Build a Paid MCP Server with x402 Micropayments: A Step-by-Step Tutorial

You want to build an MCP server that AI agents pay to use — per call, in USDC, no subscriptions, no invoices. Just: agent calls your tool, payment happens, response comes back. This tutorial walks through building a paid MCP server from scratch using x402 micropayments and mcp-billing-gateway for billing infrastructure. By the end, you'll have a working MCP server that charges $0.01 per tool call. What Is x402? x402 brings back HTTP's forgotten status code — 402 Payment Required . The flow is si