Some days I spend 2 hours chasing red herrings (like "perhaps my JSON ajax calls arn't running asynchronoously?") that turn out to be a simple one-word typo. This was one of them.

However, I did get the sidebar displaying alert messages, which can be easily sent to the user from any part of the assistant. This includes transient alerts of things it's doing, which disappear once the action finishes, and long-term alerts that are displayed until the user closes them. It even supports rendering arbitrary Yesod widgets as alerts, so they can also be used for asking questions, etc.

Time for a screencast!