x402 seller server

This app monetizes five routes with the x402 payment protocol:

• /protected — gated by the proxy.ts middleware (whole-route protection).
• /api/weather?city=... — gated per-route with withX402, fixed price (exact scheme, settles only after a successful response), backed by live weather data.
• /api/generate?prompt=... — gated per-route with withX402, usage-based pricing (upto scheme: buyer authorizes a max, server charges actual usage via setSettlementOverrides).
• /api/insights?topic=...&tier=... — gated per-route with withX402, exact scheme with a dynamic price: $0.001 standard, $0.005 premium, chosen per-request from a tier query param.
• /api/ping — gated per-route with withX402, batch-settlement scheme: many cheap calls accumulate in one payment channel, claimed and settled together by a scheduled job (/api/cron/settle) instead of once per request.

Requesting either one without a valid payment returns an HTTP 402 Payment Required with payment instructions. See the README for how to test the full flow.