Membership Contracts

Add a product to an existing membership contract

Adds a new product/variant line item to an existing active membership contract. This allows customers or merchants to add additional products to their recurring membership orders.

Key Features:

Add any product variant to an existing membership
Specify custom quantity and price per line item
Product will be included in all future billing cycles
Price is per-item, total line price = price × quantity

Important Notes:

Immediate Effect: Product is added immediately and will appear in the next billing cycle
Price Override: The price parameter allows setting a custom price (e.g., member discount)
Activity Logging: Addition is logged for audit trail
Validation: System validates that the variant exists and is available

Common Use Cases:

Customer wants to add more products to their monthly membership box
Merchant adds a complimentary product to a membership
Upgrading membership with additional items
Adding seasonal or limited-time products to existing memberships

Price Considerations:

Price is specified in shop’s currency
Can be set to member-only pricing (different from regular product price)
Zero price is allowed for free add-ons

Variant ID Format:

Accepts both numeric ID (e.g., ‘987654321’) and Shopify GID format
System will convert to proper Shopify GraphQL format internally

Authentication: Requires authenticated shop user or customer portal token

PUT

memberships

api

subscription-contracts-add-line-item

Add a product to an existing membership contract

curl --request PUT \
  --url https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item

const options = {method: 'PUT'};

fetch('https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

const url = 'https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item';
const options = {method: 'PUT'};

fetch(url, options)
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item"

	req, _ := http.NewRequest("PUT", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Put.new(url)

response = http.request(request)
puts response.read_body

{
  "billingAttempts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "completedAt": {},
        "createdAt": {},
        "get__typename": "<string>",
        "id": "<string>",
        "idempotencyKey": "<string>",
        "ready": true
      }
    ]
  },
  "billingPolicy": {
    "anchors": [
      {
        "cutoffDay": 123,
        "day": 123,
        "get__typename": "<string>",
        "month": 123,
        "type": "WEEKDAY"
      }
    ],
    "get__typename": "<string>",
    "interval": "DAY",
    "intervalCount": 123,
    "maxCycles": 123,
    "minCycles": 123
  },
  "createdAt": {},
  "customAttributes": [
    {
      "get__typename": "<string>",
      "key": "<string>",
      "value": "<string>"
    }
  ],
  "customer": {
    "displayName": "<string>",
    "email": "<string>",
    "firstName": "<string>",
    "get__typename": "<string>",
    "id": "<string>",
    "lastName": "<string>",
    "phone": "<string>"
  },
  "customerPaymentMethod": {
    "get__typename": "<string>",
    "id": "<string>",
    "instrument": {
      "get__typename": "<string>"
    },
    "revokedAt": {},
    "revokedReason": "AUTHORIZE_NET_GATEWAY_NOT_ENABLED"
  },
  "deliveryMethod": {
    "get__typename": "<string>"
  },
  "deliveryPolicy": {
    "anchors": [
      {
        "cutoffDay": 123,
        "day": 123,
        "get__typename": "<string>",
        "month": 123,
        "type": "WEEKDAY"
      }
    ],
    "get__typename": "<string>",
    "interval": "DAY",
    "intervalCount": 123
  },
  "deliveryPrice": {
    "amount": {},
    "currencyCode": "USD",
    "get__typename": "<string>"
  },
  "discounts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "get__typename": "<string>",
        "id": "<string>",
        "recurringCycleLimit": 123,
        "rejectionReason": "NOT_FOUND",
        "targetType": "LINE_ITEM",
        "title": "<string>",
        "type": "MANUAL",
        "usageCount": 123,
        "value": {
          "get__typename": "<string>"
        }
      }
    ],
    "pageInfo": {
      "endCursor": "<string>",
      "get__typename": "<string>",
      "hasNextPage": true,
      "hasPreviousPage": true,
      "startCursor": "<string>"
    }
  },
  "get__typename": "<string>",
  "id": "<string>",
  "lastPaymentStatus": "SUCCEEDED",
  "lines": {
    "get__typename": "<string>",
    "nodes": [
      {
        "currentPrice": {
          "amount": {},
          "currencyCode": "USD",
          "get__typename": "<string>"
        },
        "customAttributes": [
          {
            "get__typename": "<string>",
            "key": "<string>",
            "value": "<string>"
          }
        ],
        "discountAllocations": [
          {
            "amount": {
              "amount": {},
              "currencyCode": "USD",
              "get__typename": "<string>"
            },
            "discount": {
              "get__typename": "<string>"
            },
            "get__typename": "<string>"
          }
        ],
        "get__typename": "<string>",
        "id": "<string>",
        "lineDiscountedPrice": {
          "amount": {},
          "currencyCode": "USD",
          "get__typename": "<string>"
        },
        "pricingPolicy": {
          "basePrice": {
            "amount": {},
            "currencyCode": "USD",
            "get__typename": "<string>"
          },
          "cycleDiscounts": [
            {
              "adjustmentType": "PERCENTAGE",
              "adjustmentValue": {
                "get__typename": "<string>"
              },
              "afterCycle": 123,
              "computedPrice": {
                "amount": {},
                "currencyCode": "USD",
                "get__typename": "<string>"
              },
              "get__typename": "<string>"
            }
          ],
          "get__typename": "<string>"
        },
        "productId": "<string>",
        "quantity": 123,
        "sellingPlanId": "<string>",
        "sellingPlanName": "<string>",
        "sku": "<string>",
        "taxable": true,
        "title": "<string>",
        "variantId": "<string>",
        "variantImage": {
          "get__typename": "<string>",
          "url": {}
        },
        "variantTitle": "<string>"
      }
    ],
    "pageInfo": {
      "endCursor": "<string>",
      "get__typename": "<string>",
      "hasNextPage": true,
      "hasPreviousPage": true,
      "startCursor": "<string>"
    }
  },
  "nextBillingDate": {},
  "note": "<string>",
  "originOrder": {
    "fulfillmentOrders": {
      "get__typename": "<string>",
      "nodes": [
        {
          "fulfillAt": {},
          "get__typename": "<string>",
          "id": "<string>",
          "status": "OPEN"
        }
      ],
      "pageInfo": {
        "endCursor": "<string>",
        "get__typename": "<string>",
        "hasNextPage": true,
        "hasPreviousPage": true,
        "startCursor": "<string>"
      }
    },
    "get__typename": "<string>",
    "id": "<string>",
    "name": "<string>"
  },
  "status": "ACTIVE",
  "updatedAt": {}
}

