To sell data to AI agents through x402, put a payment-aware server in front of a specific HTTP endpoint. The endpoint returns HTTP 402 with its payment requirements when a request arrives unpaid; a compatible agent can attach payment authorization and retry. Your server uses a facilitator to verify and settle the payment before delivering the data. You configure the route, price, receiving address, network and payment scheme, and facilitator. x402 is the protocol; a particular facilitator or business account is an implementation choice.
How does an AI agent pay for an API call?
The x402 flow uses HTTP 402, “Payment Required,” as a payment challenge. A client asks for a resource; if payment is required, the server responds with payment details rather than the data. A compatible agent can authorize payment and retry the request. The service verifies and settles the payment, commonly through a facilitator, and then returns the resource. This is the documented protocol flow, not a guarantee that every agent, wallet, network, or API client supports the same payment options. See the x402 whitepaper.
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- Request: The agent calls the data endpoint.
- Challenge: The server returns HTTP 402 and the requirements for paying that route.
- Authorization and retry: The agent supplies payment authorization and retries.
- Verification and delivery: The server or its facilitator verifies and settles payment, then serves the requested data.
What do I need to configure on the provider side?
At minimum, decide what endpoint is paid, how much it costs, where payment should go, which network and payment scheme the server accepts, and what facilitator verifies or settles payment. Coinbase’s maintained x402 server guide describes this pattern using its server packages and middleware.
- Choose a receiving address. Identify the address that should receive payment for the product.
- Select a network and scheme. Register the appropriate x402 scheme for the network you intend to support. Confirm current SDK support before deploying.
- Set up the server and facilitator. The guide shows a facilitator-backed resource server. It gives a public facilitator example and separately documents a CDP-authenticated route for production; check the current guide for package names, authentication, and supported networks.
- Price each protected route. Specify the amount and receiving address, plus a description and content type so the payment challenge describes what the buyer is requesting.
- Apply payment middleware before protected routes. Keep a health-check route outside the paid middleware if it should remain accessible without payment.
- Test the complete request cycle. Confirm that an unpaid request gets a 402 challenge, an authorized retry is handled as expected, and successful payment leads to the intended response.
The exact code and package names depend on the SDK version and language. The implementation guide is a starting point, not a substitute for checking current compatibility and deployment requirements.
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How should I price a paid data endpoint?
Coinbase’s implementation guide suggests these example ranges. They are vendor suggestions, not market averages, observed prices, or a universal pricing rule.
| Example category | Suggested price in Coinbase’s guide |
|---|---|
| Simple data lookup | $0.001–$0.01 |
| API proxy or enrichment | $0.01–$0.10 |
| Compute-heavy query | $0.10–$0.50 |
| AI inference | $0.05–$1.00 |
Choose a price based on the cost of producing and serving the data, its value to a buyer, the network and settlement arrangements, and what customers are willing to pay. A small price alone does not establish demand or make the economics work: account for infrastructure, data licensing, support, and any applicable transaction costs. Coinbase’s suggested ranges are in its implementation guide.
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How do I make a paid API discoverable to agents?
A reachable endpoint is not necessarily an understandable one. Describe what a paid request returns, the accepted inputs, output shape, data freshness, usage limits, and likely errors. Coinbase’s guide demonstrates adding discovery metadata such as a description and output example or schema, and says this can register a service with Bazaar. Coinbase’s documentation describes Bazaar as an MCP server with search and proxy-invocation tools; check its current Bazaar MCP documentation for live behavior and setup details.
Useful metadata helps an agent decide whether a result fits its task before it spends money. Treat discovery as a separate concern from payment: metadata can explain the product, while the HTTP payment challenge and server-side verification govern access.
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Is Coinbase required to accept USDC through x402?
No. The protocol’s payment flow and a vendor’s account product are distinct. Your facilitator, network, scheme, and receiving setup are implementation decisions; Coinbase’s guide documents Coinbase tooling, not a requirement that every x402 service use a Coinbase Business account.
Coinbase Business separately markets an account for receiving, managing, reconciling, and withdrawing agent payments. Its product page says it accepts USDC payments from wallets on Ethereum, Base, Polygon, Optimism, Avalanche, and Arbitrum, and describes use by businesses selling API access, digital products, or online services. Those are Coinbase product claims; confirm geographic availability, supported networks, terms, and current features directly with Coinbase Business before relying on them.
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What should I verify before launch?
- Compatibility: Verify that your agent or client, server SDK, facilitator, network, and payment scheme work together.
- Payment handling: Confirm how the facilitator is authenticated and what the server does when verification or settlement fails.
- Access and spending controls: Define which routes are paid, what each costs, and how clients can avoid unintentional repeated requests.
- Product clarity: Make response contents, freshness, inputs, limits, and errors explicit in the endpoint documentation and discovery metadata.
- Operations: Decide how you will monitor failed payments, endpoint errors, and delivery, and how you will reconcile receipts.
- Business terms: Check network and account availability, fees, and applicable product terms for your geography.
The available vendor documentation explains how to build the flow, but does not establish independent market-wide adoption, reliability, conversion, or revenue benchmarks. A Coinbase-published customer claim is not a substitute for independent evidence about likely demand for a particular data product.
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