SELLING TO AI: THE COMPLETE GUIDE TO AGENTIC COMMERCE

For 30 years, checkout has been a page. A form with fields for name, address, credit card number. Whether it was Amazon's one-click patent or Apple Pay's fingerprint, the innovation was always about making that form faster to get through.

The form itself never went away. Now it is.

This is the final article in a five-part series on optimizing websites for the agentic web. Part 1 covered the evolution from SEO to AAIO. Part 2 explained how to get your content cited in AI responses. Part 3 mapped the protocols forming the infrastructure layer. Part 4 got technical with how AI agents perceive your website. This article covers the commerce layer: how AI agents find products, complete purchases, and handle payments without ever loading a checkout page.

In September 2025, Stripe and OpenAI launched Instant Checkout inside ChatGPT. In January 2026, Google and Shopify unveiled the Universal Commerce Protocol at the National Retail Federation conference. Two open standards. Two competing visions for the same shift: checkout becoming a protocol, not a page.

Throughout this article, we draw exclusively from official documentation, research papers, and announcements from the companies building this infrastructure.

In This Series

1. From SEO and CRO to 'AAIO': Why Your Website Needs to Speak to Machines
2. Answer Engine Optimization: How to Get Your Content Into AI Responses
3. MCP, A2A, NLWeb, and AGENTS.md: The Standards Powering the Agentic Web
4. How AI Agents See Your Website (And How to Build for Them)
5. Selling to AI: The Complete Guide to Agentic Commerce (You are here)

Contents

• How We Got Here
• Checkout Is No Longer a Page
• The Agentic Commerce Protocol
• The Universal Commerce Protocol
• The Trust Problem: Payments Without People
• Who's Already Selling to AI
• The Market
• How to Get Started
• Key Takeaways

How We Got Here

Every generation of commerce technology has solved the same problem: reducing the friction between "I want something" and "I have it." Agentic commerce is not a break from this pattern. It's the pattern's logical conclusion.

1994: The first online purchase. On August 11, 1994, Phil Brandenberger used his credit card to buy Sting's Ten Summoner's Tales CD for $12.48 from a website called NetMarket. The New York Times covered it the next day. NetMarket's 21-year-old CEO, Daniel Kohn, told the paper: "Even if the N.S.A. was listening in, they couldn't get his credit card number." Netscape's SSL protocol, released that same year, made it possible.

The friction removed: you no longer had to go to a physical store.

Late 1990s: Comparison shopping. Within a few years, websites like BizRate (1996), mySimon (1998), and PriceGrabber (1999) let buyers see prices across multiple merchants instantly. Google entered the space in 2002 with Froogle, later renamed Google Product Search in 2007, then Google Shopping in 2012.

The friction removed: you no longer had to visit each store to compare.

1998: The store adapts to you. Amazon deployed item-to-item collaborative filtering at scale, the algorithm behind "customers who bought this also bought." Greg Linden, Brent Smith, and Jeremy York published the underlying research in IEEE Internet Computing in 2003. In 2017, the journal named it the best paper in its 20-year history.

The friction removed: you no longer had to know exactly what you wanted.

2015: Commerce moves into conversations. Chris Messina, then Developer Experience Lead at Uber, coined the term "conversational commerce" in a January 2015 Medium post, describing "delivering convenience, personalization, and decision support while people are on the go." In April 2016, Mark Zuckerberg launched the Facebook Messenger Platform, declaring: "I've never met anyone who likes calling a business." Meanwhile, in China, WeChat had already proved the model. Its Mini Programs, launched January 2017, generated 800 billion yuan (~$115 billion) in transactions by 2019.

The friction removed: you no longer had to open a store's website.

2014-2023: Voice and social commerce. Amazon Echo launched in November 2014, promising you could buy things without a screen. The promise was mostly unfulfilled. Social commerce had better luck: TikTok Shop, launched in the US in September 2023, reached $33.2 billion in global sales by 2024. Content became the storefront.

