During the user authentication process, the opened website tells me that something is wrong with a redirect URI!

The service you are using is authenticating via the OAuth 2.0 protocol. Please check that the service you are using has the redirect URI set to the same value you pass to the service constructor. You can change this setting in the same place where you got your client identifier and client secret.

How do the SDKs handle expired tokens when dealing with OAuth?

Whenever an access token is retrieved, an expiration time and a refresh token are stored with it. Before every use of the access token, we check if it is expired and if so, use the refresh token to get a new access token to proceed with.

Which version of the API of service X are you using?

We are always using the latest stable version of all the APIs and update when a new version comes out.

Which versions of the Node.js runtime are supported?

We support Node.js starting from version 4.