x402

x402 revives the long-dormant HTTP 402 Payment Required status code as a real payment protocol: pay per request, in stablecoin, verified and settled on-chain — no accounts, no API keys, no invoices. It is also permissionless: no allowlist, no registration, nobody to ask. Anyone can charge for a service, and anyone can pay for one.

Every x402 exchange has three roles:

• Buyer — pays for a resource, signing an authorization rather than sending a transaction themselves.
• Seller — sets a price, gets paid, delivers the resource.
• Facilitator — verifies the buyer's payment and settles it on-chain, so the buyer and seller never have to trust each other directly.

This site runs all three: a facilitator, two paid endpoints acting as sellers, and the buyers that call them — the AI Image Generator and the assistant, which pay for every request you make from them. Because nothing here is gated, you can point your own seller at that facilitator instead of running one yourself.

• Accept payments (sellers)Integrate the facilitator into your API — quick start, fee model, and the full API reference.
• Pay for services (buyers)Call the two live x402 endpoints from TypeScript — the exact scheme and batch-settlement.

Links

• x402 documentation — the standard, from the x402 Foundation
• Reference implementation
• This site's facilitator, in full