MCP server for SWARM, an autonomous agent that sells small services over x402. Add it to Claude Code, Cursor, Claude Desktop or any MCP client. Your agent can then call SWARM's services and pay per call in USDC on Base. You need no account and no API key, and you are charged only when the service delivers.

Tools

Six tools. Each one calls SWARM's shop over the network and, with a wallet key, pays in USDC, so none is read-only; every tool declares this in its MCP annotations (readOnlyHint: false, openWorldHint: true):

Tool	What you send	What you get	Price
`code_health`	a public GitHub repo URL	static scan: TODO/FIXME debt, oversized files, secret heuristics, hygiene	$0.05
`summary`	a topic	one-page brief, researched on the live web, sources linked	$0.75
`report`	a topic	full Markdown report, researched on the live web, sources linked	$0.99
`utilities`	an operation (`uuid`, `hash`, `base64`, …)	UUIDs, hashes, base64, URL encoding, passwords, timestamps	$0.02
`site_check`	a URL	is it up: HTTP status, final URL after redirects, response time, TLS errors	$0.002
`read_page`	a URL	the readable text of the page (menus, scripts and markup removed)	$0.002

Install

You need Node.js 20 or newer. Use a dedicated wallet holding only a few dollars of USDC on Base for SWARM_WALLET_KEY.

Claude Code

claude mcp add --transport stdio swarm --env SWARM_WALLET_KEY=0x… --env SWARM_MAX_USD=1 -- npx -y swarm-x402-mcp

Cursor (~/.cursor/mcp.json) and Claude Desktop (Settings → Developer → Edit Config)

{
  "mcpServers": {
    "swarm": {
      "command": "npx",
      "args": ["-y", "swarm-x402-mcp"],
      "env": {
        "SWARM_WALLET_KEY": "0x…",
        "SWARM_MAX_USD": "1"
      }
    }
  }
}

SWARM_WALLET_KEY: the private key of the wallet that pays. Without it, the tools still list and quote; they explain the price and don't pay.
SWARM_MAX_USD (default 1): the server refuses any call priced above this, before signing anything.

How payment works

Each call first reads SWARM's 402 quote without paying. It checks that the network is Base mainnet and that the price is under your limit. Then it pays with the official x402 client (@x402/fetch). SWARM verifies the payment, does the work, and settles only if the work succeeded.