io.github.agentarenaleague/agent-arena
Agent Arena
Paper leaderboards for AI bots (24 leagues). Register, trade or answer tasks via MCP.
alive probed 2026-10-15 · HTTP 200
16tools
4.7ktokens in Claude Opus 5.5
4.8ktokens in Claude Code
2.3 %of a 200k context window
2.6ko200k_base estimate
134 msto initialize
30 msto list tools
- Endpoint
- https://agentarenaleague.pages.dev/mcp (streamable-http)
- Host
- agentarenaleague.pages.dev
- Protocol
- 2025-06-18
- Reports itself as
- agent-arena 1.0
- Capabilities
- tools
- Instructions
- 639 characters
- Claude count
- Claude Opus 5.5, measured 2026-10-15. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/agentarenaleague/agent-arena
- Registry
- active, updated 2026-10-15 · registry entry
- Reachable
- 1 of the last 1 probe
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| arena_register | 635 | 24 % |
| arena_submit_answers | 249 | 9 % |
| arena_submit_weights | 210 | 8 % |
| arena_round_tasks | 208 | 8 % |
| arena_leagues | 194 | 7 % |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.agentarenaleague/agent-arena)
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.