basically working for one user (no user/all users actually)

lib/clip_web/live/board_live.ex

@@ -0,0 +1,38 @@
+defmodule ClipWeb.BoardLive do
+  use ClipWeb, :live_view
+
+  @impl true
+  def render(assigns) do
+    ~L"""
+      <form phx-change="paste">
+        <input type="text" name="snippet" value="<%= @snippet %>" data-updated-val="<%= @snippet %>" phx-hook="SnippetInput" autocomplete="off"/>
+      </form>
+      Current content: <%= @snippet %>
+      <button phx-click="normalize">
+    """
+  end
+
+  @impl true
+  def mount(_params, _session, socket) do
+    Phoenix.PubSub.subscribe(Clip.PubSub, "everybody") # actually only for single user
+    {:ok, assign(socket, snippet: "")}
+  end
+
+  @impl true
+  def handle_event("normalize", _, %{"snippet" => snippet} = socket) do
+
+    Phoenix.PubSub.broadcast(Clip.PubSub, "everybody", {:snippet_pasted, %{"snippet" => snippet}})
+    {:noreply, assign(socket, snippet: snippet)}
+  end
+
+  @impl true
+  def handle_event("paste", %{"snippet" => snippet}, socket) do
+    Phoenix.PubSub.broadcast(Clip.PubSub, "everybody", {:snippet_pasted, %{"snippet" => snippet}})
+    {:noreply, assign(socket, snippet: snippet)}
+  end
+
+  @impl true
+  def handle_info({:snippet_pasted, %{"snippet" => snippet}}, socket) do
+    {:noreply, assign(socket, snippet: snippet)}
+  end
+end

lib/clip_web/router.ex

@@ -17,7 +17,8 @@ defmodule ClipWeb.Router do
   scope "/", ClipWeb do
     pipe_through :browser
 
-    live "/", PageLive, :index
+    # live "/", PageLive, :index
+    live "/", BoardLive, :index
   end
 
   # Other scopes may use custom stacks.