Skip to content
verify mcp Beta VerifyMCP is currently in beta. If you notice any issues, email [email protected] and we’ll put it right.

AtCoder MCP Server

REMOTE · API.KSRNYX.TOP · SCANNED AUG 3

Search AtCoder problems and fetch public problem statements through MCP.

Available components

+9 this week 65 Trust /100
Trust breakdown (6 categories)

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score →

Endpoint Security74
Transport & Reachability100
Schema Quality & AI Usability46
  • AI-judged instruction clarity (poor).Fail
  • Tool/resource definitions use about 173 tokens (~43/item across 4 items; 4 tools + 0 resources), lean.Pass
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management27
  • Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage71
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 0% of tool parameters carry a description.Fail
  • Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

Add this component to your MCP client. Where a client-specific snippet is available, pick your client below and copy it straight into your config; otherwise use the connection detail shown.

remote · api.ksrnyx.top

# add to Claude Code
claude mcp add --transport http ketherworks-atcoder https://api.ksrnyx.top/oj-mcp/atcoder/mcp
# ~/.codex/config.toml
[mcp_servers.ketherworks-atcoder]
url = "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "ketherworks-atcoder": {
      "type": "remote",
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp",
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add ketherworks-atcoder --url https://api.ksrnyx.top/oj-mcp/atcoder/mcp --transport streamable-http
# ~/.hermes/config.yaml
mcp_servers:
  ketherworks-atcoder:
    url: "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
// mcp.json
{
  "mcpServers": {
    "ketherworks-atcoder": {
      "type": "http",
      "url": "https://api.ksrnyx.top/oj-mcp/atcoder/mcp"
    }
  }
}

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 3 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

  • 1 Aug 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

  • 31 Jul 26 +5
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 29 Jul 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

  • 28 Jul 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

  • 27 Jul 26 0
    • We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
  • 26 Jul 26 56

    First indexed and scored.

Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 3 Aug 2026 · Probed https://api.ksrnyx.top/oj-mcp/atcoder/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=api.ksrnyx.top CN=YE1,O=Let's Encrypt,C=US 29 Jul 2026 27 Oct 2026 ECDSA 256 ECDSA-SHA384 6a7a5a686c72cd4427700cd9cfc905ebd66
SANs: api.ksrnyx.top
CN=YE1,O=Let's Encrypt,C=US (CA) CN=Root YE,O=ISRG,C=US 3 Sept 2025 2 Sept 2028 ECDSA 384 ECDSA-SHA384 5ddd70dd31f801c85c186a7a04b80afe
CN=Root YE,O=ISRG,C=US (CA) CN=ISRG Root X2,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 ECDSA 384 ECDSA-SHA384 872165fc34b6e5fba8add5b3705fb53a
CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) CN=ISRG Root X1,O=Internet Security Research Group,C=US 13 May 2026 2 Sept 2032 ECDSA 384 SHA256-RSA 6c8f1dc727c7117f7baf853ac980f9cd
DNSSEC insecure

Validation of api.ksrnyx.top. Not signed

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
top. present 26780 8 Verified
ksrnyx.top. absent Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation
Authentication No authorisation required

The endpoint answered without asking for a token. Anyone who knows the URL can reach it.

Result No authorisation required
HTTP status 200
Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://api.ksrnyx.top/oj-mcp/atcoder/mcp Verified 200
http (plaintext) http://api.ksrnyx.top/oj-mcp/atcoder/mcp HTTPS enforced 301 https://api.ksrnyx.top/oj-mcp/atcoder/mcp
MCP tools — 4 exposed · ~173 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability.

Tool Tokens
oj_capabilities ~22

Report the audited anonymous AtCoder read surface and explicitly unsupported operations.

Input schema present but exposes no named parameters.

Structured output declared, but exposes no named fields.

No examples provided.

oj_fetch_problem ~45

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.

Input schema present but exposes no named parameters.

Structured output declared, but exposes no named fields.

No examples provided.

oj_health ~24

Report local readiness and the latest observed AtCoder page-read status without probing upstream.

Input schema present but exposes no named parameters.

Structured output declared, but exposes no named fields.

No examples provided.

oj_search_problems ~82

Resolve exactly one contest/task id, atcoder:contest/task id, or canonical task URL. Free-text and catalog crawling are not supported.

NameTypeReqDescription
limitintegeryes
localestring
platformstringyes
querystringyes
requestIdstringyes
schemaVersionstringyes

Structured output declared, but exposes no named fields.

No examples provided.