Unfurl card from a private board

[Sean Xiang]

Hi Trello team, 

We are trying to send a card link from our custom app and unfurl it through the Trello Slack integration. We were able to do it in the past by post the URL of the card to the channel using chat.meMessage Slack API method. But recently we've changed the board owning the card to a private board, and based on the doc here: https://help.trello.com/article/1049-slack-app, we changed our message to /trello link-to-card-url.

However, for some reason the message still won't get unfurled by the Trello app in Slack. In the screenshot below, the first message sent by "Sean" is actually sent from our custom app, and the second message is I manually copy & paste the previous message, which can be unfurled by the Trello app. 

Is there an alternative way to send a card from a private board and have it unfurled by the Trello app through custom app? Appreciate any insights of possible root cause or solution. Thank you!

Kind regards, 

Sean

[Garrett]

Hey Sean,

Hm, I suspect this could be due to the app invoking the /trello command rather than a normal user. I can't say for certain if this is a limitation with Slack itself or something with our App specifically.

To take a closer look though, can you send us a message over at https://trello.com/contact please?