gistfile1.txt

[[RKObjectManager sharedManager].HTTPClient postPath:@"http://localhost:3000/api/v1/json/api_users/sign_in" parameters:params success:^(AFHTTPRequestOperation *operation, id JSON)
  {
    // Success
    [[NSUserDefaults standardUserDefaults] setValue:[JSON valueForKey:@"auth_token"] forKey:@"authentication_token"];
  } failure:^(AFHTTPRequestOperation *operation, NSError *error)
  {
    // Error
    NSLog(@"Error: %@", [error localizedDescription]);
}];