Not at the moment. Once a message has been sent, it can't be deleted or unsent. The only thing you can do is click “Stop generating” to make the agent stop what it's doing.

So if you accidentally sent something sensitive, like a password or an API key, don't count on removing it from the chat. Go to the service it belongs to, revoke it there and generate a new one.

Also, if what you want to clear is all of an agent's conversation history rather than one message: deleting the agent does that. Archive it first, then go to “Space Settings → Archived Agents” and click “Delete”. All conversation history with that agent is removed permanently and can't be recovered. The steps are in this post: I created an extra agent by mistake, but there's no “Delete” in its menu. How do I remove it?