Esben Petersen has posted the fourth part of his tutorial series covering the creation of a "modern REST API" with Laravel. In this latest article he focuses on authenticating users with the help of an OAuth2 flow.

OAuth is all around us. Most of us have tried to login to a 3rd party service using our Facebook or Google account as a login. This login mechanism is one of many OAuth authentication types. However, you can also use OAuth to generate simple API keys. One of the OAuth authentication types generates API keys based on username and password and is therefore a solid authentication choice for SaaS-style apps. This article will explore how to setup the password grant authentication type in Laravel using Laravel Passport.

The article is broken up into a few different sections, each with explanations and code where appropriate to help illustrate the point:

• a basic introduction to OAuth2 and grants
• authentication in single-page applications
• dependencies to use (and install/configuration)
• creating the login proxy
• building a consumer

The final step is an example (using a curl command) to test the API and ensure things are working as expected. The post ends with a more "real world" example of a Slack-style application and linking channels and user but only showing the channels users have access to based on scope.