Client Obtain Token

Pre Requirements

Initialize client first.

Code Flow

Code Flow would be the most basic flow to get an access token for server-side apps.

# Authorization Request
authorization_uri = client.authorization_uri(
  scope: [:profile, :email]
)
`open "#{authorization_uri}"`

# Authorization Response
puts "# Authorization Code"
code = gets.strip

# Token Request
client.authorization_code = code
client.access_token! # => Rack::OAuth2::AccessTokens subclass

rack-oauth2 uses Authorization header for Client Authentication as default.

If your OAuth Server doesn't support Basic Auth for Client Authentication and require including client_secret in request body, do

client.access_token! :body

Client Credentials Flow (a.k.a 2-legged)

Client Credentials Flow doesn't require any user interaction. Just call client.access_token!.

client.access_token! # => Rack::OAuth2::AccessTokens subclass

Resource Owner Credentials Flow

In this flow, your client will obtain end-user's password at the OAuth Server, directly.

This flow also doesn't need any redirect-based user interaction.

Simply set username & password to the client instance, and call client.access_token!.

client.resource_owner_credentials = 'username', 'password'
client.access_token! # => Rack::OAuth2::AccessTokens subclass