How AI Agents Pay

When an AI agent buys something for you, four problems have to be solved at once: the payment credential has to reach the merchant without being exposed, the merchant has to know you actually authorized this purchase, the right party has to be on the hook if something goes wrong, and all of it has to happen without a human clicking “buy.” This page explains the mechanisms, then the specific products built on them. For how a full agent purchase flows from discovery to settlement, start with what is agentic commerce.

The four mechanisms

Tokenization is the foundation. Instead of handing an agent a real card number, the networks and processors issue a token bound to a specific authorized agent and to the limits you set. Stripe’s Shared Payment Token is the processor-side version: a single-use credential scoped to one merchant and one cart total.

Mandates, or verifiable credentials, are the trust layer. This is the core of Google’s AP2: cryptographically signed, tamper-evident records of what you authorized, which a merchant or bank can verify and later use as dispute evidence.

Passkeys and delegated authority are how your approval is captured. Mastercard ties its agent tokens to payment passkeys and on-device biometrics; AP2 uses hardware-backed device keys; the Stripe and OpenAI model asks you to confirm each step explicitly. The common thread is strong, device-bound proof that the human, not just the agent, signed off.

Liability handling is the least settled of the four, and the products differ most here.

The network and processor products

Visa Intelligent Commerce opened Visa’s network to AI agents, announced on 30 April 2025. It centers on “AI-Ready Cards,” which replace card details with tokenized credentials that confirm a chosen agent is authorized to act for the consumer, with spending limits and conditions the consumer sets. Launch collaborators named by Visa included Anthropic, IBM, Microsoft, Mistral AI, OpenAI, Perplexity, Samsung, and Stripe. By a December 2025 update, Visa described hundreds of agent-initiated transactions and a growing partner roster, but the program was still in closed beta and pilot, not general availability. On 8 April 2026 Visa added Intelligent Commerce Connect, a network, protocol, and token-vault-agnostic “on ramp” that lets merchants accept agent-initiated payments through a single Visa Acceptance Platform integration, working across major agent protocols including the Trusted Agent Protocol, the Machine Payments Protocol, ACP, and UCP. Note that AP2 is not among the protocols Visa names. Visa launched it in pilot with partners including Aldar, AWS, Diddo, Highnote, Mesh, Payabli, and Sumvin. Visa’s own announcement said only that it would reach more partners during the year; trade reporting at the time pointed to general availability around the end of June 2026, but as of October 2026 Visa has not published a first-party confirmation that Connect has reached general availability, so treat it as still rolling out. Visa also led a separate effort, the Trusted Agent Protocol, to help merchants tell legitimate agents from bots. On 20 October 2026 Visa, BILL and Billtrust announced what they called the first live pilot of trusted AI agent payments between buyer and supplier platforms, in which an agent registered and authenticated through the Trusted Agent Protocol pays already-approved invoices through supplier portals using tokenized credentials.

Mastercard Agent Pay was announced a day earlier, on 29 April 2025. It uses Mastercard Agentic Tokens, built on the same tokenization behind contactless and Mastercard Payment Passkeys, and requires agents to be registered and verified before they can pay, with consumers setting controls over what an agent may buy. Named partners included Microsoft, IBM, Braintree, and Checkout.com. For machine-to-machine payments, Mastercard’s Agent Pay for Machines builds on x402; on 20 October 2026, after pilots with Cloudflare, Coinbase, Ant International and others, Mastercard made the first version of its buyer- and seller-side APIs available to developers in early access.

American Express entered later, on 14 April 2026, with two things together: an Agentic Commerce Experiences (ACE) developer kit and Amex Agent Purchase Protection, which Amex describes as an industry-first commitment to protect card members from charges resulting from registered AI agent error. That pledge is the most concrete liability stance any network has made, though note its scope: agent error on Amex’s own closed-loop network, not a general chargeback framework. On 6 October 2026 Amex restated it as an intent to protect eligible Card Members and Merchants, but full terms are still unpublished, so treat it as announced rather than live. On 13 October 2026 Amex published Intent Intelligence, a core ACE service that captures and authenticates a customer’s purchase intent before an agent transacts and issues a Proof of Intent Token that can be used to obtain a payment credential instead of the card number. The developer kit went to select partners first, so this is early-stage rather than broadly available.

