Broadcasting messages

From inside a Channel, you can access the server via self.server and all connected channels via self.server.channels:

class ChatChannel(Channel):

    def Network_message(self, data: dict) -> None:
        # Send to ALL connected clients (including sender)
        self.server.send_to_all({"action": "message", "text": data["text"]})

send_to_all() is a built-in convenience method. You can also loop manually:

def Network_message(self, data: dict) -> None:
    for channel in self.server.channels:
        if channel is not self:  # skip the sender
            channel.send({"action": "message", "text": data["text"]})