The friction removed: purchase intent was created inside the feed, not searched for.

2024: AI starts shopping for you. Within months, every major platform launched AI shopping features. Amazon introduced Rufus in February, a conversational assistant trained on its product catalog. Google rebuilt Shopping with AI in October, drawing on 50 billion product listings. Perplexity launched "Buy with Pro" in November, turning a search engine into a store.

The friction removed: AI did the research, comparison, and recommendation for you.

2025: The buyer disappears. In January, OpenAI launched Operator, an agent that navigated websites, filled forms, and completed purchases autonomously. In May, Google announced "Buy for Me" at I/O 2025. In September, Instant Checkout went live in ChatGPT.

The friction removed: the last one. The human no longer needs to be there for the transaction to happen.

Each of these shifts was about the same thing: removing one more step between wanting and having. Agentic commerce removes the final step: doing it yourself.

Checkout Is No Longer a Page

Here's the shift in one sentence: in traditional commerce, the seller builds the checkout experience. In agentic commerce, the agent does.

When you buy something on a website today, you interact with the merchant's checkout page. They designed the form, they chose the layout, they control the flow. You fill in your details, click "Buy," and the payment processes.

In agentic commerce, the AI agent presents the checkout information within its own interface. ChatGPT shows you the product, the price, the shipping options, within the chat. You confirm. The agent handles the rest. The merchant never renders a page. They receive an API call.

Stripe's agentic commerce guide puts it directly: "The parts of commerce that used to be user experience problems are becoming protocol problems." Instead of optimizing button colors and form layouts, merchants are defining API endpoints and product feeds. Discovery, comparison, and checkout are all handled by the agent. The merchant's job shifts to supplying structured product data and processing the order.

Emily Glassberg Sands, Stripe's Head of Information and Data Science, framed the broader implications: "Agents don't just change who's at the checkout. They change who's doing the searching, the deciding, the trusting. All of it."

I discussed this with Jes Scholz, who ran digital across 140+ e-commerce brands at Ringier, on the podcast. Her experience was clear: agents browse in text mode, and if they can't parse your site cleanly, they leave. No second chances.

This isn't theoretical. As of February 2026, several agentic commerce implementations are live. ChatGPT Instant Checkout is available to US users on Free, Plus, and Pro plans. Etsy, Instacart, and Walmart are among the merchants processing orders through it. Shopify's Agentic Storefronts are active by default for eligible merchants, syndicating products to ChatGPT, Google AI Mode, Microsoft Copilot, and Perplexity simultaneously. Perplexity launched Instant Buy with PayPal in November 2025, allowing purchases directly within the chat interface with merchants like Wayfair, Abercrombie & Fitch, and thousands more via BigCommerce and Wix.

Every major AI company is moving in this direction. Anthropic, the company behind Claude, has been equally explicit about its commerce plans. In February 2026, Anthropic confirmed it is building features for "agentic commerce, where Claude acts on a user's behalf to handle a purchase or booking end to end," while committing to keeping the experience ad-free with no sponsored links or third-party product placements. Claude already connects to Stripe, PayPal, and Square via MCP integrations. And in June 2025, Anthropic published Project Vend, a research experiment where Claude autonomously operated a physical retail store for a month, managing inventory, pricing, supplier relations, and customer interactions. The results were instructive: the agent performed well at supplier discovery and customer service, but sold items at a loss and hallucinated payment details. A useful preview of both the potential and the current limitations.

Two open protocols are making this possible. Both launched within four months of each other.

The Agentic Commerce Protocol

The Agentic Commerce Protocol (ACP) is an open standard co-developed by OpenAI and Stripe, announced September 29, 2025. Licensed under Apache 2.0, it defines how AI agents complete purchases on behalf of users.

ACP uses a four-party model: the buyer (discovers and approves), the AI agent (presents products and handles checkout UI), the merchant (processes the order and payment), and the payment service provider (handles payment credentials securely). The merchant remains the merchant of record. They process the payment, handle fulfillment, manage returns. The agent is an intermediary, not a marketplace.

