go/internal/pusher/conn.go

@@ -44,8 +44,12 @@ func (c *Conn) ReadPump(ctx context.Context, hub *Hub) {
 			return
 		}
 
-		// Ignore keep-alive pings
+		// Respond to keep-alive pings
 		if string(data) == "ping" {
+			if err := c.ws.Write(ctx, websocket.MessageText, []byte("pong")); err != nil {
+				slog.Debug("websocket pong write error", "connId", c.id, "error", err)
+				return
+			}
 			continue
 		}
 

js/src/lib/pusher-client.ts

@@ -176,6 +176,9 @@ export class PusherClient {
   }
 
   private handleMessage(data: string): void {
+    // Ignore keep-alive pong responses
+    if (data === "pong") return;
+
     let msg: ServerMessage;
     try {
       msg = JSON.parse(data);