> For the complete documentation index, see [llms.txt](https://docs.ecwid.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ecwid.com/changelog/september-2025/september-19/store-id-is-now-required-for-external-apps-authentication.md).

# Store ID is now required for external apps' authentication

{% hint style="danger" %}
**Breaking changes!**\
When released, the changes listed below will break some apps' logic. Please update your apps to ensure they are ready for the change.
{% endhint %}

#### What's new

A small addition to the authentication flow for external apps. When a user installs the app, you now receive not only the **temporary code**, but also the **store ID** on your server. And to obtain the access token for that store, you need to pass both the **code** and **store ID** in the following <mark style="color:blue;">`POST`</mark> request.

{% content-ref url="/spaces/uOzT5egoVTAjMJwRuMQT/pages/AFVM0V8oFIdw8c7C5bft" %}
[Native and external apps](/launch-apps/native-and-external-apps.md)
{% endcontent-ref %}

#### Changes in API

Before the change, incoming token requests looked like:

```
https://www.example.com/myapp?code=abcd123456
```

where:

* `https://www.example.com/myapp`  is the **redirectUrl**
* `abcd123456`  is the **code**

Now incoming requests have an additional parameter:

```
https://www.example.com/myapp?code=abcd123456&store_id=1003 
```

where:

* `1003` is the store ID from which the installation was triggered

And here is how your following request for the access token should look:

```http
POST /api/oauth/token/{store_id} HTTP/1.1
Host: my.ecwid.com
Content-Type: application/x-www-form-urlencoded

client_id={client_id}&client_secret={client_secret}&code={code}&redirect_uri={redirect_uri}&grant_type=authorization_code
```

The only change here is the new **{store\_id} param** passed in the request path.

#### Timeline

For now, we support both the old and the new flows for external apps' authentication. We recommend updating your applications now.

The old flow will be disabled **in \~5-6 months**. However, we'll monitor non-updated apps and notify developers before shutdown.

#### How to update the app

1. Check if your app is an external app. External applications handle the authentication process (when users install the app) on their side and have a **redirectUrl** specified in the app dashboard.
2. Make sure your **redirectUrl** parses both `code` and `store_id` query params from incoming requests.
3. Add `/{store_id}` path param to the follow-up call.\
   So it looks like <mark style="color:blue;">`POST`</mark> `/api/oauth/token/{store_id}` \
   instead of <mark style="color:blue;">`POST`</mark> `/api/oauth/token`


---

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