The protocol defines four API endpoints:

The responsibility shift is worth spelling out:

The agent handles what the buyer sees. The seller handles what happens after they click "Buy." ACP can be implemented as either a REST API or an MCP server, connecting naturally to the protocol ecosystem covered in Part 3.

Stripe's Agentic Commerce Suite, launched December 11, 2025, makes ACP adoption practical. Ahmed Gharib, Stripe's Product Lead for Agentic Commerce, described it as "a low-code solution enabling businesses to sell across multiple AI agents via a single integration." Without it, connecting to each AI agent individually would take up to six months of bespoke engineering per platform.

The Suite has three components: product discovery (sync your catalog and Stripe distributes it to AI agents), checkout (powered by Stripe's Checkout Sessions API, handling taxes and shipping), and payments (using Shared Payment Tokens and Stripe Radar for fraud detection). Merchants connect their existing product catalog or upload directly to Stripe, then select which AI agents to sell through from the Stripe Dashboard.

The ecosystem is growing quickly. Beyond OpenAI, Stripe lists Microsoft Copilot, Anthropic, Perplexity, Vercel, and Replit as AI platform partners. On the e-commerce side, Squarespace, Wix, WooCommerce, BigCommerce, and commercetools have integrated. Salesforce announced ACP support in October 2025. Shopify's 1 million+ US merchants are coming soon.

The Universal Commerce Protocol

Four months after ACP launched, a different coalition unveiled a second standard.

The Universal Commerce Protocol (UCP) was co-developed by Shopify and Google, announced January 11, 2026 at the National Retail Federation conference in New York. Google CEO Sundar Pichai presented it. The co-developers include Etsy, Wayfair, Target, and Walmart. Over 20 companies endorsed it at launch, including Mastercard, Visa, Best Buy, Home Depot, Macy's, American Express, and Stripe. I broke down UCP and its strategic implications the week it launched on the podcast.

Where ACP is tightly focused on the checkout flow, UCP is designed as a full commerce standard covering discovery through post-purchase. Its architecture is modeled after TCP/IP, with three layers:

UCP is protocol-agnostic. It supports REST, MCP, A2A, and AP2 (Agent Payments Protocol, Google's standard for agent-initiated payments). ACP currently supports REST and MCP.

Discovery works through a published profile at /.well-known/ucp, similar to how A2A agents publish their capabilities at /.well-known/agent-card.json (covered in Part 3). Both agents and merchants declare their capabilities, and on each request, the system computes the intersection of what they can do together. Ashish Gupta, VP/GM of Merchant Shopping at Google, described the logic: "The shift to agentic commerce will require a shared language across the ecosystem."

The two protocols reflect different strategic positions. ACP, built by the company running the AI agent (OpenAI) and the company processing the payment (Stripe), is optimized for getting transactions through ChatGPT quickly. UCP, built by the company hosting the merchants (Shopify) and the company running search (Google), is designed for a multi-agent future where many AI platforms compete for the same shoppers.

The good news for merchants: these aren't mutually exclusive. Shopify merchants can serve both simultaneously. The same products appear in ChatGPT via ACP and in Google AI Mode via UCP. Shopify's Agentic Storefronts handle the multi-protocol complexity, syndicating catalog data across ChatGPT, Google AI Mode, Microsoft Copilot, and Perplexity from a single admin panel.

Vanessa Lee, Shopify's VP of Product, framed the company's position: "Agentic commerce has so much potential to redefine shopping and we want to make sure it can scale."

The Trust Problem: Payments Without People

Both protocols face the same foundational challenge: how do you process a payment when the person with the credit card isn't the one at the checkout?

Traditional commerce treats credential possession as a trust signal. If you have the card number, the expiry date, and the CVV, you're probably the cardholder. Agentic commerce breaks this assumption. The agent has been authorized to act on the buyer's behalf, but it's not the buyer. As Stripe's Kevin Miller wrote in his October 2025 blog post: "Trust can't be inferred. It has to be explicitly granted, scoped, and enforced in code."

