Mail Toll – Set a price on your inbox, agents pay USDC to reach you
x402 protocol integration lets agents pay via stablecoin or Stripe to bypass your spam filter.

Bitcoin micropayments kill spam economics, but adoption depends on senders willing to pay.
Bitcoin enthusiasts, spam-averse professionals, Lightning Network adopters
Earn.com (now Coinbase Earn) · Helios (paid email)
x402 protocol integration lets agents pay via stablecoin or Stripe to bypass your spam filter.
L402 turns Lightning payments into stateless API auth for autonomous agents.
Yet another Flask boilerplate, but the Strike API integration is a nice touch.
Zero-setup Lightning payment tester, but lacks depth beyond demo scenarios.
Agents finally have bank accounts: 402 interception + Lightning payments just works.
TEE-based key protection solves the always-online self-custody tension nicely.