Multiplayer AgentMake any game multiplayer with one key.
No servers, no netcode, no code. Build with your AI agent, share a link, and play with friends in seconds.
Free for your first 1,000 players a month. No card required.
Try it
Two clients, one room
Below are two separate browser documents that have never met. Open the room and they share one game: move your square, collect the dots, and watch the other side agree about the score. Nothing here is a recording, and nothing here is a stranger — both clients are yours.
Two documents · one channel · 90 ms of simulated latency, added on receive. Your own square moves at once and the other side arrives a moment later, which is what the real thing feels like. Both panes are running in your own browser — this demo needs no server, so it cannot reach anyone else’s. In your game the second player is on someone else’s machine and the latency is measured rather than invented.
How it works
Your agent does the build. You describe the game.
You do not write the netcode, and you do not write the client either. Your AI agent connects to our MCP server, and from there it can create the game, define the room and generate a working client that already talks to it. There is no server to write and nothing to deploy on your side.
Connect your agent
Paste one config block into Claude Code, Cursor, or any MCP client. That hands your agent our tool server and your key, once.
Describe the game
The agent calls the tools: it creates the game, declares what a room holds, and writes the client against the real reference. You review, you do not type.
Play it, share it
It opens in your browser already multiplayer. Send the link and a friend is in the room with you.
What you get
Everything a game needs, already built
Multiplayer is the hard part, and it is rarely the only part. These are the pieces you would otherwise assemble from three vendors and a weekend.
Real-time
Everyone sees the same game, instantly
Set a field on your own player and every other browser in the room has it. Rooms are created the moment someone joins one, so there is nothing to provision, name in advance or tear down afterwards.
- One generic room hosts every game, so a new game is just a new room name
- A client can only write its own player, which makes the usual cheat impossible by construction
- Reconnects are handled for you: a dropped phone resumes its seat instead of respawning
Fair play
Rules the browser cannot argue with
The moment a score matters, someone will open the console and try to write to it. Move the rules server-side and clients send inputs rather than outcomes, so the score is decided somewhere they cannot reach.
- Deploy game logic without running a server, a container or a deploy pipeline
- Every deploy is versioned, with one-call rollback when a change goes wrong
- Errors are collected and readable without joining the room to reproduce them
Players and saves
Progress that survives a lost phone
Players start anonymous, because asking for a signup before the fun is how you lose them. When they care enough to keep something, they claim a username and their progress follows them to any device.
- Anonymous first, with an optional username and password claim later
- Saves, stats and inventory stored per player, scoped to your studio or a single game
- Leaderboards with the scoring mode you pick, per game or across everything you run
Player-made content
Let the players build the levels
The cheapest content in your game is the content your players make. Publishing, browsing, voting and moderation are already built, so a level editor is a weekend rather than a quarter.
- Per-game libraries so one studio's content never leaks into another's
- Only claimed players can publish, which keeps drive-by spam out
- Moderation tools and per-plan caps included rather than bolted on
Monetization
Sell something without wiring a backend
Take a payment and the unlock is granted by a verified webhook into a store the client cannot write to. What the player bought is a fact on the server, not a flag in their browser.
- Checkout in one call, with the catalog defined server-side
- Entitlements live in a read-only namespace, written only by the payment webhook
- Nothing to configure in a payment dashboard before your first sale
Advertising
Your ad slots, all of your revenue
Drop your own publisher id into a game and the SDK reference tells your agent exactly how to place the units. We do not sit between you and the ad network, and we do not take a share of it.
- Bring your own ads id, per game
- A concrete recipe for interstitials and opt-in rewarded video
- One hundred percent of the ad revenue stays with you
Many games, one studio
Run a catalogue, not a pile of projects
One account holds every game you make, each with its own key, settings, players and analytics. Add the next one from the dashboard or ask your agent to create it while you are still describing the idea.
- A publishable key per game, managed in one place
- Per-game analytics: sessions, retention, concurrency and client errors
- Invite your team with read, write or admin roles
Pricing
Pay for players, not for servers
Priced on monthly active players, the one number you can predict for your own game. A traffic spike costs nothing extra and a quiet month costs nothing at all.
Every feature on this page is on every plan, including the free one. Paying raises the limits, it never unlocks a capability.
Fit
What this is good at, and what it is not
A strong fit
- Turn-based games: chess, cards, word and board games
- Casual and co-op: party games, trivia, drawing, puzzles
- Arena and .io games with dozens of players in one room
- Anything you want playable from a shared link, on a phone
Look elsewhere
- Competitive twitch games needing prediction and rollback
- Native Unity or Unreal builds, since the SDK targets the browser
- Games built on hidden information, unless the secret stays in server logic
- Shared, contested physics simulation
We would rather you find that out here than after a weekend of building. The comparison guide goes through how to choose, including when the answer is somebody else.
Keep reading
Start here
Add multiplayer to a game you already have
The whole integration, in about twenty lines.
Read it →Build an .io game
What the genre needs, and the order to build it in.
Read it →Build one with an AI agent
Describe the game, review the parts that matter.
Read it →Coming from Photon
What changes, and where Photon is still the better answer.
Read it →The full SDK reference
Every call, with snippets that run on paste.
Read it →Questions people actually ask
Limits, cost, and what to reach for when.
Read it →Have something playable tonight
The free tier does not expire and does not ask for a card. Build the whole game, share it with a friend, and only think about a plan once real players turn up.