# Headers tab

![Headers tab in REST client](/files/QeBa5UuirMKfsc9I1tl8)

Use the table in the **Headers** tab to define the content of any HTTP headers in an existing PDI field.

The headers table contains the following columns:

| Column | Description                                                             |
| ------ | ----------------------------------------------------------------------- |
| Field  | The field from incoming PDI stream that contains the header information |
| Name   | The name of the outgoing PDI field from this step                       |

Use the **Get fields** button to populate the table with fields from the incoming PDI stream.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/rest-client-step/options-rest-client/headers-tab.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.