D20DAO now documents an HTTP API that lets agents buy verifiable random results for 0.05 USDC per call without deploying their own consumer contract. Payments use x402 through Circle Gateway; the underlying randomness request runs on Arc Mainnet.
The API supports dice, selections and shuffles as well as a raw random word. That gives an agent a way to purchase a discrete service for a game or sampling task, instead of requiring its operator to build a smart-contract integration first.
An unpaid request to the live endpoint on September 19 returned HTTP 402 with x402 version 2 requirements and 12 payment-network options, including Base, Ethereum and Arc. Each specified 50,000 units of six-decimal USDC, equivalent to 0.05 USDC. This check confirmed the payment offer; it did not execute a paid draw or independently verify settlement.
Payment and result are separate records
The specification distinguishes a completed result from a pending response. Clients can retrieve payment status for free and should retain the payment and request identifiers. D20DAO says resubmitting the same payment returns the same result. Its refund policy covers settled calls that fail to deliver, with some cases requiring manual review; it excludes the caller's network and Gateway costs.
API3's AirnodeHub supplies a separate part of D20DAO's existing workflow: signed API inputs selected under the randomness protocol's source rules. x402 pays for access to the service. It does not replace the VRF proof or establish the accuracy of every input.
For developers, the change is a smaller integration boundary: an HTTP client can pay for a result and receive identifiers for checking its onchain record. Applications still need their own rules for using that result and settling any prize or other obligation.
Sources: D20DAO agent guide, API specification, refund policy, source-input rules.
Related reading: Arc's zero PREVRANDAO makes randomness a separate infrastructure choice; What a verifiably random game proves, and what players still need to check.