> ## Documentation Index
> Fetch the complete documentation index at: https://docs.alumio.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Set default headers of requests

> Set the default headers for requests.

Sets fallback header values for every request the connection sends. A default header is only applied when the request does not already have a header of that name, so anything set elsewhere on the request wins and these values fill in the gaps. Use this when you want a sensible standard value, such as a default `Accept` or `User-Agent`, while still letting individual requests override it.

This documentation describes: [Schema](/schemas/http-client-plugin-configurator/header-defaults)

## Fields

**Headers**

Optional

The default headers, entered as name and value pairs. Add a row for every header you want a fallback value for. Each value is only used when the request does not already set that header. To always force a value, use the Set request headers plugin instead.

## Sample data

This plugin fills in default headers on outgoing requests rather than transforming entity data, so there is no before/after to show. The example below sets a default `Accept` and `User-Agent` that are used only when the request has not already set them.

| Field | Value |
| - | - |
| Headers | `Accept` = `application/json`, `User-Agent` = `Alumio` |

```json Configuration theme={null}
{
  "prototype": "header-defaults",
  "parameters": {
    "headers": {
      "Accept": "application/json",
      "User-Agent": "Alumio"
    }
  }
}
```


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