Query Parameters

contractId

integer<int64>

required

Membership contract ID to add product to

shop

string

required

Shop domain (will be auto-populated from authentication)

quantity

integer<int32>

required

Quantity of the product to add

variantId

string

required

Shopify variant ID of the product to add (numeric or GID format)

price

number<double>

required

Price per unit in shop currency (allows custom/member pricing)

Response

Product successfully added to membership contract

billingAttempts

object

Show child attributes

billingPolicy

object

Show child attributes

createdAt

object

customAttributes

object[]

Show child attributes

customer

object

Show child attributes

customerPaymentMethod

object

Show child attributes

deliveryMethod

object

Show child attributes

deliveryPolicy

object

Show child attributes

deliveryPrice

object

Show child attributes

discounts

object

Show child attributes

get__typename

string

lastPaymentStatus

enum<string>

Available options:

SUCCEEDED,

FAILED,

$UNKNOWN

lines

object

Show child attributes

nextBillingDate

object

note

string

originOrder

object

Show child attributes

status

enum<string>

Available options:

ACTIVE,

PAUSED,

CANCELLED,

EXPIRED,

FAILED,

$UNKNOWN

updatedAt

object

Add a product to an existing membership contract

curl --request PUT \
  --url https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item

const options = {method: 'PUT'};

fetch('https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

const url = 'https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item';
const options = {method: 'PUT'};

fetch(url, options)
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item"

	req, _ := http.NewRequest("PUT", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://www.myshop.com/apps/memberships/cp/api/subscription-contracts-add-line-item")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Put.new(url)

