Paperwall od Fabricio

Paperwall is an open-source micropayment system that makes it easy for readers (humans and agents) to unlock content for just pennies. By using crypto (currently USDC on SKALE), payments can be as low as $0.01. It works for everyone: publishers get a single script tag, readers get a quick browser extension, AI agents use a batteries-included CLI tool or A2A server. It's that simple.