mcpbeat

AtCoder MCP Server

io.github.ketherworks/atcoder
answering

AtCoder MCP Server is answering right now. Last checked 9 min ago. It exposes 4 tools. Last commit 21 Jul 2026.

Search AtCoder problems and fetch public problem statements through MCP.

Uptime history 42 hours of history
42 hours agonow
100.0%
Uptime 24h
91 of 91 checks
4
Tools
read from the server
601 ms
Response time
average over 24h
0
Stars
last commit 21 Jul 2026

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 9 min ago.

run in your terminal
claude mcp add atcoder --transport http https://api.ksrnyx.top/oj-mcp/atcoder/mcp
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "atcoder": {
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}
~/.codex/config.toml
[mcp_servers.atcoder]
url = "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
.cursor/mcp.json
{
  "mcpServers": {
    "atcoder": {
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}
.vscode/mcp.json
{
  "mcpServers": {
    "atcoder": {
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

Available tools 4

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

capabilities
oj_capabilities
Report the audited anonymous AtCoder read surface and explicitly unsupported operations.
health
oj_health
Report local readiness and the latest observed AtCoder page-read status without probing upstream.
problem
oj_fetch_problem
Fetch one public problem statement from an exact contest/task pair or canonical atcoder.jp task URL. Returns sanitized HTML with preserved math, samples, limits, hashes, and source provenance.
problems
oj_search_problems
Resolve exactly one contest/task id, atcoder:contest/task id, or canonical task URL. Free-text and catalog crawling are not supported.

Endpoints

URLTransportStateLatencyChecked
https://api.ksrnyx.top/oj-mcp/atcoder/mcp streamable-http answering 622 ms 9 min ago

AtCoder MCP Server — questions

Answers built from our own checks of this server.

What can AtCoder MCP Server do?
It exposes 4 tools, read directly from the server on our last check. Among them: oj_capabilities, oj_fetch_problem, oj_health, oj_search_problems. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →
Is AtCoder MCP Server working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 601 ms. The bar chart above shows every period we have measured.
How do I connect AtCoder MCP Server?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does AtCoder MCP Server need an API key?
No. AtCoder MCP Server completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 4 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is AtCoder MCP Server?
It answers our handshake in 601 ms on average, which is faster than 16% of all working MCP servers we measure. That is on the slow side — worth knowing if the tool sits inside an interactive loop. The comparison comes from our own checks across the whole registry, every 15 minutes.
Is AtCoder MCP Server open source?
Yes — it is published under the MIT licence, written in TypeScript and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.