API Authenticate options

Populair options on authenticating users on your API are:

• HTTP Basic Authentication
• HTTP Digest Authentication
• OAuth

Those three are most popular and widely used.

I will choose HTTP Basic Authentication for the moment with PHP Slim Framework. It is very simple to set it up with middleware and only one thing that needs to be pointed out here it needs to go over httpS (SSL)! Otherwise it can easily be inspected and reused maliciously.