Javelin Strategy & Research, cited by Visa, describes this as the shift from "card-not-present" to "person-not-present" transactions. It's a useful framing. Card-not-present fraud was the defining challenge of e-commerce. Person-not-present fraud is the defining challenge of agentic commerce.

Shared Payment Tokens

Stripe's solution is the Shared Payment Token (SPT), a new payment primitive designed specifically for agent transactions. Here's how it works:

1. The buyer saves a payment method with the AI platform (e.g., ChatGPT)
2. When approving a purchase, the AI platform issues an SPT scoped to the specific merchant, capped at the checkout amount, with a time limit
3. The AI platform sends the SPT to the merchant via ACP
4. The merchant creates a Stripe PaymentIntent using the token
5. Stripe processes the payment, applying fraud detection in real time

The buyer's actual card details are never shared with the merchant or the agent. Each token is programmable (scoped by merchant, time, and amount), reusable across platforms, and revocable at any time. For existing Stripe merchants, enabling SPTs requires "as little as one line of code."

The Payment Networks Respond

The card networks have launched their own standards. Visa introduced the Trusted Agent Protocol in October 2025, an open framework built on HTTP Message Signatures that helps merchants distinguish legitimate AI agents from malicious bots. Developed in collaboration with Cloudflare, it has feedback from Adyen, Checkout.com, Microsoft, Shopify, Stripe, and Worldpay among others.

Mastercard launched Agent Pay in April 2025, introducing "Agentic Tokens" that build on their existing tokenization infrastructure. Each agent action uses permissions and limits defined by the consumer. Mastercard CEO Michael Miebach described agent-led payments as a "significant paradigm shift" for the industry. US issuers were enabled in November 2025, with global rollout in early 2026.

PayPal joined the ACP ecosystem on October 28, 2025, enabling PayPal wallets for ChatGPT checkout and building an ACP server that connects its global merchant catalog without requiring individual merchant integrations.

Google launched its own payment standard in parallel. The Agent Payments Protocol (AP2), announced September 2025 with 60+ industry partners, uses Verifiable Digital Credentials and a cryptographic Mandate system to create tamper-evident proof of user consent at every step of the transaction. AP2 is payment-agnostic, supporting credit and debit cards, real-time bank transfers, and even stablecoins via a Coinbase x402 extension. It's integrated directly into UCP.

Fraud Without Fingerprints

Traditional fraud detection relies on human behavioral signals: mouse movements, typing patterns, browsing behavior, session duration. AI agents have none of these. A legitimate agent transaction can look indistinguishable from a sophisticated bot attack.

Stripe addressed this by building what they describe as "the world's first AI foundation model for payments," a transformer-based model trained on tens of billions of transactions. The model treats each charge as a token and behavior sequences as context, ingesting signals including IPs, payment methods, geography, device characteristics, and merchant traits. When SPTs are used, Stripe Radar relays risk signals including dispute likelihood, card testing detection, and stolen card indicators to help "differentiate between high-intent agents and low-trust automated bots."

The attack surface is also novel. Researchers demonstrated in a June 2025 study that e-commerce agents are susceptible to visual prompt injection: malicious content embedded in product listings can hijack agent behavior during shopping tasks. All agents tested were vulnerable. A separate study accepted to IEEE S&P 2026 found that 13% of randomly selected e-commerce websites had already exposed their chatbot plugins to indirect prompt injection via third-party content like product reviews. And a January 2025 paper on authenticated delegation argues that for agentic commerce to function at scale, the industry needs standardized mechanisms to "explicitly delegate authority to agents, transparently identify those agents as AI, and enforce human-centered choices around security and permissions." SPTs, the Trusted Agent Protocol, and Agent Pay are all early answers to that challenge.

The concern is real on the consumer side too. 88% of consumers surveyed by Javelin are concerned that AI will be used for identity fraud, according to Visa's analysis. Building trust infrastructure that works for agent transactions is the prerequisite for agentic commerce scaling beyond early adopters.

