To accept USDC from AI agents through x402, protect a data endpoint with payment middleware. An unpaid request receives HTTP 402 plus the payment requirements; the agent then retries with payment authorization, and the server verifies and settles the payment before returning the data. You configure the route, price, receiving address, network and payment scheme, and facilitator. The protocol does not require a particular payment-account provider.
How does an AI agent pay for an API call?
x402 uses HTTP’s 402 “Payment Required” status as a machine-readable payment challenge. In the flow described by the x402 whitepaper, a client requests a resource, receives a 402 response containing payment requirements, and retries with signed payment authorization. The service verifies and broadcasts or settles payment, then returns the requested resource. The exact verification and settlement arrangement depends on the implementation.
That means a paid data product can remain an HTTP endpoint rather than requiring a separate checkout page for each request. It does not mean every agent, wallet, network, or server is automatically compatible: the client and server still need to support compatible payment requirements and payment schemes.
What you configure on the provider side
Coinbase’s maintained x402 server implementation guide lays out a practical provider setup. Its example uses a facilitator-backed server; treat package names, authentication details, and network support as version-sensitive and confirm them against the current guide before deployment.
Recommended Free Tools
#1 Best Overall
- EAL5+ CERTIFIED SECURE ELEMENT + FINGERPRINT PROTECTION — Your private keys stay encrypted offline on a certified EAL5+ chip, the same security tier used in EMV bank cards. Built by DCENT, securing crypto since 2018. Fingerprint authentication adds a second layer no PIN-only wallet can match.
- 10,000+ ASSETS NATIVE ON 100+ BLOCKCHAINS — Hold Bitcoin, Ethereum, XRP, Solana, Cardano, popular stablecoins (USDT, USDC), and NFTs in one wallet. No third-party apps, no fragmented setup — every supported asset works straight out of the box.
- TAP-TO-SIGN MOBILE EXPERIENCE — Pair your wallet with the DCENT mobile app over Bluetooth. Manage tokens, review transactions, and access in-app swap features directly from your phone — no cables, no desktop required.
- WEB3 & dAPP ACCESS VIA METAMASK — Connect to MetaMask and other browser extension wallets to manage NFTs, claim airdrops, and access dApps. A large screen and intuitive 4-button interface keep every transaction clearly visible before you sign.
- SEAMLESS FIRMWARE UPDATES & 30-DAY MONEY-BACK GUARANTEE — Apply security updates without resetting your wallet or migrating funds. Backed by Amazon's 30-day money-back guarantee — your purchase is risk-free.
- Choose a receiving address. Decide where the endpoint’s payments should be directed and ensure the address is appropriate for the selected network.
- Choose a network and scheme. Select a supported USDC payment network and the corresponding x402 scheme. Register that scheme for the network in the server.
- Set up the server and facilitator. Install the server, network-scheme, and middleware packages shown in the current guide, then create the facilitator client and resource server. The guide shows a public facilitator example and separately documents an authenticated CDP facilitator route for production; those are implementation options, not protocol requirements.
- Price the protected route. For each paid route, set the price, pay-to address, a useful description, and the response content type.
- Add the middleware before the protected route. Requests should be challenged before the handler returns paid data. Keep a health-check route outside the paid middleware if it needs to remain freely accessible.
- Optionally add discovery metadata. Provide a description and output example or schema so an agent can judge whether the endpoint suits its task.
The guide’s example client wrapper detects a 402 response, attaches payment proof, retries, and receives the response. The x402 Agentic quickstart illustrates this with a Base Sepolia test route priced at $0.001. That is a documented test example, not a recommended production price or evidence of independent testing.
How should you price a data endpoint?
Coinbase’s implementation guide offers these suggested price ranges by workload. They are starting points from the guide, not market averages, observed transaction prices, or guarantees of what buyers will pay.
Rank #2
- EAL5+ CERTIFIED SECURE ELEMENT + FINGERPRINT PROTECTION — Your private keys stay encrypted offline on a certified EAL5+ chip, the same security tier used in EMV bank cards. Built by DCENT, securing crypto since 2018. Fingerprint authentication adds a second layer no PIN-only wallet can match.
- 10,000+ ASSETS NATIVE ON 100+ BLOCKCHAINS — Hold Bitcoin, Ethereum, XRP, Solana, Cardano, popular stablecoins (USDT, USDC), and NFTs in one wallet. No third-party apps, no fragmented setup — every supported asset works straight out of the box.
- TAP-TO-SIGN MOBILE EXPERIENCE — Pair your wallet with the DCENT mobile app over Bluetooth. Manage tokens, review transactions, and access in-app swap features directly from your phone — no cables, no desktop required.
