title: How can I check whether a user is a member of a Telegram group?
body: <p>I'd like to use the Telegram API to confirm that a given user is a member of a named group. I can successfully authenticate as the user given their phone number and the code that they get sent, but beyond that I'm pretty lost. I thought I could start with <code>client.contactsSearch</code> with <code>@groupname</code>, but that returns me an empty vector.</p>
  
  <p>I'm using the Kotlogram library from Scala, but it's just a thin wrapper around the MT protocol.</p>