---
title: "Add line once (for next order)"
method: POST
path: "/2026-04/subscription/{subscriptionId}/line/once"
---

# Add line once (for next order)

`POST /2026-04/subscription/{subscriptionId}/line/once`

## Request

- Base URL: `https://api.loopsubscriptions.com/storefront`
- URL: `https://api.loopsubscriptions.com/storefront/2026-04/subscription/{subscriptionId}/line/once`
- Auth: API key in header `Authorization`

This endpoint allows you to add a one-time product to the customer's next subscription order without affecting future recurring orders.

## Path parameters

- `subscriptionId` integer, required

## Request body

- object
  - `variantShopifyId` integer, required: The unique identifier of the variant in Shopify.
  - `quantity` integer: The quantity of variant to be added.
  - `isUpsell` boolean: This key allows you to track upsell analytics by indicating whether an item is an upsell or not.
  - `upsellProfileId` integer: This key allows you to track the exact upsell profile analytics.
  - `customAttributes` object
    - `key` string: The name or identifier of the attribute.
    - `value` string: The corresponding data for that key.

## Response `200`

Line added for next order successfully

- object
  - `success` boolean
  - `message` string
  - `data` object
    - `id` integer
    - `name` string
    - `shopifyId` string
    - `quantity` integer
    - `price` string
  - `code` string
  - `pageInfo` unknown

## Changes

- **2026-11-03** `1ff6a5700816`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/loopwork/apis/storefront-api/changes/2026-04/subscription/:subscriptionId/line/once/post.md)

---

[API](https://skmtc.dev/loopwork/apis/storefront-api.md) - [All operations](https://skmtc.dev/loopwork/apis/storefront-api/llms.txt) - [OpenAPI document](https://skmtc.dev/loopwork/apis/storefront-api/revisions/1ff6a5700816?raw)