title: Open direct message channel to a user with a Slack Workspace token?
body: <p>I'm working on a new <a href="https://api.slack.com/workspace-apps-preview" rel="nofollow noreferrer">Workspace app</a> for Slack. I have a use case where I need to send notifications to users in Slack, through a direct message (or IM). Since the <a href="https://api.slack.com/methods/chat.postMessage" rel="nofollow noreferrer">chat.postMessage</a> endpoint requires a channel ID, I can get the existing IM channels using <a href="https://api.slack.com/methods/conversations.list" rel="nofollow noreferrer">conversations.list</a> and send them the notification.</p>
  
  <p>However, if the user hasn't yet opened an IM channel from their side, I need to create one. It seems that neither Web API endpoints (<a href="https://api.slack.com/methods/conversations.open" rel="nofollow noreferrer">conversations.open</a> or <a href="https://api.slack.com/methods/im.open" rel="nofollow noreferrer">im.open</a>) support Workspace tokens. I keep getting <em>not_allowed_token_type</em> error response. I can create a public channel with <a href="https://api.slack.com/methods/conversations.create" rel="nofollow noreferrer">conversations.create</a>, but that's not what I need.</p>
  
  <p>Is there another to open an IM channel to a user when using a Workspace token?</p>