Is it possible to post files to Slack using the incoming Webhook? : <p>I am trying out the Slack's API using the incoming webhook feature, posting messages works flawlessly, but it doesn't seem to allow any file attachments.</p>

<p>Looking through I understand I have to use a completely different OAuth based API, but creating more tokens just for the purpose of uploading a file seems odd when posting messages works well, is there no way to upload files to slack with the incoming webook?</p>
