Smash&Clash Agent Plugin

Smash&Clash is a two-player strategy board game where every move matters. This repository is its Agent Plugin. It follows the Agent Plugins 1.0.0 standard, and works in Claude Code, Cursor, Codex and any other Agent Plugins client. It is also a Gemini CLI extension, and its skills install into every agent skills.sh supports.

What it lets an agent do:

• Play the game itself. It plays you or any person, another agent, the Smash&Clash house opponent, or whoever is in the quick-match queue. Since Smash&Clash 2.1.0 every client plays every other: a person on smashandclash.in, its Android, Windows, macOS and Linux apps, Telegram, a terminal or any SDK app can join the agent's room code (or open its invite link), the agent joins theirs, and the quick-match queue is shared by all of them (one game, every client).
• Host and watch. It sets up a match between two people, follows games live, and reads finished games as replays and Game Reviews.
• Get told instead of polling. On clients with MCP Events it subscribes to its turn, a game starting, every move and the result; apps get the same events as signed webhooks.
• Read anything pasted. resolve_link says what a room code or link from any client is, and which tool opens it.
• Look people up. Public player profiles, and club, Discord and Whop leaderboards.
• Send a human a Hosted Agent Challenge, powered by AgentsORG.
• Build your own client with the official card art, attack animation, sounds and fonts, plus public player profiles and club leaderboards.
• Use the SDK, the CLI or WebMCP.

In Claude Code, the bundled mod also lets you play while Claude works.

MCP     https://www.smashandclash.in/api/mcp    (Streamable HTTP, no auth, MCP 2024-11-05 to 2026-07-28)
Skills  npx skills add smashandclash/plugin
Setup   npx smashandclash mcp-config --client <your agent>     (--list for all 25)
Play    https://www.smashandclash.in

Install

Skills only (any agent: Claude Code, Codex, Cursor, OpenCode, ...)

npx skills add smashandclash/plugin            # pick skills and agents
npx skills add smashandclash/plugin --all      # every skill, every agent

Skill	Teaches an agent to...
play-smash-and-clash	Play a match itself over MCP: against a person on any client (a room code or an invite link), another agent, the house opponent (800-1600 ELO) or the quick-match queue; host a match for two people; watch, replays and reviews
hosted-agent-challenge	Send a human a Hosted Agent Challenge (powered by AgentsORG), then read back the verified result, ELO and history
smash-and-clash-sdk	Write code with @smashandclash/sdk: strategies, bots, duels, profiles and leaderboards
smash-and-clash-client	Build your own client or UI: follow the game's design system (smashandclash.design) or extend it with your own flavour, draw the cards from the official art, animate attacks, play the game's sounds and voices, show profiles and leaderboards
smash-and-clash-cli	Drive the smashandclash CLI from a shell: its --json envelope and exit codes
smash-and-clash-events	Subscribe to game and challenge events (your turn, moves, results) instead of polling, and verify the signed webhooks
smash-and-clash-webmcp	Play for the user in their browser through the page's WebMCP tools
smash-and-clash-setup	Get a new user from install to a first match (the onboarding skill ChatGPT and Codex run after install)

Claude Code

/plugin marketplace add smashandclash/plugin
/plugin install smash-and-clash@smashandclash        # the MCP server and the eight skills
/plugin install smash-and-clash-mod@smashandclash    # the mod: play while Claude works

Gemini CLI

gemini extensions install https://github.com/smashandclash/plugin

It adds the MCP server (gemini-extension.json) and a short context file (GEMINI.md).

Cursor and other Agent Plugins clients

Install this repository as a plugin:

• Cursor: Plugins → install from GitHub → smashandclash/plugin.
• Other clients: they read plugin.json, mcp.json and skills/.

Every other agent

Any agent that adds a remote MCP server can play. npx smashandclash mcp-config --client <id> prints its exact config:

Agent	--client	Agent	--client
Claude Code	claude-code	Amp	amp
Codex	codex	Factory Droid	droid
Cursor	cursor	Goose	goose
VS Code (GitHub Copilot)	vscode	Kiro	kiro
GitHub Copilot CLI	copilot-cli	OpenCode	opencode
Windsurf	windsurf	OpenClaw	openclaw
Gemini CLI	gemini	Hermes Agent (Nous Research)	hermes
Antigravity	antigravity	Trae	trae
Cline	cline	Zed	zed
Roo Code	roo	Kilo Code	kilo

Each one's file and fields: https://docs.smashandclash.in/connect/agents

Chat apps (custom connector)

These clients add a remote MCP URL rather than a plugin. It's the same server.

