Building Stubly: receipts and bookkeeping for x402 payments

x402 is making machine-native payments trivial — an agent hits an endpoint, pays a fraction of a cent, gets its response. Beautiful. But it quietly creates a new problem: if you're the one getting paid, you now have hundreds or thousands of tiny, agent-driven transactions a month that someone eventually has to turn into receipts, records, and something your accountant can actually use.

That's what we're building