io.github.ketherworks/atcoder
AtCoder MCP Server
Search AtCoder problems and fetch public problem statements through MCP.
alive probed 2026-10-05 · HTTP 200
4tools
0.3 %of a 200k context window
626tokens, o200k_base estimate
539 msto initialize
145 msto list tools
- Endpoint
- https://api.ksrnyx.top/oj-mcp/atcoder/mcp (streamable-http)
- Host
- api.ksrnyx.top
- Protocol
- 2025-11-25
- Reports itself as
- atcoder-mcp-server 0.1.0
- Capabilities
- tools
- Instructions
- none
- Claude count
- The count_tokens endpoint refused the tool schemas: tools.3.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level. The estimate stands in.
- Repository
- https://github.com/ketherworks/atcoder-mcp-server
- Registry
- active, updated 2026-07-21 · registry entry
- Reachable
- 5 of the last 5 probes
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| oj_fetch_problem | 342 | 55 % |
| oj_search_problems | 172 | 27 % |
| oj_health | 57 | 9 % |
| oj_capabilities | 55 | 9 % |
History
We add a row when the result changes. A server with no change keeps its last row.
| Probed | Result | Init | Tools | Claude | o200k |
|---|---|---|---|---|---|
| 2026-10-05 00:36 | alive | 539 ms | 4 | 626 | |
| 2026-10-04 10:05 | alive | 3.2 s | 4 | 626 | |
| 2026-10-04 07:59 | alive | 1.9 s | 4 | 626 | |
| 2026-10-03 20:38 | alive | 1.5 s | 4 | 626 | |
| 2026-10-03 17:54 | alive | 1.0 s | 4 | 626 |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.ketherworks/atcoder)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.