A chess-playing skill that uses a stateful server to manage one active online game.

Use it to join a user-created match, inspect the board, choose legal moves, make moves, wait for the opponent, or resign.

It gives the agent the game state and legal moves needed to play without losing track of turns or position.

How alexup71rus/Chess-and-MCP-Arena configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to alexup71rus/Chess-and-MCP-Arena. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/alexup71rus/Chess-and-MCP-Arena/main/.agents/skills/chess-play/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/alexup71rus/Chess-and-MCP-Arena

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/alexup71rus/chess-and-mcp-arena/chess-play/github.svg)](https://agentmods.dev/skills/alexup71rus/chess-and-mcp-arena/chess-play)

Your own site

<a href="https://agentmods.dev/skills/alexup71rus/chess-and-mcp-arena/chess-play"><img src="https://agentmods.dev/badge/skills/alexup71rus/chess-and-mcp-arena/chess-play/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/alexup71rus/chess-and-mcp-arena/chess-play"><img src="https://agentmods.dev/badge/skills/alexup71rus/chess-and-mcp-arena/chess-play.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 925 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00052	$0.00925
Opus 5.5	$0.00021	$0.00370
Sonnet 5.5	$0.00010	$0.00185
Haiku 4.5	$0.00005	$0.00093

Measured 2mo ago against content hash be0f97bdf79a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

chess-play scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/chess-play/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

chess-play: шахматы через MCP

В проекте всегда существует не больше одной активной online-партии. Её создаёт пользователь в UI на http://127.0.0.1:5173; агент не создаёт и не сбрасывает матч. MCP работает на http://127.0.0.1:5173/mcp и закрепляет сторону за текущей MCP-сессией.

Основные правила также приходят через поле instructions ответа MCP initialize, поэтому их получают клиенты, которые не обнаруживают repository skills.

Перед игрой

Проверьте GET http://127.0.0.1:5173/health. Если сервер не отвечает, попросите пользователя запустить pnpm dev. Не запускайте долгоживущий dev server без явного разрешения.

Пользователь должен сначала выбрать режим и начать матч в браузере. Если tool сообщает, что активной партии нет, попросите пользователя создать её через UI.

Инструменты

Tool	Назначение
`join_game({color?})`	Закрепить за MCP-сессией агентскую сторону.
`get_state()`	Увидеть режим, очередь, статус, историю, FEN и доску.
`legal_moves({from})`	Получить легальные ходы выбранной своей фигуры.
`make_move({move, promotion?})`	Сделать ход за закреплённую сторону.
`resign()`	Сдаться за закреплённую сторону.

Вход в матч

Человек против агента

Вызовите join_game() без цвета. Сервер автоматически закрепит единственную агентскую сторону и вернёт, играете вы белыми или чёрными.

Агент против агента

Первый агент выбирает свободную сторону: join_game({color:"w"}) или join_game({color:"b"}).
Второй агент вызывает join_game() и получает оставшуюся сторону.

Нельзя занять сторону человека, уже занятую сторону или сменить цвет в рамках той же MCP-сессии. После создания пользователем новой партии вызовите join_game снова.

Read the full file on GitHub · 80 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 80 lines · 52 tokens per session scan A be0f97bdf79a

Subscribe to this mod's changes

chess-play is a skill published in the GitHub repository alexup71rus/Chess-and-MCP-Arena (0 stars, last pushed 3mo ago), licensed MIT. It adds 52 tokens to every session and 925 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Game development

chess-play next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
chess-playalexup71rus/Chess-and-MCP-Arena	Skill	0	3mo ago	MIT	A	52	Claude Code, Codex
playtest-reportDonchitos/Claude-Code-Game-Studios	Skill	38k	yesterday	MIT	A	20	Claude Code
godot-signals-groupsgamedev-skills/awesome-gamedev-agent-skills	Skill	8.2k	yesterday	Apache-2.0	A	95	Claude Code
texture-workflowarjun988/blender-skills	Skill	2.4k	5d ago	MIT	A	41	Claude Code
scenario-unreal-gameplayscenario-labs/skills	Skill	3.7k	yesterday	MIT	A	121	Claude Code
motionOpenDCAI/GameFactory-3A	Skill	1.0k	13d ago	Apache-2.0	A	0	Claude Code, Codex
unity-addressablesBesty0728/Unity-Skills	Skill	1.9k	yesterday	MIT	A	25	Claude Code, Codex

Chess-and-MCP-Arena: Skill for Claude Code