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x402 Tools

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Pay-per-call research tools for AI agents, paid via x402 USDC. Remote MCP, one free tool.

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http x402-tools 'https://fitze-x402-seller.app.workbuddy.host/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "x402-tools": {
            "type": "http",
            "url": "https://fitze-x402-seller.app.workbuddy.host/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. x402-tools-mcp
  2. Why this exists
  3. Setup
  4. Environment variables
  5. What leaves your machine
  6. Notes
  7. Remote MCP (zero install)
  8. Licence

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.

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

VariableRequiredDefault
X402_PRIVATE_KEYyes—
X402_BASE_URLnohttps://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

Frequently asked questions

What is x402 Tools?

Pay-per-call research tools for AI agents, paid via x402 USDC. Remote MCP, one free tool.

How do I install x402 Tools?

It runs as a remote server. In Claude Code: claude mcp add --transport http x402-tools 'https://fitze-x402-seller.app.workbuddy.host/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does x402 Tools need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is x402 Tools open source?

Its code is public on GitHub, but the repository does not declare a standard license.

Who maintains x402 Tools?

It is published by foxxx009. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.