How to Monetize an MCP Server: Paid Tools with x402

The Model Context Protocol solved distribution for tools and left payment unsolved, because every payment system on the web assumes a human with a credit card completes a signup form. An autonomous agent has a wallet, not an inbox.

What the guide covers

• How to tell whether a capability is worth charging for, and how to price it in fractions of a cent.
• Wrapping a route so unpaid requests receive a real 402 Payment Required challenge, on Solana first with Base as a second accept.
• The ordering that keeps it honest: verify the payment, do the work, only then settle, so a failure charges nobody and a retry cannot double-charge.
• Charging per tool inside an MCP tools/call using the _meta payment convention, plus why every paid connector should ship one free explainer tool.
• Getting listed in the x402 bazaar where agents shop for paid capabilities, and proving an assistant can buy your service unattended with spend caps in place.

Every example is real and the production endpoint quoted in the article returns a live 402 you can inspect from a terminal in one line. Read it: three.ws/blog/monetize-mcp-server-x402-paid-tools