Who's Already Selling to AI

Despite the infrastructure still being built, adoption is moving fast.

AI platforms with commerce capabilities:

Merchants and brands on board:

The early adopter list reads like a mall directory. URBN (parent of Anthropologie, Free People, and Urban Outfitters), Etsy, Coach, Kate Spade, Glossier, Vuori, Spanx, SKIMS, Ashley Furniture, Revolve, and Halara are among those onboarding to Stripe's Agentic Commerce Suite. Walmart and Instacart are live on ChatGPT. Gymshark, Everlane, and Monos are live on Google AI Mode via UCP.

E-commerce platforms enabling it:

Shopify's 1 million+ US merchants are eligible for ChatGPT integration. BigCommerce, Wix, Squarespace, WooCommerce, and commercetools have integrated with Stripe's Suite. Salesforce Commerce Cloud announced ACP support in October 2025, with new Agentforce agents for merchant, buyer, and personal shopper workflows.

The Market

The market projections vary widely, which tells you how early we are. McKinsey projects $1 trillion in US retail revenue orchestrated by agents by 2030, scaling to $3-5 trillion globally. Gartner predicts 90% of B2B purchases will be handled by AI agents within three years, intermediating $15 trillion in spending by 2028. Forrester predicts that by 2026, one-third of retail marketplace projects will be deserted as answer engines steal traffic.

The consumer side is more cautious. A Contentsquare survey of 1,300 US consumers found 30% willing to let an AI agent complete a purchase on their behalf. A YouGov survey of 1,287 US adults found 65% trust AI to compare prices, but only 14% trust it to actually place an order. Among Gen Z, that number rises to 20%. The gap between "I'll let AI help me shop" and "I'll let AI buy for me" is where we are right now.

But the traffic is already there. AI-driven traffic to US retail websites grew 4,700% year-over-year by mid-2025, according to Adobe Analytics. Shopify reported that orders attributed to AI searches grew 11x since January 2025. OpenAI estimates approximately 2% of all ChatGPT queries are shopping-related, roughly 50 million shopping queries daily across a user base of 700 million weekly users.

Academic research is starting to reveal what happens when agents do the buying. A Columbia Business School and Yale study (August 2025) introduced ACES, the first agentic e-commerce simulator, and tested six frontier models including Claude and GPT-4. They found that AI shopping agents exhibit "choice homogeneity," concentrating demand on a small number of products and showing strong position biases in how listings are ranked. The researchers warn of winner-take-all dynamics and the emergence of "AI-SEO," where sellers optimize listings specifically for agent behavior rather than human preferences. A February 2026 study on personalized product curation found that current agentic systems remain "largely insufficient" for tailored product recommendations in open-web settings. The agents are getting better at buying. They're not yet great at buying the right thing for a specific person.

The infrastructure is being built regardless of whether consumers are fully ready. When they are, the businesses that prepared will be the ones the agents can find.

How to Get Started

The good news: for most businesses, the entry point is simpler than you'd expect.

If you're on Shopify, you may already be selling to AI. Agentic Storefronts are active by default for eligible US merchants. Your products are syndicated to ChatGPT, Google AI Mode, Microsoft Copilot, and Perplexity from your existing Shopify admin. Check your dashboard for the agentic channel settings and ensure your product data (descriptions, images, categories) is clean and complete.

If you're on Stripe, enabling Shared Payment Tokens for ACP requires as little as one line of code. The Agentic Commerce Suite handles catalog syndication, checkout, and fraud detection. Connect your product catalog, select which AI agents to sell through, and you're live.

If you're on BigCommerce, Wix, Squarespace, or WooCommerce, integrations with Stripe's Suite are available. BigCommerce described the shift from "months of bespoke engineering work" per AI platform to "a single, configurable integration."

Regardless of platform, the protocol integrations get you connected. But agents still need to find and understand your products. This is where the work from Part 2 (getting cited) and Part 4 (being agent-readable) converges with commerce.

