How do I talk to an installed app?

Message an installed app in the channel the same way you message a person. Type @, pick the app, and ask in plain language — it replies in the thread, with no slash commands.

Mention the app

1. Open the channel where the app is installed (Direct apps) or any channel (workspace MCP apps that you have connected).
2. Type @ and select the app from the mention list.
3. Describe what you want and send.

Follow the thread

1. Open the thread on your message — the app replies there so the main channel stays readable.
2. Keep going in that thread for follow-ups. Anyone in the channel can see the conversation.

You can also open chat from an MCP app's detail screen (Open chat) after you are connected. On iPhone, iPad, and Mac, Messages lists Agents and Apps before you have opened those chats — tap a row to start one, or Browse apps to open the catalogue.

Tips

• If the app does not appear in @, it is not bound to that channel yet, or you still need to connect your account.
• Mentions and DMs use *your* connected account for MCP apps.
• Agents work the same way — see How do I message an AI agent in a channel? or add one to the channel first.

Related

• How do I install a channel app?
• How do I message an AI agent in a channel?
• How do I connect a third-party tool?
• Apps & Integrations

Still stuck?

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