> For the complete documentation index, see [llms.txt](https://docs.does.qa/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.does.qa/test-steps/runner/set-header.md).

# Set Header

Set Header replaces every HTTP header on the active browser session with a JSON map you provide. Use it when the Flow needs a known header set before navigation or API traffic.

![Set headers Test Step](https://app.does.qa/screenshots/node/runner_header_set.png)

## When to use it

* Apply a full header bundle stored in a [Value](/values/value-store.md).
* Reset headers to a baseline before a sensitive journey branch.
* Pair with [Remove all headers](/test-steps/runner/remove-all-headers.md) when a later branch should start clean.

## Configure

### Basics

| Field       | What to set                                                                                    |
| ----------- | ---------------------------------------------------------------------------------------------- |
| **Headers** | JSON object of header names and values. Reference Values inside strings with `"{{valueName}}"` |

### Advanced

| Field                                 | What to set                                          |
| ------------------------------------- | ---------------------------------------------------- |
| **When should screenshots be taken?** | `Always` or `On Failures` (default)                  |
| **Status on fail**                    | [Failed Status](/test-step-options/failed-status.md) |

{% hint style="info" %}
**Pro tip:** Store reusable header JSON in Asset Values so staging and production differ only by the Value reference, not the step configuration.
{% endhint %}

## Related

* [Add header](/test-steps/runner/add-header.md)
* [Remove all headers](/test-steps/runner/remove-all-headers.md)
* [Runner](/test-steps/runner.md)

**Tags:** `runner`, `header`, `set`