Any web game, multiplayer, with one line.

Joinable prototype: relay and SDK. Bubble Pop is an ordinary single-player game. This is the whole change:

  <canvas id="game" width="800" height="600"></canvas>
  <script src="game.js"></script>
+ <script src="/sdk.js" data-sync="game"></script>

Two players on one screen →Two separate players in the same room, side by side. Kart Loop: race online →Full multiplayer rounds: waiting room, countdown, live karts that bump, one podium, rematch. Press Race online, then Invite or Quick match. Bubble Pop: score attack →Everyone gets the same bubbles for 30 seconds; live scores, one leaderboard. Bubble Pop, multiplayer →Open it, press Invite, and open the link in another window or on your phone. Bubble Pop, the original →The unchanged single-player game, for comparison. Bubble Pop, connect on invite →Stays offline and keeps the address bar clean until you press Invite (data-connect="invite"). Star Catcher (avatars) →Held-key movement, made multiplayer by following the agent kit (Pattern B). Agent kit →What a game owner's coding agent reads to wire up a game. NOJU · prototype · not deployed