response = http.request(request)
puts response.read_body

{
  "billingAttempts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "completedAt": {},
        "createdAt": {},
        "get__typename": "<string>",
        "id": "<string>",
        "idempotencyKey": "<string>",
        "ready": true
      }
    ]
  },
  "billingPolicy": {
    "anchors": [
      {
        "cutoffDay": 123,
        "day": 123,
        "get__typename": "<string>",
        "month": 123,
        "type": "WEEKDAY"
      }
    ],
    "get__typename": "<string>",
    "interval": "DAY",
    "intervalCount": 123,
    "maxCycles": 123,
    "minCycles": 123
  },
  "createdAt": {},
  "customAttributes": [
    {
      "get__typename": "<string>",
      "key": "<string>",
      "value": "<string>"
    }
  ],
  "customer": {
    "displayName": "<string>",
    "email": "<string>",
    "firstName": "<string>",
    "get__typename": "<string>",
    "id": "<string>",
    "lastName": "<string>",
    "phone": "<string>"
  },
  "customerPaymentMethod": {
    "get__typename": "<string>",
    "id": "<string>",
    "instrument": {
      "get__typename": "<string>"
    },
    "revokedAt": {},
    "revokedReason": "AUTHORIZE_NET_GATEWAY_NOT_ENABLED"
  },
  "deliveryMethod": {
    "get__typename": "<string>"
  },
  "deliveryPolicy": {
    "anchors": [
      {
        "cutoffDay": 123,
        "day": 123,
        "get__typename": "<string>",
        "month": 123,
        "type": "WEEKDAY"
      }
    ],
    "get__typename": "<string>",
    "interval": "DAY",
    "intervalCount": 123
  },
  "deliveryPrice": {
    "amount": {},
    "currencyCode": "USD",
    "get__typename": "<string>"
  },
  "discounts": {
    "get__typename": "<string>",
    "nodes": [
      {
        "get__typename": "<string>",
        "id": "<string>",
        "recurringCycleLimit": 123,
        "rejectionReason": "NOT_FOUND",
        "targetType": "LINE_ITEM",
        "title": "<string>",
        "type": "MANUAL",
        "usageCount": 123,
        "value": {
          "get__typename": "<string>"
        }
      }
    ],
    "pageInfo": {
      "endCursor": "<string>",
      "get__typename": "<string>",
      "hasNextPage": true,
      "hasPreviousPage": true,
      "startCursor": "<string>"
    }
  },
  "get__typename": "<string>",
  "id": "<string>",
  "lastPaymentStatus": "SUCCEEDED",
  "lines": {
    "get__typename": "<string>",
    "nodes": [
      {
        "currentPrice": {
          "amount": {},
          "currencyCode": "USD",
          "get__typename": "<string>"
        },
        "customAttributes": [
          {
            "get__typename": "<string>",
            "key": "<string>",
            "value": "<string>"
          }
        ],
        "discountAllocations": [
          {
            "amount": {
              "amount": {},
              "currencyCode": "USD",
              "get__typename": "<string>"
            },
            "discount": {
              "get__typename": "<string>"
            },
            "get__typename": "<string>"
          }
        ],
        "get__typename": "<string>",
        "id": "<string>",
        "lineDiscountedPrice": {
          "amount": {},
          "currencyCode": "USD",
          "get__typename": "<string>"
        },
        "pricingPolicy": {
          "basePrice": {
            "amount": {},
            "currencyCode": "USD",
            "get__typename": "<string>"
          },
          "cycleDiscounts": [
            {
              "adjustmentType": "PERCENTAGE",
              "adjustmentValue": {
                "get__typename": "<string>"
              },
              "afterCycle": 123,
              "computedPrice": {
                "amount": {},
                "currencyCode": "USD",
                "get__typename": "<string>"
              },
              "get__typename": "<string>"
            }
          ],
          "get__typename": "<string>"
        },
        "productId": "<string>",
        "quantity": 123,
        "sellingPlanId": "<string>",
        "sellingPlanName": "<string>",
        "sku": "<string>",
        "taxable": true,
        "title": "<string>",
        "variantId": "<string>",
        "variantImage": {
          "get__typename": "<string>",
          "url": {}
        },
        "variantTitle": "<string>"
      }
    ],
    "pageInfo": {
      "endCursor": "<string>",
      "get__typename": "<string>",
      "hasNextPage": true,
      "hasPreviousPage": true,
      "startCursor": "<string>"
    }
  },
  "nextBillingDate": {},
  "note": "<string>",
  "originOrder": {
    "fulfillmentOrders": {
      "get__typename": "<string>",
      "nodes": [
        {
          "fulfillAt": {},
          "get__typename": "<string>",
          "id": "<string>",
          "status": "OPEN"
        }
      ],
      "pageInfo": {
        "endCursor": "<string>",
        "get__typename": "<string>",
        "hasNextPage": true,
        "hasPreviousPage": true,
        "startCursor": "<string>"
      }
    },
    "get__typename": "<string>",
    "id": "<string>",
    "name": "<string>"
  },
  "status": "ACTIVE",
  "updatedAt": {}
}

Get Started

Guides

Partner Integration

Webhooks

Admin API

Customer Portal API

Add a product to an existing membership contract

Query Parameters

Response