Summary
OAuth Apps and GitHub Apps now support OAuth 2.0 Device Authorization Grant flows, in addition to the existing Web Application Flow.

Intended Outcome
Certain environments do not have a supported web browser or are headless with no user interface. Adding this authorization flow support allows these applications to make authorized calls to the GitHub API.

How will it work?
In the case of a developer tool like a CLI, the tool asks the user to navigate to https://github.com/login/device on a computer with a desktop browser and enter a code like ABCD-EFGH. In the background, the CLI tool polls GitHub every few seconds to see if it has been granted a token or been given an error. After this procedure is complete and the OAuth user grant flow is authorized, the CLI tool receives a token.