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Show HN: Playmat – Browser client for XMage, the open-source MTG engine

Developer arcanite24 released Playmat, a browser client and fork of the open-source Magic: The Gathering rules engine XMage that adds a WebSocket bridge to the server and an MTG Arena-style web interface. Playmat runs at playmat.deimos.studio, ships installers for Windows 10/11, macOS (Apple silicon and Intel) and Linux x64/ARM with Java bundled, and offers AI opponents, booster draft, sealed, Jumpstart and constructed tournaments, plus an optional single-player Career mode. The project is a hobby effort unaffiliated with Wizards of the Coast, merges from upstream XMage regularly, and is described by its author as a work in progress with rough edges.

read6 min views3 publishedOct 29, 2026
Show HN: Playmat – Browser client for XMage, the open-source MTG engine
Image: Michielbdejong (auto-discovered)

A fan-made web client for XMage, the open-source Magic: The Gathering rules engine. A hobby project, not affiliated with Wizards of the Coast.

Play online · Website · Download · Run a server · Working on Playmat · WebSocket API

Playmat is a fork of XMage, the open-source Magic rules engine with its cards, AI opponents, drafts and tournaments. It adds a WebSocket bridge to the server and a browser client styled after MTG Arena. Play it in your browser at playmat.deimos.studio, where the project runs a public server, install it on your computer to play the AI, Career or friends on your Wi-Fi, or run a server for a group that plays from anywhere. The engine stays XMage, merged from upstream regularly, so the cards it supports work here too.

It's a work in progress with rough edges. Bug reports and pull requests are welcome.

Come say hi, find a game or report bugs on the Discord server. If you'd like to help keep the server running, you can support the project on Ko-fi.

  • Playing. Pick a deck and play the AI, or send a friend an invite link. Practice mode gives you a goldfish opponent and tools to put any card in hand or on the battlefield.
  • The board. Attack arrows, a visible stack, priority shown on the table, auto-pass with the stops you choose, and keyboard shortcuts for passing and answering.
  • Decks. A deck builder with card search, and an import sheet that takes a link from Archidekt, Moxfield and other deck sites, a pasted list or a.dck file. Starter decks are there from the first sign-in, Commander ones included.
  • Events. Booster draft, sealed, Jumpstart and constructed tournaments. Empty seats fill with AI players.
  • Career. An optional single-player mode: five colour campaigns with a boss at the end of each, an Academy with a school for every format, puzzles, a gauntlet, sealed and draft runs, a weekly challenge, booster packs to open, a collection to craft into and achievements, illustrated with AI-generated art.
  • Social. Lobby chat, players online, profiles, a table browser, spectating, match history and replays.
  • Devices. Desktop browsers, tablets, an installable web app and an Android app that keeps card pictures on the device. English and Spanish.
  • On your computer. Installers for Windows, macOS and Linux with everything inside, Java included: install, open, play. Friends on the same network join from their browser.
  • Hosting. One Docker Compose stack: the server, Caddy with automatic HTTPS, a Scryfall picture cache, nightly backups and Discord notifications.

One download with everything inside, Java included. Install it, open Playmat, and the game opens in your browser. Play the AI and Career on your own, or have friends on the same Wi-Fi join you. Nothing else to install.

Your computer Download
Windows 10 or 11 Playmat-Setup-Windows-x64.exe : run it and pressInstall
Mac with Apple silicon (M1 and later) Playmat-macOS-arm64.dmg : drag Playmat to Applications
Mac with an Intel processor Playmat-macOS-x64.dmg : drag Playmat to Applications
Linux (x64 or ARM) curl -fsSL https://github.com/arcanite24/playmat/releases/latest/download/install.sh | sh

Prefer a terminal? These download the right file, install it and start Playmat, without the warnings below:

curl -fsSL https://github.com/arcanite24/playmat/releases/latest/download/install.sh | sh
irm https://github.com/arcanite24/playmat/releases/latest/download/install.ps1 | iex

The first time

  • Windows may say it protected your PC: choose More info , thenRun anyway . macOS may say it can't check Playmat: openSystem Settings ,Privacy & Security and chooseOpen Anyway . Playmat is a free fan project without paid signing certificates; the terminal installers above skip both screens.
  • The first start prepares the card database, which takes a few minutes once. Your computer may ask whether Playmat (Java) may accept network connections: allowing it lets friends on your network join.

Playing

  • A small Playmat window shows what's happening and opens http://localhost:17170 in your browser when the game is ready. Keep it open while you play; closing it stops the game.
  • Create an account the first time; it stays on your computer and unlocks Career. Untick Player accounts in the Playmat window to sign in with just a name instead.
  • Friends on the same network open the address the window shows, such as http://192.168.1.20:17170 .
  • Card pictures come from Scryfall, so an internet connection helps.
  • The window tells you when a new version is out. Installing it keeps your accounts, decks and Career progress.

Every version is on the releases page. ops/desktop/README.md covers how the app works, where it keeps its data and how releases are built.

You need Docker and a machine your players can reach.

cp ops/web/.env.example ops/web/.env      # set DOMAIN, XMAGE_AUTH, XMAGE_OWNER
docker compose -f ops/web/docker-compose.yml --env-file ops/web/.env up -d

This runs the published images, so nothing is built. The docs on the site walk through running a server and updating it: the admin console's Updates section says when a newer version is out, and with the updater turned on the owner installs it with one button.

Players open https://<your domain> and sign in. ops/web/README.md covers private LAN servers, running behind another reverse proxy, every setting, accounts and moderation, Discord notifications, backups and capacity.

To run it from source while you change it. Requirements: JDK 17 or later, Maven, and the Node.js version in Mage.Web.Client/.nvmrc.

mvn -T 1C -pl '!Mage.Client,!Mage.Server.Console,!Mage.Tests,!Mage.Verify,!Mage.Reports' install -DskipTests

cd Mage.Server/release
mvn -f ../../pom.xml -pl Mage.Server -Dexec.mainClass=mage.server.Main exec:java

cd Mage.Web.Client
npm ci
npm run dev

Sign in with any name. The client's own guide, Mage.Web.Client/README.md, covers its architecture, tests and the Android build (npm run android).

Path What lives there
Mage.Web.Client The Playmat client: React 19, TypeScript, Vite. Product brief in PRODUCT.md , design system inDESIGN.md .
Mage.Server XMage's server, plus the JSON-RPC WebSocket bridge and Career services ( src/main/java/mage/server/websocket ,.../career ).
ops/web The Docker Compose deployment kit.
ops/desktop The desktop app: a launcher and installers for Windows, macOS and Linux.
docs The WebSocket API, data models and the upstream merge recipe.
brand The Playmat logo, generated from the app's typeface by build_logo.py .
site The project website, published to GitHub Pages.
Everything else XMage: the rules engine, card implementations, AI, tests and the original desktop client.

Playmat stands on XMage and the many people who have built it since 2010: the rules engine, tens of thousands of card implementations and the AI are their work. Card and rules bugs usually live in the engine; XMage's issue tracker and wiki are the places for those. Card pictures and data come from Scryfall.

Released under the MIT License, like XMage.

Playmat is unofficial Fan Content permitted under the Fan Content Policy. Not approved/endorsed by Wizards. Portions of the materials used are property of Wizards of the Coast. ©Wizards of the Coast LLC.

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