Hypertext Application Language (HAL) is a convention for defining hypermedia such as links to external resources within JSON or XML code.
It is documented in an Internet Draft (a "work in progress"), with the latest version 11 published the 10th of October 2023.
[2] HAL was created to be simple to use and easily applicable across different domains by avoiding the need to impose any requirements on how the project be structured.
[citation needed] APIs that adopt HAL simplify the use of open source libraries and make it possible to interact with the API using JSON or XML.
[3] HAL is structured in such a way as to represent elements based on two concepts: Resources and Links.