AtCoder MCP Server

Search AtCoder problems and fetch public problem statements through MCP.

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Remote HTTP

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "atcoder-mcp-server": {
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Documentation Overview

AtCoder MCP Server

简体中文

Find and read past AtCoder problems through MCP, locally or over hosted HTTP.

Quick Start

Add the hosted server to your MCP configuration:

config.json

{
  "servers": {
    "atcoder": {
      "type": "http",
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

The endpoint accepts anonymous read requests. It does not need an API key, Cookie, or judge account.

Then ask:

text

Fetch AtCoder problem abc086_a and show its samples.

What It Can Do

Tool	Purpose
`oj_capabilities`	Report the available AtCoder read operations and transport.
`oj_health`	Report process readiness and the latest upstream read.
`oj_fetch_problem`	Fetch one past problem by canonical URL or contest/task id.
`oj_search_problems`	Resolve an exact task URL or contest/task identifier.

Run Locally

Requires Node.js 22 or newer.

Terminal

npm ci
npm run check
npm run build
node packages/atcoder/dist/index.js

MCP client configuration from a source checkout:

config.json

{
  "servers": {
    "atcoder": {
      "type": "stdio",
      "command": "node",
      "args": ["/absolute/path/packages/atcoder/dist/index.js"]
    }
  }
}

Tagged GitHub releases attach a standalone npm tarball.

Availability

Hosted MCP: https://api.ksrnyx.top/oj-mcp/atcoder/mcp
Official MCP Registry: io.github.ketherworks/atcoder, described by server.json
Health status: see the repository homepage or call oj_health

Source and Safety

This standalone release is generated from the reviewed Competitive Programming MCP source. The release package bundles the shared OJ contract implementation, so its runtime does not depend on unpublished workspace packages.

Platform Rules

Do not use this server during ongoing ABC, ARC, or AGC contests. AtCoder's current generative-AI rules generally prohibit that use. This project is intended for practice with past problems. It is unofficial and is not affiliated with or endorsed by AtCoder Inc. Problem content remains subject to the AtCoder Terms of Use.

The server exposes no run or submit tool. It accepts no judge account credentials. See SECURITY.md for the security boundary and PROVENANCE.md for the canonical source revision.

Development

Terminal

npm ci
npm run check
npm run pack:check
npm run deploy:dry

License

Adapter source code is MIT licensed. Judge problem content and trademarks are not relicensed by this repository.

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about AtCoder MCP Server

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "atcoder-mcp-server": { "command": "npx", "args": ["-y", "AtCoder MCP Server"] } }

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Technical Specs & Signals

CategoryDeveloper Tools

36Quality signal: Fair · 36/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools15/30

Adoption & activity2/15

Community engagement0/10

A guidance signal from public completeness & health data — not a user rating. New listings start lower and rise as they add docs, get verified, and grow adoption. Signals we can't observe for a listing are skipped, not counted against it.

★ Featured

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More in 💻 Developer Tools →Best MCP servers for Developers →Alternatives to AtCoder MCP Server →Install in Claude Desktop Install in Cursor Install in VS Code

AtCoder MCP Server

Search AtCoder problems and fetch public problem statements through MCP.

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Remote HTTP

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "atcoder-mcp-server": {
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Documentation Overview

AtCoder MCP Server

简体中文

Find and read past AtCoder problems through MCP, locally or over hosted HTTP.

Quick Start

Add the hosted server to your MCP configuration:

config.json

{
  "servers": {
    "atcoder": {
      "type": "http",
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

The endpoint accepts anonymous read requests. It does not need an API key, Cookie, or judge account.

Then ask:

text

Fetch AtCoder problem abc086_a and show its samples.

What It Can Do

Tool	Purpose
`oj_capabilities`	Report the available AtCoder read operations and transport.
`oj_health`	Report process readiness and the latest upstream read.
`oj_fetch_problem`	Fetch one past problem by canonical URL or contest/task id.
`oj_search_problems`	Resolve an exact task URL or contest/task identifier.

Run Locally

Requires Node.js 22 or newer.

Terminal

npm ci
npm run check
npm run build
node packages/atcoder/dist/index.js

MCP client configuration from a source checkout:

config.json

{
  "servers": {
    "atcoder": {
      "type": "stdio",
      "command": "node",
      "args": ["/absolute/path/packages/atcoder/dist/index.js"]
    }
  }
}

Tagged GitHub releases attach a standalone npm tarball.

Availability

Hosted MCP: https://api.ksrnyx.top/oj-mcp/atcoder/mcp
Official MCP Registry: io.github.ketherworks/atcoder, described by server.json
Health status: see the repository homepage or call oj_health

Source and Safety

Platform Rules

The server exposes no run or submit tool. It accepts no judge account credentials. See SECURITY.md for the security boundary and PROVENANCE.md for the canonical source revision.

Development

Terminal

npm ci
npm run check
npm run pack:check
npm run deploy:dry

License

Adapter source code is MIT licensed. Judge problem content and trademarks are not relicensed by this repository.

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about AtCoder MCP Server

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "atcoder-mcp-server": { "command": "npx", "args": ["-y", "AtCoder MCP Server"] } }

AllMCPs Directory Badge

Full Badge Customizer

Showcase your server listing on GitHub or your project documentation. Embed this dynamic SVG badge to highlight official listing status and live engagement.

Badge Style:

Live Dynamic SVG Preview

Markdown (GitHub README)

[![AllMCPs](https://allmcps.com/api/badge/atcoder-mcp-server?style=directory)](https://allmcps.com/mcp/atcoder-mcp-server)

HTML Embed

<a href="https://allmcps.com/mcp/atcoder-mcp-server"><img src="https://allmcps.com/api/badge/atcoder-mcp-server?style=directory" alt="AtCoder MCP Server on AllMCPs" /></a>

Technical Specs & Signals

CategoryDeveloper Tools

36Quality signal: Fair · 36/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools15/30

Adoption & activity2/15

Community engagement0/10

★ Featured

AllMCPs Server

Explore Server →

Own this project?

Free dofollow backlink: add your website and place the AllMCPs badge on it — no claim needed. We detect it automatically and keep it verified as long as the badge stays live.

Claim & get free dofollow

Share & Embed

Add our SVG badge (dark/light directory styles) or embeddable widget to your site.

Explore more

More in 💻 Developer Tools →Best MCP servers for Developers →Alternatives to AtCoder MCP Server →Install in Claude Desktop Install in Cursor Install in VS Code