Mastercard opens its AI-agent payment rails to developers after pilots with Coinbase and Cloudflare, with stablecoin settlement on Base

Mastercard wants software to pay its own bills. On Tuesday it opened early access to Agent Pay for Machines, a machine-to-machine payment system first announced in June, giving developers its first buyer-side and seller-side APIs, a toolkit and a sandbox, The Block and Decrypt reported. The project is still a pilot and not yet commercially available, The Block reported, and Mastercard asked developers to test the APIs and say what they want added. "That's what we're building," the company said in a statement to The Block.

The plumbing is crypto-native. Agent Pay for Machines runs on x402, an open protocol that The Block describes as incubated by Coinbase, named after the HTTP status code "402 Payment Required." When a paid service returns that code, the agent replies with a signed payment voucher, a promise to pay within the limit its owner set; the seller verifies the voucher before delivering, and vouchers can be batched and redeemed later rather than settled one by one, per both outlets.

The demo showed how it fits together. At Cloudflare's Connect conference, an agent working for the marketing agency Hype was told to prepare a campaign for a protein bar launch within an approved budget. It bought social media research from one provider and eight campaign images through Cloudflare's AI Gateway, making nine payments in all, per The Block. The agent's funded wallet came from Coinbase Developer Platform, Base handled on-chain settlement, and BVNK, the stablecoin infrastructure provider Mastercard bought in August, acted as the agent's wallet and handled payment and settlement in fiat or stablecoins through Mastercard's Global Money Platform. Pilot partners also included Ant International. It follows the Stablecoin Security risk tool Mastercard recently launched, Decrypt noted.