# Exceptions

This set of exceptions were introduced to describe the situations a bit more than just the `ValueError` usually raised.

`SocialAuthBaseException`
  Base class for all social auth exceptions.
`AuthException`
  Base exception class for authentication process errors.
`AuthFailed`
  Authentication failed for some reason.
`AuthCanceled`
  Authentication was canceled by the user.
`AuthUnknownError`
  An unknown error stoped the authentication process.
`AuthTokenError`
  Unauthorized or access token error, it was invalid, impossible to authenticate or user removed permissions to it.
`AuthMissingParameter`
  A needed parameter to continue the process was missing, usually raised by the services that need some POST data like myOpenID.
`AuthAlreadyAssociated`
  A different user has already associated the social account that the current user is trying to associate.
`WrongBackend`
  Raised when the backend given in the URLs is invalid (not enabled or registered).
`NotAllowedToDisconnect`
  Raised on disconnect action when it’s not safe for the user to disconnect the social account, probably because the user lacks a password or another social account.
`AuthStateMissing`
  The state parameter is missing from the server response.
`AuthStateForbidden`
  The state parameter returned by the server is not the one sent.
`AuthTokenRevoked`
  Raised when the user revoked the access_token in the provider.
`AuthUnreachableProvider`
  Raised when server couldn’t communicate with backend.

These are a subclass of `ValueError` to keep backward compatibility.