Audit your product data. Agents parse your catalog programmatically. Every product needs:

• A descriptive, specific title ("Men's Organic Cotton Crew Neck T-Shirt, Navy" not "Blue Shirt")
• A complete description including materials, dimensions, care instructions, and use cases
• Accurate, real-time pricing and stock availability
• High-quality images with descriptive alt text
• Consistent categorization across your catalog

Add structured markup. At minimum, every product page should include Product schema with name, description, image, sku, and brand, plus nested Offer schema with price, priceCurrency, availability, and seller. If you have reviews, add AggregateRating. This is the machine-readable layer that agents parse when direct protocol integrations aren't available. I talked about this with Duane Forrester, who co-launched Schema.org while at Bing, on the podcast. His argument: consistent structured data builds what he calls "machine comfort bias," where AI systems develop a preference for sources that have proven reliable over time.

Test your agent visibility. Open ChatGPT, Perplexity, and Google AI Mode and ask them to recommend products in your category. If yours don't appear, agents can't sell them. View your product pages in reader mode or a text-based browser to see what agents see when they visit your site directly (covered in Part 4).

Track agent-driven traffic. ChatGPT appends utm_source=chatgpt.com to referral links. Perplexity and other AI platforms leave similar referral signatures. Set up segments in your analytics to isolate AI-referred visits and monitor conversion rates separately from human traffic. The numbers are small now, but the 4,700% year-over-year growth in AI traffic to retail means they won't stay small.

Walmart CEO Doug McMillon put it directly: "For many years now, eCommerce shopping experiences have consisted of a search bar and a long list of item responses. That is about to change."

Whether it changes next quarter or next year for your business depends on whether your product data is ready when the agents come looking.

Key Takeaways

• Checkout is becoming a protocol, not a page. In agentic commerce, the AI agent handles the interface; the merchant processes the order. Two open standards, ACP (Stripe + OpenAI) and UCP (Shopify + Google), define how this works.

• Both protocols are open and growing fast. ACP launched in September 2025 and powers Instant Checkout in ChatGPT. UCP launched in January 2026 with endorsements from Mastercard, Visa, Walmart, and Target. They're complementary, not mutually exclusive. Shopify merchants can serve both simultaneously.

• Shared Payment Tokens solve the "person-not-present" problem. When the buyer isn't at the checkout, traditional trust signals break down. SPTs are programmable, scoped, time-limited, and revocable, letting agents initiate payments without ever seeing the buyer's card details.

• Payment networks are building their own standards. Visa's Trusted Agent Protocol and Mastercard's Agent Pay provide authentication and fraud frameworks specific to agent transactions. PayPal joined the ACP ecosystem. The payments infrastructure for agentic commerce is taking shape across the industry.

• Major brands are already live. Etsy, Walmart, Instacart, Glossier, SKIMS, Coach, and dozens more are selling through AI agents today. E-commerce platforms including Shopify, BigCommerce, Wix, Squarespace, and WooCommerce have integrations available.

• Consumer trust is lagging behind infrastructure. Only 14% of consumers currently trust AI to place orders on their behalf. But AI-driven traffic to retail grew 4,700% in a year. The infrastructure is being built for the adoption curve that follows.

This is the final article in a five-part series on the agentic web. Part 1 framed the shift from SEO to AAIO. Part 2 covered how to get cited by AI. Part 3 mapped the protocols. Part 4 explained how agents perceive your website. This article covered where it all leads: transactions.

The thread connecting all five parts is straightforward. Structured data helps AI find you. Clean content helps AI cite you. Accessible HTML helps AI navigate you. Structured commerce protocols help AI buy from you. It's the same principle at every layer: make your business machine-readable, and the machines will do business with you.

Kevin Miller, Stripe's Head of Payments, captured the moment: "Stripe spent the last 15 years optimizing commerce for human shoppers. Now, we're starting to do the same with agents."

The agents are already shopping. The question is whether they can find your store.