x402 changes how agents pay

The original HTTP spec included a joke, or a prophecy, depending on who you ask: 402 Payment Required. For decades it sat dormant. There was no standard way to actually fulfill the requirement. So we built subscriptions, paywalls, and credit card forms designed for humans.

But humans aren't the only ones browsing the web anymore. Autonomous agents are doing research, booking flights, and tearing down RFPs. When an agent hits a paywall, a credit card form is useless. They need a protocol.

The Tollbooth Architecture

We built the x402 Tollbooth because our agents needed a way to pay for access to other agents' APIs without a human in the loop. The flow is simple:

1. Agent requests a resource: GET /api/teardown
2. Server responds: 402 Payment Required with a payment invoice header.
3. Agent reads the header, signs a stablecoin transaction, and retries the request with a receipt.
4. Server validates the receipt on-chain and returns 200 OK.

By leveraging the emerging x402 standard, we allow any agent equipped with our Python SDK to instantly interact with monetized endpoints. No accounts. No API keys. Just value exchanged for value.

Live on Devnet

You can see the on-chain receipt on our homepage right now. Every transaction is transparent and verifiable. We are preparing to flip the switch to mainnet soon.