x402-tools-mcp

An MCP server that gives any AI agent six research and data tools, paid per call in USDC on Base through x402.

No API keys. No subscription. No monthly minimum. You pay a cent or two when your agent actually calls a tool.

Tool	Price	What it does
web_fetch	$0.01	Fetch a URL — status, final URL, title, cleaned text, top 20 links. For agents whose sandbox has no open-web access.
domain_intel	$0.02	RDAP registrar + creation/expiry dates, DNS records (A/MX/NS/TXT), Certificate Transparency history via crt.sh.
github_repo	$0.02	Repo facts: stars, forks, open issues, language, licence, last push, README excerpt.
token_intel	$0.02	ERC-20 facts read from Base mainnet: name, symbol, decimals, total supply, USDC balance.
repo_diligence	$2.50	Deep repo report — release cadence, contributor spread, issue/PR health, risk summary.
web_brief	$3.00	Multi-URL consolidated brief with per-source attribution.

Why this exists

Agent sandboxes are frequently firewalled from the open web, and the usual workaround — an API-key-gated scraping service — means a subscription, an account, and a monthly floor you pay whether or not you use it. x402 removes all three: the server answers 402 Payment Required, the client signs a USDC transfer authorisation, and the call proceeds. That is the whole handshake.

Setup

1. Fund a wallet. Any Base wallet with a few dollars of USDC. It needs no ETH — gas is paid by the settlement facilitator.

2. Export the key.

export X402_PRIVATE_KEY=0x<private key of that wallet>

3. Register the server with your MCP client:

{
  "mcpServers": {
    "x402-tools": {
      "command": "npx",
      "args": ["-y", "x402-tools-mcp"],
      "env": {
        "X402_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Or run it locally:

git clone https://github.com/foxxx009/x402-tools-mcp
cd x402-tools-mcp && npm install
X402_PRIVATE_KEY=0x... node index.js

Environment variables

Variable	Required	Default
X402_PRIVATE_KEY	yes	—
X402_BASE_URL	no	https://fitze-x402-seller.app.workbuddy.host

X402_BASE_URL lets you point the same server at your own x402 seller.

What leaves your machine

Only two things: the tool arguments, and an EIP-3009 signature authorising a USDC transfer for the quoted amount. The private key never leaves the process. Signing is local; settlement happens on Base.

Notes

• Payments are USDC on Base mainnet. A testnet wallet will not work.
• Each call is charged on retry with X-PAYMENT; the 402 response always states the exact amount before you pay anything.
• repo_diligence and web_brief are priced higher because they do real multi-request work. Call them deliberately.

Remote MCP (zero install)

Prefer not to run anything locally? The same service is exposed as a remote Streamable HTTP MCP endpoint:

https://fitze-x402-seller.app.workbuddy.host/mcp

Add it to any MCP client (Claude Desktop, Cursor, etc.) as a remote server URL. free_url_check runs without payment; paid tools answer HTTP 402 with x402 payment requirements and settle in USDC on Base when an x402-capable client retries. Listed in the official MCP Registry as io.github.foxxx009/x402-tools-mcp.

Licence

MIT