Agent payments overview
Every Swop product can be bought by an AI agent, paid in USDC on Base over the x402 protocol. Nothing to set up.
AI agents increasingly shop on someone's behalf: a research assistant buying a report, a coding agent paying for an API call, a personal assistant ordering a gift. They don't fill in checkout forms. They make an HTTP request, get told the price, pay, and get the thing.
Swop makes every product you sell payable that way, automatically.
The 30-second version
- You add a product to your Swop page (in the app, with the Swop MCP, or through the Payments API).
- That product now has a buy URL. A person who opens it sees a product page. An agent that requests it gets an HTTP 402 Payment Required response that states the exact price in USDC and where to send it.
- The agent signs a USDC payment and sends the same request again with the signature attached.
- Swop verifies and settles the payment on-chain, records the order, and returns a receipt with the transaction hash.
The seller is paid in USDC on Base, straight to their wallet. There's no merchant verification on this rail and no separate onboarding.
New to this?
x402 is an open standard that gives the web's long-unused status code, 402 Payment Required, a real job: a server answers "this costs $5, pay here", and a client pays and retries. USDC is a digital dollar issued by Circle; 1 USDC is designed to be worth 1 US dollar. Base is the blockchain the payment settles on. You don't need to run any of this yourself to sell: Swop does it for every product.
What you can do
How it works
The request, the 402 challenge, the signed payment and the receipt, step by step.
Sell to agents
What happens when you list a product, and what agents can see.
Store listing
The public JSON catalogue agents read to find your products.
Pay from an agent
Build an agent that buys from any Swop seller, with working code.
Facilitator & networks
Protocol versions, headers, networks, assets and limits.
Status
| Piece | Status |
|---|---|
| Every product payable by agents (USDC on Base, x402 v2 with v1 accepted) | Live since September 2026 |
Store listing at /api/v5/x402/store/<swop.id> | Live |
| Discovery in Coinbase's x402 Bazaar after a first paid sale | Live |
Swop users' own AIs paying x402 links (swop_pay_x402_link) | Live, through the Swop MCP |
| Swop running its own facilitator | Planned |
Fees
At launch, agent payments carry no Swop platform fee: the full price in the 402 goes to the seller's wallet (or to escrow for physical goods). Card and checkout payments have their own fee, described in Payments.