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In a nutshell
AI agents can pay for APIs and data per request, in stablecoins, through open agent payment protocols. If you sell to agents, a Blockradar address can receive those payments. They arrive as ordinary deposits, with the usual webhook and the paying agent’s wallet as the sender, so there is nothing new to integrate on the Blockradar side.

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Supported Protocols

Building the agent that pays? See Make Agent Payments.

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Prerequisites

1

API Key

Get your API key from the Blockradar Dashboard. Navigate to Developers to generate one.
2

EVM Master Wallet

Create a master wallet in the dashboard on the chain you charge on, such as Base (see Create a Master Wallet).
3

USDC Enabled

Enable USDC on the wallet. Your wallet only detects deposits for assets you have added. See Asset Management.
4

Webhook URL

Configure a webhook endpoint in your dashboard under Developers → Webhooks to be notified of each payment.

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How x402 Works

x402 is an open protocol that lets an API charge per request. Your API answers an unpaid request with HTTP 402 Payment Required and the price, the agent retries with a signed USDC authorization, and a facilitator verifies that authorization and submits the transfer on-chain, paying the gas. The USDC moves straight from the agent’s wallet to your payTo address. You run the x402 server middleware and choose the facilitator. Blockradar is where the money lands.

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Get Paid with x402

1

Set a Blockradar address as payTo

Use the master wallet’s address, or generate a child address per product or customer and attach metadata so each payment maps back to what was bought. On the Checkout plan, child addresses are not available, so use the master wallet’s address.
2

Settle through a facilitator

Point your x402 middleware at a facilitator that supports your network. Circle’s Facilitator Service settles USDC on Arc, Base, and Polygon PoS. Use a Circle API key when configuring it.
3

Receive the payment as a deposit

When the facilitator settles, the USDC transfer to your payTo address is detected like any other deposit and fires the usual deposit.success webhook.
In the webhook, senderAddress is the buyer’s wallet, not the facilitator that submitted the transaction, so you can see who paid. hash matches the transaction in the PAYMENT-RESPONSE your server returned.
x402 payments are often a cent or less. If payTo is a child address with auto-sweep on, each payment is swept to the master wallet separately. Set a sweep threshold on USDC, or use the master wallet’s address as payTo, so you are not paying to sweep amounts smaller than the sweep fee.

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x402 Limitations

  • EVM networks. Payments on non-EVM x402 networks, such as Solana, have not been tested with Blockradar addresses.
  • No Circle Gateway nanopayments. Circle’s batched sub-cent payment option has not been tested with Blockradar wallets.

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Best Practices

  • One address per product or customer. Generate a child address per paid resource or per buyer account and tag it with metadata, so every deposit webhook tells you what was bought without a lookup.
  • Reconcile by hash. Match each deposit.success webhook’s hash to the transaction your server returned in PAYMENT-RESPONSE.
  • Test on testnet first. Point your middleware at a testnet network, such as Base Sepolia (eip155:84532), and pay yourself with testnet USDC from the faucets before going live.

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API Reference