The composer checks each network's real rules

The composer now checks each channel against that network's own rules. If X would reject a post (more than four images, or a video or GIF mixed with other media), it tells you before you schedule. If something would be left out, like a video on LinkedIn or Bluesky, you get a note on that channel instead of finding out later.

Character counters now count the way each network does: on X a link counts as 23 characters and emoji as 2. You also can't schedule a post for a time that's already passed. The same checks apply when you schedule from the agent, the API or an AI tool.