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mcp/harbor
Claude Desktop

x402 sms for Claude Desktop

io.github.ultrastarz/x402-sms

Pay-per-call MCP server. $0.03 USDC sends one transactional SMS to a US phone number via x402.

client:Claude Desktop transport:stdio runtime:npm

Install x402 sms in Claude Desktop

~/Library/Application Support/Claude/claude_desktop_config.json · windows: %APPDATA%\Claude\claude_desktop_config.json

Held in this page only — never stored, logged, or sent anywhere but back to your screen. 

{
  "mcpServers": {
    "x402-sms": {
      "command": "npx",
      "args": [
        "-y",
        "x402-sms-mcp"
      ],
      "env": {
        "BUYER_PRIVATE_KEY": "<BUYER_PRIVATE_KEY>"
      }
    }
  }
}

Settings → Developer → Edit Config opens this file. Restart the app after saving. Claude Desktop docs

x402 sms in other clients

x402 sms MCP server