Mastercard opened developer APIs, SDKs and a sandbox for Agent Pay for Machines (AP4M) on October 21, 2026. The tools enable autonomous AI agents on Amazon Bedrock to make multi-merchant micropayments over x402 using off-chain signed vouchers. The launch follows Coinbase Developer Platform’s report that cumulative x402 payments across Base and Solana had exceeded 100 million by October. The x402 protocol uses an HTTP 402 response to tell an agent what a service costs and how to pay. Its growing infrastructure includes a Linux Foundation-governed foundation, while alternative approaches use Lightning payments or existing processor rails. Transaction counts, however, do not establish how much genuine agent-led commerce is taking place. TRM Labs found a much smaller pool of plausible commercial trade after screening out other activity. Security questions also remain, including whether a service can receive payment without delivering its output. Developers therefore face choices about settlement, spending controls and proof of service.

Coinbase demonstrated machine-to-machine AI payment workflows at Sibos 2026 in Miami Beach, highlighting the Model Context Protocol, Agent-to-Agent protocol and its x402 payment standard. The demonstration followed the August general availability of Amazon Bedrock AgentCore Payments, which incorporates Coinbase Developer Platform wallet infrastructure and x402 settlement. The AWS service supports Coinbase Developer Platform and Stripe Privy wallets for autonomous USDC microtransactions, while keeping developer credentials separate from AI agents and applying deterministic spending limits. The work connects a conference demonstration to infrastructure already available to developers. Coinbase and AWS had also enabled publishers and API endpoints using AWS CloudFront and AWS WAF to monetize autonomous agent traffic through x402. Coinbase Institute research argues that AI agents need sub-cent stablecoin payments, although that argument is not evidence of transaction volumes. The developments show how payment authorization, wallet access and settlement are being assembled for agent-initiated transactions, without establishing how widely the technology is used.