PayPal plays a dual role: it is an AP2 launch partner, announced on 16 September 2025, and it offers an agent toolkit and remote MCP server so businesses can build agentic experiences on PayPal’s APIs. Its AP2 work maps the protocol’s mandates, expressed as W3C verifiable credentials, onto PayPal’s wallet, checkout, and dispute workflows, though much of it is framed as architecture and intent rather than shipped features.

Stripe co-developed the Agentic Commerce Protocol with OpenAI and powers Instant Checkout in ChatGPT, which is the single most concretely live consumer-facing agentic payment flow in this list. Its mechanism is the Shared Payment Token described above, launched on 29 September 2025 for US buyers.

Stablecoins and the machine-to-machine rail

For payments between software rather than consumer checkout, the leading approach is x402, an open protocol from Coinbase that revives the dormant HTTP “402 Payment Required” status code to let software settle in stablecoins such as USDC directly over the web, with no accounts or card credentials. A buyer requests a resource, the server responds with payment instructions, the buyer returns a signed payment, and a facilitator verifies and settles the transaction on-chain. In September 2025, Coinbase and Cloudflare announced an x402 Foundation to steward it as a neutral standard, and Google aligned it with AP2 through the A2A x402 extension.

That foundation is no longer just an announcement. On 14 July 2026 the Linux Foundation launched the x402 Foundation operationally, with Coinbase’s contribution of the protocol complete and 40 member organizations at launch; its members page listed 57 by late October 2026. Its premier members, who hold governing-board seats, include Visa, Mastercard, American Express, PayPal, Stripe, Google, Adyen, AWS, Shopify, Circle, Cloudflare, Coinbase, Fiserv, and Ripple. That membership list is the clearest signal available that the card networks and processors are hedging across rails rather than backing a single standard. x402 is live infrastructure, but it is aimed at agent-to-agent and micro-transaction use cases, not retail checkout.

A second machine-native standard arrived in March 2026: the Machine Payments Protocol (MPP), an open protocol co-authored by Stripe and Tempo for agents to pay services programmatically, for things like microtransactions, recurring payments, and paying per API call. An agent requests a resource from a service, API, or MCP endpoint, the service returns a payment request, the agent authorizes it, and the resource is delivered. Stripe lets businesses accept MPP payments through its existing PaymentIntents API, in stablecoins as well as the cards, wallets, and other methods carried by Shared Payment Tokens, so the funds settle into a normal Stripe balance. Like x402, MPP targets the software-to-software lane rather than consumer retail checkout, and Stripe supports both.

Announced versus live

The honest summary is that there is far more announced than live. The genuinely live consumer flow is Stripe and OpenAI’s Instant Checkout, and even that started US-only and limited. Visa’s and Mastercard’s programs are pilots and closed betas. American Express’s developer kit reached select partners in April 2026. Across the industry, there have arguably been about as many announcements as real transactions. x402 and MPP are real and running, but in a different lane.

Liability deserves a final word because it is what merchants and consumers will care about most. Only American Express has made a concrete pledge, and it covers charges resulting from registered agent error on its own network. AP2 is often described as assigning accountability, and it does not: its own materials pose accountability as an unanswered question, name its objective as providing “supporting evidence that helps payment networks establish accountability and liability principles,” and, while specifying dispute evidence and mandatory verification rules, leave the use of that evidence for dispute resolution, and retention and retrieval, outside the specification. Signed mandates and receipts are evidence for someone else’s rulebook. No finalized, cross-network rulebook for disputing an agent-initiated purchase exists yet, and that gap, more than any technical one, is what still has to close. For the companies behind these products and how they fit across the stack, see the agentic commerce landscape.