---
title: "Link add-ons to a subscription"
method: POST
path: "/subscriptions/{subscriptionId}/add-ons"
tags: ["Subscriptions"]
---

# Link add-ons to a subscription

`POST /subscriptions/{subscriptionId}/add-ons`

Link one or more add-ons to a subscription by subscription id

## Path parameters

- `subscriptionId` integer, required

## Headers

- `api-token` string, required

## Request body

- SubscriptionAddOnCreationReq
  - `addOns` SubscriptionAddOnCreateInner[] — The add-ons linked to the payment plan to apply to the subscription
    - `addOnId` integer, required — The id of the linked plan add-on to apply to the subscription
    - `quantity` integer — The number of duplicates of the indicated add-on to apply to the target subscription. If provided the add-on must support quantity editing to apply the specified quantity.

## Response `201`

Successful linking of add-ons to the subscription. The response body contains the data representation of  all newly linked add-ons.

- SubscriptionAddOnCreationRes
  - `data` BaseSubscriptionAddOn[]
    - `addOnId` integer
    - `name` string
    - `description` string
    - `amount` number, float
    - `firstProcessedNumber` integer
    - `lastProcessedNumber` integer
    - `isActive` string
    - `frequency` string
    - `quantity` integer

## Other responses

- `400` — You are initiating a request with invalid parameter and/or body values.
- `401` — You are not authorized to access this resource. Please ensure that you are authenticated, and that you are using the `api-token` header
- `403` — You do not have permission to access this resource. Please ensure you are both authenticated and that you have the required roles/permissions active.
- `500` — Helcim internal server error encountered.

---

[API](https://skmtc.net/helcim/apis/the-helcim-api.md) · [All operations](https://skmtc.net/helcim/apis/the-helcim-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/helcim/the-helcim-api/versions/345052ca6578/schema)