Custom Skill

Custom Skill

A Custom Skill, or Box Skill is a type of application that performs custom processing for files uploaded to Box. Skills are designed to make it straightforward to use third-party Machine Learning services to automatically extract information from files uploaded to Box and apply the resulting data as metadata on the file.

Skills example

Custom Skills need to be enabled on a folder by a Box Admin. After this an event is sent to the Skill's application server every time a file is uploaded to the folder. This application can then download the file, inspect it or hand it off to a machine learning service, and write powerful metadata to the file.

Start building a Custom Skill

Authentication methods

Working with Custom Skills is simplified by the pre-authorized API credentials that are provided with every Skill Event. For this reason though, Custom Skills have limited API access. You do not need to select an authentication type to work with this type of application.

When to use

A Custom Skill is best used when the application:

  • Wants to only add metadata to files uploaded to Box
  • Does not want to upload new files or perform any other API calls
  • Wants to have way to pass files to Machine Learning services without having to handle authentication

Use cases

Example use cases for Custom Skills include:

  • A process that automatically extracts license plate details from images and writes the details back to the file as keywords.

  • A process that automatically detects faces in videos, and writes the timestamps at which these faces occur back to the file as a timeline.


Before a Custom Skill can be used it needs to be assigned to a folder for which the skill should trigger.

Learn how to approve Custom Skills