Update README.md

README.md

@@ -249,6 +249,38 @@ Auth0
     }
 ```
 
+### Logging
+
+To enable Auth0.swift to log HTTP request and OAuth2 flow for debugging just add the following:
+
+```swift
+Auth0.enableLogging()
+```
+
+Then for a OAuth2 authentication you'll see in the console:
+
+```
+Safari: https://samples.auth0.com/authorize?.....
+URL: com.auth0.oauth2://samples.auth0.com/ios/com.auth0.OAuth2/callback?...
+POST https://samples.auth0.com/oauth/token HTTP/1.1
+Content-Type: application/json
+
+{"code":"...","client_id":"...","grant_type":"authorization_code","redirect_uri":"com.auth0.OAuth2:\/\/samples.auth0.com\/ios\/com.auth0.OAuth2\/callback","code_verifier":"..."}
+
+HTTP/1.1 200
+Pragma: no-cache
+Content-Type: application/json
+Strict-Transport-Security: max-age=3600
+Date: Thu, 09 Jun 2016 19:04:39 GMT
+Content-Length: 57
+Cache-Control: no-cache
+Connection: keep-alive
+
+{"access_token":"...","token_type":"Bearer"}
+```
+
+> Only set this flag for **DEBUG** only or you'll be leaking user's credentials in the device log.
+
 ## What is Auth0?
 
 Auth0 helps you to: