products to subscriptions
• Build-a-box subscription customization
• Upsell workflows during customer interactions

Important Notes:

• Product must be available for purchase
• Subscription must not be frozen (before min cycles)
• Price updates automatically with subscription billing
• Quantity must be positive integer

Returns: Updated subscription contract object with new line item

Authentication: Requires API key authentication via X-API-Key header or api_key parameter

PUT /api/external/v2/subscription-contracts-add-line-item

Add product to recurring subscription

cURL

curl --request PUT \
  --url https://membership-admin.appstle.com/api/external/v2/subscription-contracts-add-line-item

200

{
  "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 to add product to

api_key · string

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

quantity · integer<int32> · required

Quantity of the product to add

variantId · string · required

Shopify product variant ID

Response

200

application/json

Product successfully added to subscription

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