AMA: building an MCP server with x402 payments

I built Trip1 MCP and spent the last few months getting x402 to work end to end for hotel bookings. Happy to take questions on any of it.

Things worth asking about:

• How the x402 handshake actually runs inside an MCP tool call

• Why we settled on Base and USDC

• Supplier side: how a real hotel inventory system takes a transfer that wasn't signed by a human

• What breaks when an agent doesn't have a wallet loaded

• Why MCP rather than a REST API with API keys

• What I'd change about the x402 spec if I could

Drop a question, I'll work through them.