Visa, Mastercard, Stripe, and Google Are Racing to Give AI Agents Your Credit Card

The biggest financial infrastructure war of the decade is not about who has the best model. It is about who gets to process the transaction when your AI agent buys something without asking you first.

In the past four months, Visa, Mastercard, Stripe (alongside OpenAI), and Google have each launched competing protocols designed to let AI agents initiate, authorize, and complete purchases on behalf of humans. Real money has already changed hands. DBS Bank in Singapore ran the first authenticated agent-initiated food purchases in Asia Pacific. Mastercard processed its first agentic transaction on-network last quarter. OpenAI's ChatGPT now lets users buy from Etsy sellers without leaving the chat.

McKinsey projects this market at $3 trillion to $5 trillion globally by 2030. The question is not whether AI agents will spend your money. It is which company controls the rails.

The Four Protocols

The approaches split into two camps. Visa and Mastercard are extending their existing card networks, adding identity and authorization layers on top of infrastructure that already processes trillions in annual volume. Stripe and Google are building new protocols from scratch, betting that the agentic economy needs purpose-built rails rather than retrofitted ones.

Visa: The incumbent play

Visa Intelligent Commerce wraps agent identity verification around existing payment flows. The Trusted Agent Protocol adds what amounts to a digital passport for AI bots, letting merchants verify that the agent making a purchase is authorized by the cardholder's bank. Over 100 partners are onboarded globally, with 20-plus agent platforms integrating directly. Pilots in Asia Pacific, Europe, and Latin America launched in early 2026.

Visa's advantage is reach. It already sits between virtually every consumer and every merchant. The bet is that merchants will not adopt a new protocol when they can add agent support to the Visa integration they already have.

Mastercard: Move fast, partner widely

Mastercard's Agent Pay uses Agentic Tokens, dynamic credentials that change per transaction and carry embedded spending rules. The system rolled out to all US cardholders by November 2025, with Citi and US Bank among the first issuers enabled. In February 2026, Mastercard completed Australia's first authenticated agentic transactions.

"The train is leaving the station, and we're right in the front of it," Mastercard CEO Michael Miebach said during the company's earnings call. "Only when there is trust will this whole space actually evolve."

Mastercard is also hedging its bets by participating in Google's protocol and OpenAI's protocol simultaneously, ensuring it sits at the intersection of whatever standard wins.

Stripe and OpenAI: The developer bet

The Agentic Commerce Protocol is an open-source specification co-developed by Stripe and OpenAI. It introduces Shared Payment Tokens for single-transaction authorization and can be implemented as either a REST API or an MCP server. The protocol already powers Instant Checkout inside ChatGPT, where US users can buy from Etsy and soon from over a million Shopify merchants.

The Stripe approach is pragmatic. It packages the new protocol with Stripe's existing merchant infrastructure, meaning any Stripe-connected business can add agentic commerce support with minimal integration work. The limitation is exactly that: it only works with Stripe-connected merchants.

Major retailers are already onboard. URBN (Anthropologie, Free People, Urban Outfitters), Coach, Kate Spade, Revolve, and Ashley Furniture have joined the Agentic Commerce Suite. At NRF 2026 in January, 75% of attendees reported they were either implementing or actively planning agentic commerce initiatives.

Google: The open-standard gambit

Google's Agent Payments Protocol launched with over 60 supporting companies, and the underlying A2A Protocol has been donated to the Linux Foundation with 150-plus organizational backers. AP2 uses "mandates," cryptographically-signed digital contracts that serve as verifiable proof of a user's instructions.

The protocol is deliberately payment-agnostic. It works with credit cards, debit cards, real-time bank transfers, and cryptocurrencies. Google also launched the Universal Commerce Protocol at NRF 2026 in partnership with Shopify, Etsy, Wayfair, Target, and Walmart, establishing standardized interfaces for AI agents to discover products across retail platforms.

Counter-Argument

The industry excitement is running well ahead of consumer readiness.

Only 24% of US consumers say they would be comfortable letting an AI agent make a purchase today. While 52% are willing to share data with AI shopping agents, 83% express concerns about privacy, data misuse, and unwanted marketing. That is an extraordinary trust gap for an industry projecting trillions in volume within four years.

There is also a fraud problem that nobody has solved. AI agents transacting at odd hours, across geographies, with rapid repeated purchases look exactly like fraud bots to existing detection systems. Visa's own threat analysis acknowledges that fraudsters are already manipulating agentic shopping results to steer consumers toward scam merchants, and that AI shopping agents can be deceived by "sophisticated counterfeit merchants engineered specifically to exploit them."

The security architecture is being built in real time, which means the first wave of autonomous agents spending real money will be operating on infrastructure that has not been stress-tested at scale. When Mastercard's Miebach says trust is the prerequisite, he is also describing the industry's biggest unsolved problem.

The protocol fragmentation risk

Four competing protocols from four of the world's most powerful technology companies is not interoperability. It is a standards war. Merchants who integrate with Visa's VIC gain no compatibility with Stripe's ACP. A retailer supporting Google's AP2 still needs separate work for Mastercard's Agent Pay. The Universal Commerce Protocol endorsed by Google is also endorsed by Visa, Mastercard, and Stripe, but UCP handles product discovery, not payment authorization, which is where the real competition lies.

The historical pattern is clear. Standards wars in payments, as we saw with NFC, mobile wallets, and QR codes, take years to consolidate. Meanwhile, merchants pay integration costs for every protocol they support, and those costs get passed to consumers.

What the Market Is Missing

Every company in this race is framing agentic commerce as a consumer convenience story. AI agents will save you time. They will find better deals. They will handle the tedious parts of shopping so you do not have to.

But follow the money. Visa and Mastercard charge interchange fees on every transaction. Stripe takes a percentage of every payment it processes. Google's commerce protocols funnel purchasing through surfaces where it sells advertising. OpenAI's Instant Checkout is a monetization channel for a company that just launched ads in ChatGPT and projects $1 billion in free-user revenue this year.

The entity that controls how AI agents pay is not just processing transactions. It is capturing the most valuable data stream in commerce: real-time purchase intent, derived from the full context of a conversation between a human and an AI. That is worth more than interchange. It is worth more than advertising. It is the complete picture of what you want, when you want it, and how much you are willing to pay, delivered in a format that machines can act on instantly.

McKinsey's $5 trillion figure is not a projection of consumer savings. It is a projection of orchestrated revenue, money that flows through systems controlled by a handful of companies that have positioned themselves between every buyer and every seller. The question is not whether agentic commerce will arrive. It is whether anyone is building the infrastructure to ensure it works for the people spending the money, and not just the companies moving it.

Sources:

• The AI Agent Payments Landscape in 2026 - Proxy
• Visa and Partners Complete Secure AI Transactions - Visa
• Mastercard accelerates AI-powered commerce with Australia's first authenticated agentic transactions - Mastercard
• Stripe powers Instant Checkout in ChatGPT and releases Agentic Commerce Protocol - Stripe
• Announcing Agent Payments Protocol (AP2) - Google Cloud
• DBS is first bank in Asia Pacific to pilot Visa Intelligent Commerce - DBS
• McKinsey: The agentic commerce opportunity - McKinsey
• The three biggest agentic commerce trends from NRF 2026 - Stripe
• Visa, Mastercard race to agentic AI commerce - Payments Dive
• Mastercard Leans Into Agentic Commerce and Stablecoins - PYMNTS