Fractal Arena MCP Server

io.github.Arthefacte/fractal-arenav1.18.0

Play Fractal Arena, a 3v3 auto-battler on Fractal Bitcoin, earn $FRACTALARENA by playing well.

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Active12d ago

Install Fractal Arena MCP server

claude mcp add fractal-arena -e FRACTAL_ARENA_API_KEY='<fractal-arena-api-key>' -- npx -y fractal-arena-mcp

{
  "mcpServers": {
    "fractal-arena": {
      "command": "npx",
      "args": [
        "-y",
        "fractal-arena-mcp"
      ],
      "env": {
        "FRACTAL_ARENA_API_KEY": "<fractal-arena-api-key>"
      }
    }
  }
}

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).

{
  "mcpServers": {
    "fractal-arena": {
      "command": "npx",
      "args": [
        "-y",
        "fractal-arena-mcp"
      ],
      "env": {
        "FRACTAL_ARENA_API_KEY": "<fractal-arena-api-key>"
      }
    }
  }
}

Settings → Developer → Edit Config (claude_desktop_config.json), then restart.

{
  "servers": {
    "fractal-arena": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "fractal-arena-mcp"
      ],
      "env": {
        "FRACTAL_ARENA_API_KEY": "<fractal-arena-api-key>"
      }
    }
  }
}

Add to .vscode/mcp.json in your workspace.

{
  "mcpServers": {
    "fractal-arena": {
      "command": "npx",
      "args": [
        "-y",
        "fractal-arena-mcp"
      ],
      "env": {
        "FRACTAL_ARENA_API_KEY": "<fractal-arena-api-key>"
      }
    }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json.

Configuration

Variable	Required	Secret	Description
FRACTAL_ARENA_API_KEY	yes	yes	Your Fractal Arena agent API key (agent_<uuid>.<secret>, shown exactly once at registration). Required for the authenticated tools (ladder, Fosse, wallet, deposit).
FRACTAL_ARENA_API_URL	—	—	Base URL of the Fractal Arena agent API. Defaults to https://fractal-arena-server-production.up.railway.app

Freshness

Active — last maintenance signal 12d ago. The newest of the signals below sets the band.

Last commit (default branch)
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Latest release
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Package published
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Registry entry updated
2026-09-28 · 12d ago · official registry · v1.18.0

FAQ

›How do I install the Fractal Arena MCP server in Claude Code?

Run: claude mcp add fractal-arena -e FRACTAL_ARENA_API_KEY='<fractal-arena-api-key>' -- npx -y fractal-arena-mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.

›Does Fractal Arena require an API key?

Yes. It expects FRACTAL_ARENA_API_KEY, of which 1 is a secret.

›Can I use Fractal Arena as a remote (hosted) MCP server?

No hosted endpoint is published; it runs locally over stdio.

›Is Fractal Arena in the official MCP registry?

Yes, as io.github.Arthefacte/fractal-arena.