x402 Wallet MCP Server

What the code does

We read the source, 19 h ago · rules 3dff92dd89df

A value the model can set ends up inside a file or shell call. That is not a flaw by itself — for a terminal server it is the job — but it is where things go wrong when it is not.

        await fs.writeFile(out, bytes);

Things with no honest explanation: a promise that contradicts the code, code that runs at install time while hiding what it does, data leaving the machine.

        'http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token',

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

        const r = await redis.eval(

                return JSON.parse(await readFile(path.join(base, rel), 'utf8'));

    const child = spawn(command[0], command.slice(1), { stdio: 'inherit', shell: false });

        exec(compile(job["code"], "<three-ws-blender-mcp>", "exec"), namespace)

    const drop = STANDING_HIP_HEIGHT * (root.height - 1) + root.rise;

            if (reset) { state.cursor = null; state.total = 0; grid.innerHTML = skeletons(); stateEl.hidden = true; }

        `https://api.telegram.org/bot${cfg.token}/sendMessage`,

    'UklGRmQBAABXQVZFZm10IBAAAAABAAEAQB8AAIA+AAACABAAZGF0YUABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA…

    <script type="module" src="https://three.ws/agent-3d/latest/agent-3d.js"></script>

Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add x402-mcp -- npx -y @three-ws/x402-mcp

{
  "mcpServers": {
    "x402-mcp": {
      "args": [
        "-y",
        "@three-ws/x402-mcp"
      ],
      "command": "npx"
    }
  }
}

[mcp_servers.x402-mcp]
command = "npx"
args = ["-y", "@three-ws/x402-mcp"]

{
  "mcpServers": {
    "x402-mcp": {
      "args": [
        "-y",
        "@three-ws/x402-mcp"
      ],
      "command": "npx"
    }
  }
}

{
  "mcpServers": {
    "x402-mcp": {
      "args": [
        "-y",
        "@three-ws/x402-mcp"
      ],
      "command": "npx"
    }
  }
}

This one needs environment variables set before it will start: SOLANA_SECRET_KEY (Base58 (or JSON byte-array) Solana secret key that signs payments and holds the USDC. Not needed for the read tools (find_services, inspect_endpoint, or x402_wallet with an explicit address). Treat like cash.), SOLANA_RPC_URL (Solana mainnet RPC endpoint. Defaults to the public cluster — bring your own (Helius / Quicknode / Triton) for production traffic.), MAX_PAY_USD (Max USD a single pay_and_call may spend. Bounds a runaway or injected payment.), REQUIRE_CONFIRM (When on (default), pay_and_call refuses until re-issued with confirm:true. Set 0/false to disable the gate.), THREE_WS_BASE (Base URL of the three.ws API that serves /api/bazaar/search for find_services. Override only when self-hosting.). The author declared them in the registry entry; get the values from the project itself.