title: Swift socket.io compatible version with server python-socketio
body: <p>I've searched couple of days for it but found nothing to fix this issue.</p>
  <p>My client is an iOS device running socket.io v15.2.0 (Oct 17, 2019).</p>
  <p>I've followed this post (<a href="https://medium.com/swlh/implement-a-websocket-using-flask-and-socket-io-python-76afa5bbeae1" rel="nofollow noreferrer">Implement a WebSocket Using Flask and Socket-IO(Python)</a>)</p>
  <p>That post described how to connect to the python socket server with a javascript client but even the javascript client has also returned same error :|</p>
  <p>Then I checked the compatibility table at <a href="https://github.com/miguelgrinberg/python-socketio" rel="nofollow noreferrer">this page</a> and found out that the latest version only works with the javascript client versions of 3.x so I checked <a href="https://cdnjs.com/libraries/socket.io" rel="nofollow noreferrer">this website</a> to see the latest version of javascript socket.io client and I changed the version to 3.0.4 then the JS client successfully connected to the python socket server .</p>
  <p>BUT, there is no versioning table for <strong>iOS clients</strong> at the swift socket.io <a href="https://github.com/socketio/socket.io-client-swift" rel="nofollow noreferrer">Github page</a></p>
  <p>Is there any versioning table for iOS/Android clients to show which <strong>python-socketio</strong> version is compatible with the v15.2.0 of swift socket.io clients?</p>
  <p>Error:</p>
  <pre><code>The client is using an unsupported version of the Socket.IO or Engine.IO protocols (further occurrences of this error will be logged with level INFO)
  127.0.0.1 - - [24/Dec/2020 13:29:15] &quot;GET /socket.io/?transport=polling&amp;b64=1 HTTP/1.1&quot; 400 -
  </code></pre>