OAuth2 - Crystal 1.21.0

# module OAuth2

##
Overview

The OAuth module provides an `OAuth2::Client` as specified by RFC 6749.

NOTE To use `OAuth2`, you must explicitly import it with `require "oauth2"`

###
Performing HTTP client requests with OAuth2 authentication

Assuming you have an access token, you can setup an `HTTP::Client` to be authenticated with OAuth2 using this code:

    require "http/client"
    require "oauth2"

    # Here we use a bearer token, but it could be a mac token. We also set the
    # expires in value to 172,800 seconds, or 48 hours
    access_token = OAuth2::AccessToken::Bearer.new("some_access_token", 172_800)

    # Create an HTTP::Client
    client = HTTP::Client.new("api.example.com", tls: true)

    # Prepare it for using OAuth2 authentication
    access_token.authenticate(client)

    # Execute requests as usual: they will be authenticated
    client.get("/some_path")

This is implemented with `HTTP::Client#before_request` to add an authorization header to every request.

###
Obtaining access tokens

See `OAuth2::Client` for an example.

##
Defined in:

oauth2/auth_scheme.cr
oauth2/oauth2.cr