- WEB3 & dAPP ACCESS VIA METAMASK — Connect to MetaMask and other browser extension wallets to manage NFTs, claim airdrops, and access dApps. A large screen and intuitive 4-button interface keep every transaction clearly visible before you sign.
- SEAMLESS FIRMWARE UPDATES & 30-DAY MONEY-BACK GUARANTEE — Apply security updates without resetting your wallet or migrating funds. Backed by Amazon's 30-day money-back guarantee — your purchase is risk-free.
| Workload 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 serving the request, the value and specificity of its output, network and facilitator choices, and what buyers will accept. No independent market benchmark or adoption statistic is established by the sources cited here, so these figures should not be read as proof of demand.
How do you make the paid API discoverable to agents?
A working endpoint is not necessarily an easy endpoint for an agent to evaluate. Describe what one paid request returns, the accepted inputs, the output format, data freshness, usage limits, and likely error responses. Include an output example or schema in the discovery metadata where supported; this advice follows the implementation guide’s metadata examples and is a product-design recommendation, not a protocol requirement.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Rank #3
- Compact and Convenient: Experience the power of security in the palm of your hand with a credit card-sized design that combines portability and convenience.
- Biometric Fingerprint Authentication: Elevate your security to new heights with advanced biometric fingerprint authentication. This cutting-edge technology adds an impenetrable layer, ensuring resilience against unauthorized access. Your assets are safeguarded like never before.
- Encrypted Bluetooth Connection: Stay connected with confidence through an encrypted Bluetooth connection, providing a secure link between your hardware wallet and your devices.
- Ultimate Security Certification: Rest easy knowing your assets are protected by the highest standards. SecuX Shield is certified CC EAL5+, featuring the Infineon Solid Flash CC EAL5+ Secure Element (SE) chip embedded for ultimate security.
- Hands-on Clear-sign: Take control with a clear-view display of transaction details. Hands-on device authorization ensures a seamless and transparent user experience.
The guide describes registering services with x402 Bazaar. Coinbase’s Bazaar MCP documentation is described as providing resource search and proxy-invocation tools, but its current documentation path and catalog behavior should be confirmed before relying on them. Discovery support is separate from the basic payment challenge: an endpoint can use x402 without assuming that a particular catalog will list it.
Is Coinbase Business required to receive USDC?
No. x402 payment mechanics and a vendor’s account or reconciliation product are separate choices. Coinbase Business markets an optional 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, or Arbitrum and is aimed at businesses selling API access, digital products, or online services. Those are Coinbase product claims; supported geographies, current availability, and terms should be checked on its agentic payments page. A provider can evaluate that product independently of whether it uses a Coinbase facilitator.
Rank #4
- Securely backup seed phrase of your bitcoin & cryptocurrency hardware and software wallets, (compatible with Ledger, Trezor, Trust Wallet, Bitbox, KeepKey, MetaMask, Coinbase Wallet, Mycelium, Exodus, Wasabi Wallet, Keystone, Onekey...)
- Made of 304-grade indestructible stainless steel, fireproof, waterproof, anti-corrosion, and anti-destruction, your seed words are always protected and Internet isolated.
- Compatible with all BIP39 hardware and software wallets, supports 12, 18, 24 mnemonic seed phrase (only first 4 letters needed). A total of 288 letters are provided. Support unlimited cryptocurrencies (Bitcoin, Ethereum, Polygon, Ripple, Shiba, Litecoin, Dogecoin, Cardano, Binance, Avalanche, Solana, USDC, USDT ...)
- 100% Offline, no WIFI, no bluetooth, the safest way to store mnemonic seed phrase, never have to worry about being hacked.
- Very convenient to use, anyone can install it easily to store seed phrase safely. It also can be locked with the hole in the product.
What to compare before choosing an implementation
There is no established winner among implementation approaches in the cited material. Compare the practical operating requirements before committing:
Quick Recap
Best Value
- Ultimate Security: Certified CC EAL5+. Infineon Solid Flash CC EAL5+ Secure Element (SE) chip embedded
- Offline and Unhackable: Store your private key offline away from hacking threats and phishing attacks.
- Hands-on Clear-sign: Clear-view display of transaction details. Hands-on device authorization
- PIN protected: Dynamic keypad for PIN entry. Automatic reset after 5 unsuccessful PIN entries
- Intuitive Color Touchscreen: 2.8 inch large touch screen allows secure, easy and instant verification
- USDC network and payment-scheme support for both your clients and server.
- Facilitator availability, authentication, verification and settlement behavior.
- SDK and middleware compatibility with your language and framework.
- Receiving-address operations, fees, observability, and security or spending controls.
- Discovery features and whether the current catalog behavior fits your product.
- Geographic availability and terms for any optional payment-account product.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
