farebox-mcp

Farebox MCP Server — connect Claude Desktop, Cursor, or any MCP-compatible agent to all 36+ frontier LLMs via Farebox. Pay per token in USDC on Solana. No accounts required for x402 keyless mode.

Quick Start

1. Download

# macOS / Linux
curl https://api.farebox.fun/api/mcp-server -o ~/farebox-mcp.js

# Windows (PowerShell)
Invoke-WebRequest https://api.farebox.fun/api/mcp-server -OutFile farebox-mcp.js

2. Add to Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "farebox": {
      "command": "node",
      "args": ["/Users/YOUR_USERNAME/farebox-mcp.js"],
      "env": {
        "FAREBOX_API_KEY": "sk-fbx-your-key-here"
      }
    }
  }
}

Get your API key at farebox.fun/dashboard.

Add to Cursor

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "farebox": {
      "command": "node",
      "args": ["/Users/YOUR_USERNAME/farebox-mcp.js"],
      "env": {
        "FAREBOX_API_KEY": "sk-fbx-your-key-here"
      }
    }
  }
}

Modes

API Key mode (recommended)

Set FAREBOX_API_KEY — calls billed to your prepaid USDC balance.

x402 Keyless mode

Set SVM_PRIVATE_KEY (base58 Solana private key) — your agent wallet pays per call on-chain. No account needed.

{
  "env": {
    "SVM_PRIVATE_KEY": "your-base58-solana-private-key"
  }
}

Security: Your private key never leaves your machine. Farebox only receives the signed transaction signature.

Preview mode

Omit both keys — tools load and return 402 payment quotes without making real calls. Use to explore the catalog before funding a wallet.

Available Tools

| Tool | Description | |------|-------------| | list_models | All 36+ models with live pricing | | chat | Call any model with a messages array | | get_balance | Current USDC credit balance | | get_usage | Token usage and cost breakdown | | call_skill | Call a built-in skill from the marketplace |

Supported Models

36 models across 14 providers: Anthropic, OpenAI, Google, xAI, Moonshot, DeepSeek, Meta, Mistral, Alibaba, Tencent, Cohere, Perplexity, Microsoft, and more.

Links

• Farebox Dashboard
• Farebox Docs
• API Reference
• x402 Protocol

License

MIT