File Field

Illustrated drawing of Amadeus Maxmimilian StadlerIllustrated drawing of Amadeus Maxmimilian Stadler

Amadeus Stadler

Last updated June 30, 2023

The File field allows adding files to your content. You can use it to add files from anywhere in your repository and even restrict it to a specific folder.

Editing UI Widget

This field is displayed as a button labelled with the field’s label, which opens a file picker when clicked. Once a file was selected, its path will be visible along with an option to remove the file if the removable option is set to true.

Output Format

The File field outputs the path of the file in the current project as a string.


The following options are available for this field (default values shown):

  "removable": false,
  "allowUpload": false,
  "root": null,
  "filetypes": ["pdf", "zip"]
  • removable: whether or not the file may be removed after being set, resetting the field’s value to null

  • allowUpload: whether or not a new file may be uploaded using this file picker

  • root: the root folder from which to pick files, defaults to the root of the project, but may be any folder within it

  • filetypes: an array of file extensions without a leading dot that may be added to this field. For performance reasons, be aware that this only compares the extension of the file name!


The following validation options are available for this field (default values shown):

  "max": null,
  "required": false,
  "unit": "filesize (MB)"


If you are looking for a way to add an image to your content instead, the Image field is what you are looking for.

If the max value of the validation options is not set, the global maximum file size set in the media library options will be used instead, if set.

Setting the root option to the same directory as your Media Library will allow you and your collaborators to upload new files to the project by adding them to the Media Library without having to set allowUploads to true for the field itself. This will give you greater control about what role may do what via the Media Library Permissions.

Additionally, since version 0.6.0 of Mattrbld, it is also possible to add Media Collections, which allow for even more control and linking uploaded files via link-fields. You can learn more about them in the article about Media Collections.

Version History

  • Version 2: added a new option to enable / disable uploads through the file picker. Defaults to false. If you don’t upgrade your fields, your users will no longer be able to upload files straight from the file picker

  • Version at launch: 1