Why redirect_uri is needed when client_id is supplied?

[lxdthriller]

we know that we need to pass both client_id and redirect_uri in the request. But isn’t that client app already registered its redirect url in authorization server? so that only client_id is needed so authorization server can look up the client_id and retrieve redirect_uri automatically?

[dawid.matuszczyk]

Hi @lxdthriller

Welcome to the Auth0 Community!

During a user’s authentication, the redirect_uri request parameter is used as a callback URL. In your application can specify multiple callback URL and with this parameter you can specify to which url user will be redirected after authentication.

Redirect Users

Thanks
Dawid

[lxdthriller]

Hi Dawid, isn’t that Auth Server can get pre-registered return url on client id? so why still need to pass return_url?