Basecamp OAuth flow not accepting redirect_uri query parameters
<p>It seems like the OAuth2 <code>redirect_uri</code> for Basecamp does not accept optional parameters (e.g. <code>mydomain.com/callback?user_id=1</code>). In fact, it only matches on the <em>exact</em> <code>redirect_uri</code> that I've provided when registering my app. Because of this, I am unable to identify the authenticated user when receiving the redirect. </p>

<p>Is this intended? If so, how can I uniquely identify my user on redirect? </p>

<p>One possibly solution is to use the <code>state</code> parameter as a identifier - however, this doesn't seem like the best solution.</p>