Client	Add it
Claude	Add Smash&Clash
ChatGPT	Settings → Apps & Connectors → Advanced → Developer mode → Create. Name Smash&Clash, URL https://www.smashandclash.in/api/mcp, no authentication. Work chats get events.
Grok	grok.com/connectors → New Connector → Custom → paste the URL
Poke	The published recipe: https://poke.com/r/4eP67qG4ou-

Then say "let's play Smash&Clash".

Play while Claude works (Claude Code mod)

smash-and-clash-mod is a Claude Code mod. /smash opens a Smash&Clash board in a pane beside the transcript, so you can play a move while Claude works.

• It works in the terminal and in the Desktop app.
• Your game is saved between sessions.
• While Claude works, a line above the prompt says it's your move.

Key	Does
1-5	Pick a card
w a s d	Move over the board
f	Play
g	Suggest a move
x	Stay put when a hop is offered
n	New game

Commands:

• /smash new starts a game against the house.
• /smash duel opens a duel; /smash join CODE joins one.
• /smash close closes the pane.

Settings live in /plugin configure smash-and-clash-mod@smashandclash:

• your name;
• the house strength (800-1600);
• whether the board opens when Claude starts working.

Mods need Claude Code 2.1.287 or later, where your account has them enabled.

What the agent does

Play. It calls start_game, or create_duel / join_duel (a room code, or its join link, from any client), then reads its hand, the board and the legal moves by name. It loops play_move (and wait_for_turn in a duel) to the end, and shares the replay link. Every position is rebuilt by the server, so only legal moves land.

Learn, look up, watch. get_rules, get_cards / get_card, resolve_link; get_player, get_leaderboard; get_featured_game, list_live_games, watch_game, get_replay, get_review. Every tool returns structured data with an output schema; a failure is a tool error with a code and a hint. Resources (the rules, the deck, a play guide, the event catalog, any card, game, replay or agent) and nine prompts (play-a-game, play-a-person, join-a-room, quick-match, host-a-match, watch-a-game, review-a-game, challenge-a-friend, learn-the-rules) come with the server.

Events. On clients with MCP Events it subscribes to game.turn, game.started, game.move, game.finished or challenge.played (events/subscribe) and is told by signed webhook, instead of polling.

Hosted Agent Challenges. It calls create_challenge with its own slug (claude, chatgpt, gemini, grok, copilot, perplexity, poke) and sends you the link. An agent hosted on Smash&Clash plays you on its behalf. Then it calls get_match_result for the verified result, and get_agent_profile / get_match_history for its record. Hosted agents are powered by AgentsORG.

Without MCP

• REST. OpenAPI 3.1 at https://www.smashandclash.in/openapi.json:
  • games under /api/v1/games (with the cards, the asset kit and webhook events at /api/v1/games/events);
  • players and leaderboards under /api/v1/players, /api/v1/clubs and /api/v1/leaderboards;
  • challenges under /api/v1/agent.
• SDK. npm install @smashandclash/sdk
• CLI. npx smashandclash. It's a full-screen game for humans, and --json for agents.
• Developer docs. https://www.smashandclash.in/developers

Package layout

plugin.json                              Agent Plugins 1.0.0 manifest (extensions.com.openai: the onboarding skill)
mcp.json                                 Agent Plugins MCP config (Streamable HTTP)
skills/<name>/SKILL.md                   eight Agent Skills
gemini-extension.json, GEMINI.md         Gemini CLI extension: the MCP server and its context
com.anthropic.claude-code/               Claude Code extension namespace
  smash-and-clash-mod/                   the mod (its own Claude Code plugin)
.claude-plugin/plugin.json, .mcp.json    Claude Code's manifest and MCP file
.claude-plugin/marketplace.json          Claude Code marketplace: the plugin and the mod
.cursor-plugin/plugin.json               Cursor metadata

There is no install script, and there are no secrets. The plugin talks to Smash&Clash's public API only.

MIT licensed. The license covers this plugin's files. The game's art, audio and characters stay Smash&Clash's: free to use in clients and apps built for Smash&Clash, never to present as your own.