title: External link to existing Microsoft Teams chat
body: <p>I have developed a Microsoft Teams app, and I'm using 'deep linking' to create named chats (chats with topic names) with selected users, as per the docs:</p>
  <p><a href="https://docs.microsoft.com/en-us/microsoftteams/platform/concepts/build-and-test/deep-links#deep-linking-to-a-chat" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/microsoftteams/platform/concepts/build-and-test/deep-links#deep-linking-to-a-chat</a></p>
  <p>An example of a 'deep link' to create a chat would be:</p>
  <p><a href="https://teams.microsoft.com/l/chat/0/0?users=joe@contoso.com,bob@contoso.com,dave@contoso.com&amp;topicName=Prep%20For%20Meeting%20Tomorrow&amp;message=Hi%20folks%2C%20kicking%20off%20a%20chat%20about%20our%20meeting%20tomorrow" rel="nofollow noreferrer">https://teams.microsoft.com/l/chat/0/0?users=joe@contoso.com,bob@contoso.com,dave@contoso.com&amp;topicName=Prep%20For%20Meeting%20Tomorrow&amp;message=Hi%20folks%2C%20kicking%20off%20a%20chat%20about%20our%20meeting%20tomorrow</a></p>
  <p>This works fine - and if I save the portion of the link minus the 'message' portion, this again works fine, and links the user to the existing chat:</p>
  <p><a href="https://teams.microsoft.com/l/chat/0/0?users=joe@contoso.com,bob@contoso.com,dave@contoso.com&amp;topicName=Prep%20For%20Meeting%20Tomorrow" rel="nofollow noreferrer">https://teams.microsoft.com/l/chat/0/0?users=joe@contoso.com,bob@contoso.com,dave@contoso.com&amp;topicName=Prep%20For%20Meeting%20Tomorrow</a></p>
  <p>However, if another user is added to the chat from inside Teams itself, the link above will not link to the existing chat any more, rather create a brand new chat instance with the same topicName and originally specified users.</p>
  <p>Is there a way of 'deep linking' to a chat by it's topicName or some kind of ID only? Without having to get clever with the Microsoft Graph API?</p>
  <p><a href="https://teams.microsoft.com/l/chat/0/0?Prep%20For%20Meeting%20Tomorrow" rel="nofollow noreferrer">https://teams.microsoft.com/l/chat/0/0?Prep%20For%20Meeting%20Tomorrow</a>
  just links to the chat 'home screen', where a user can start a new chat through Teams</p>