farebox-mcp

Farebox MCP Server — connect Claude Desktop, Cursor, or any MCP-compatible client to 36+ frontier LLMs. Payments happen automatically per token in USDC on Solana — no accounts, no invoices.

npm version License: MIT

Install

npx farebox-mcp

No global install needed. Runs directly from the npm registry.

Quick setup

Claude Desktop

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

{
  "mcpServers": {
    "farebox": {
      "command": "npx",
      "args": ["-y", "farebox-mcp"],
      "env": {
        "FAREBOX_API_KEY": "sk-fbx-your-key-here"
      }
    }
  }
}

Cursor

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "farebox": {
      "command": "npx",
      "args": ["-y", "farebox-mcp"],
      "env": {
        "FAREBOX_API_KEY": "sk-fbx-your-key-here"
      }
    }
  }
}

Get your API key at farebox.fun/dashboard.

Keyless mode (x402)

No API key required — your agent pays per request autonomously in USDC on Solana:

{
  "mcpServers": {
    "farebox": {
      "command": "npx",
      "args": ["-y", "farebox-mcp"],
      "env": {
        "FAREBOX_SOLANA_PRIVATE_KEY": "your-base58-private-key",
        "FAREBOX_MODE": "x402"
      }
    }
  }
}

Available tools

Once connected, your agent has access to:

36+ frontier models — GPT-4o, Claude Sonnet, Gemini Flash, Llama, DeepSeek, Mistral, and more
Community skills — summarize, translate, code-review, explain, sentiment, extract-data, draft-email, fix-grammar

All models and skills appear as individual tools in your MCP client automatically.

Environment variables

Variable	Description
`FAREBOX_API_KEY`	API key from farebox.fun/dashboard
`FAREBOX_SOLANA_PRIVATE_KEY`	Base58 Solana private key (x402 keyless mode)
`FAREBOX_MODE`	`apikey` (default) or `x402`
`FAREBOX_BASE_URL`	Override API base URL (optional)

Pricing

Pay per token in USDC — no minimum, no subscription.

Model	Input	Output
llama-4-scout	$0.11 / 1M tokens	$0.34 / 1M tokens
gpt-4o-mini	$0.15 / 1M tokens	$0.60 / 1M tokens
claude-sonnet-4-5	$3.00 / 1M tokens	$15.00 / 1M tokens
gpt-4o	$2.50 / 1M tokens	$10.00 / 1M tokens

Full model list: farebox.fun/models

License

MIT