> For the complete documentation index, see [llms.txt](https://docs.parallels.com/landing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.parallels.com/landing/ras-client-integration-guide/v21/ras-web-client-api/authentication-handoff-api.md).

# Authentication Handoff API

The Authentication Handoff API lets your web portal sign a user in to the RAS User Portal and optionally launch a published resource immediately with a single HTTP POST. It replaces the legacy appinfo payload mechanism and is the supported method for all new integrations.

Unlike the legacy API, no launch data is passed through a URL and no JavaScript payload needs to be hosted by your web server. Credentials are submitted in a POST body directly to the RAS Secure Gateway, which validates them and responds with a redirect. Token creation, validation, and session handling are managed entirely by the User Portal Gateway — your integration never needs to inspect or manage JWT contents.

### Endpoint

```
POST <https://<user-portal-domain>>/userportal/auth-handoff
```

Where `<user-portal-domain>` is the IP address or FQDN of the RAS Secure Gateway. The **Enable User Portal** option must be enabled for the gateway in the Parallels RAS Console.

### How it works

1. The user signs in to your web portal, where the available published resources are listed.
2. The user clicks a resource (or your portal initiates sign-in to the User Portal).
3. The browser POSTs the handoff payload to the Gateway endpoint.
4. The Gateway validates the credentials and returns a `3xx` response, typically `302`.
5. The browser follows the redirect automatically to the User Portal destination — either the portal itself or, if **appid** was specified, the requested published resource.

### Your responsibilities

* Collect (or already have) the user's RAS username and password.
* POST the payload to the Gateway endpoint from the browser.
* Let the browser follow the returned `3xx` redirect automatically.

That is the full scope of the integration. Anything beyond the redirect session handling, token management, resource launching is handled by the User Portal.

{% hint style="info" %}
**Note**: If your frontend does not have access to the user's credentials, the POST can also be initiated from your backend. See [**Backend-Initiated Handoff**](/landing/ras-client-integration-guide/v21/ras-web-client-api/authentication-handoff-api/backend-initiated-handoff.md).
{% endhint %}

The payload structure is described in the [next section](/landing/ras-client-integration-guide/v21/ras-web-client-api/authentication-handoff-api/request-payload.md).


---

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