> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/rest-client-step/options-rest-client/authentication-tab.md).

# Authentication tab

![Authentication tab in REST client](/files/Hfq6GOuuxEplWaPz5JBA)

If you need to authenticate with the resource, use the **Authentication** tab to enter the following details:

| Option            | Description                                                                                   |
| ----------------- | --------------------------------------------------------------------------------------------- |
| **HTTP Login**    | Specify the username required to access the resource.                                         |
| **HTTP Password** | Specify the password associated with the **HTTP Login** user name.                            |
| **Preemptive**    | Select to send the authentication credentials before a server gives an unauthorized response. |
| **Proxy Host**    | Specify the name of a proxy host, if proxy authentication is required.                        |
| **Proxy Port**    | Specify the port number of a proxy host, if proxy authentication is required.                 |


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