Agentic Commerce: ChatGPT and Gemini as the Checkout

Part of EPR's AdTech & MarTech pillar 2026 · AdTech & MarTech CSI 2026 · Retail Media 2026 · Citation Share Index

By the Everything-PR Editorial Team

Published June 2026. Updated October 11, 2026.

Agentic commerce is the category in which an AI agent completes the purchase for the consumer, inside the conversation. OpenAI announced Instant Checkout on October 14, 2025, with Walmart as founding partner and Stripe running payments. Google Gemini followed with the Universal Commerce Protocol on January 11, 2026, anchored by Walmart again. The brand the engine names gets the sale before the buyer evaluates an alternative.

OpenAI announced Instant Checkout on October 14, 2025, with Walmart as a founding launch partner. Google Gemini announced its Universal Commerce Protocol on January 11, 2026, also with Walmart as anchor. The category that emerges turns the answer engine itself into the sales channel. The consumer asks ChatGPT for a recommendation. ChatGPT recommends a product. ChatGPT completes the purchase inside the conversation, without the buyer ever visiting the retailer's website.

This is the single structural shift that turns answer-engine visibility from a marketing metric into a sales-channel revenue line. This is the operating reference on what agentic commerce is, who runs it, and what brand and retail communications operators need to know.

What Agentic Commerce Is

Agentic commerce is the category in which a software agent, typically an AI assistant or large language model, completes a consumer purchase on behalf of the consumer. The agent receives the consumer's intent ("find me a moisturizer for sensitive skin under $40"), evaluates available products against the stated criteria, recommends a specific product, and executes the transaction (payment, shipping, account credential management) inside the agent's interface.

The category has three operational variants. Engine-native commerce, where the AI engine itself executes the transaction (OpenAI Instant Checkout, Google Gemini Universal Commerce Protocol). Browser-agent commerce, where a separate AI agent operates the consumer's browser to complete purchases on third-party sites (Perplexity Comet, Anthropic's Computer Use, OpenAI Operator, Adept). Retailer-side agent commerce, where a retailer deploys an AI shopping assistant inside its own ecosystem (Walmart Sparky, Amazon Rufus). All three are in production at varying scale.

The Two Anchor Launches

OpenAI Instant Checkout, October 14, 2025. Announced in partnership with Walmart, Stripe, and a launch portfolio of retail brands. The product lets ChatGPT users complete purchases inside the conversation interface. Stripe handles the payment infrastructure. Walmart provides the anchor retail catalog and fulfillment. Subsequent launch partners expanded the available retailer set throughout late 2025 and early 2026.

Google Gemini Universal Commerce Protocol, January 11, 2026. Announced as an open commerce protocol allowing any merchant to integrate with Gemini's agentic-commerce interface. Walmart, again, anchored the launch with the largest retail catalog integration. Google positioned the Protocol as the open-standard alternative to OpenAI's more vertically integrated Instant Checkout model.

The Walmart double-anchor is not coincidence. Walmart has invested aggressively in becoming the agentic-commerce infrastructure layer that the AI engines plug into, betting that the AI engine layer commoditizes faster than the underlying retail fulfillment infrastructure. The bet appears to be paying off, because Walmart's agentic-commerce integration is now the most operationally mature in the category. The same logic that built the retail media walled gardens is now being applied one layer up, at the agent.

How does the Perplexity Comet browser change online buying?

Perplexity's Comet is an agentic browser that reads pages, clicks, types, and completes multi-step purchases on the open web for the user. It is a Chromium-based client with the Perplexity answer engine in the address bar and an execution layer that takes actions across sites. Perplexity opened Comet broadly in 2025 and moved the client to free access to compete with ChatGPT's Atlas browser and Google's agentic push inside Chrome.

For twenty years the funnel ran search, click, site, cart, checkout, and each layer had an owner and a business model. Agentic browsing collapses the middle. The user states what they want, Comet reads the answer, opens the merchant, fills the fields, and submits the order, so the brand's site becomes an endpoint the agent visits on the way to a decision it already made. Three consequences follow for communications and marketing teams.

Traffic-based measurement breaks, because sessions, bounce rate, and referral logs misread agent behavior, and analytics platforms cannot cleanly separate a Comet transaction from a human one. Citation Share becomes the pre-buy layer, because a product the agent recommends in a Perplexity answer is in the consideration set before the merchant site opens. Merchant defenses do not scale: Amazon sued Perplexity over Comet acting on logged-in Amazon accounts, and according to EPR's coverage, the Ninth Circuit vacated the preliminary injunction on August 4, 2026, siding with Perplexity on whether an AI agent acting on a user's authorization can use a logged-in commercial site.

Brands should respond in four ways. Publish product data in machine-readable form, with Schema.org Product markup, canonical SKUs, clear pricing, and availability signals. Treat the answer, not the page, as the conversion surface. Earn independent citations from reviews, comparison articles, and Reddit threads, which agents weight over on-site marketing copy. And make returns, refunds, and customer service transactable, so that agent-driven purchases do not turn into chargebacks as volume climbs. For the shopping side of Perplexity, see How Perplexity Shopping Works for Brands.

Why This Matters to Brand and Retail Operators

Three structural consequences define what agentic commerce means for the brand and retail communications operator.

The consideration moment is collapsing into the transaction moment. In traditional ecommerce, the consumer researches across multiple sources (Google search, retailer sites, review aggregators, social media), narrows to a consideration set, visits the chosen retailer, and completes the purchase. In agentic commerce, the AI engine collapses all of those steps into a single conversational exchange. The brand that surfaces in the AI engine's recommendation gets the sale before the consumer ever evaluates alternatives. The brand that does not surface loses the transaction before knowing it existed. Which engine names you is now a commercial question. See The Five Answer Engines in 2026 for how each one selects.

The retailer-side selection becomes the structural moat. Inside agentic commerce, which retailers the AI engine can purchase from determines the available product set. Walmart's anchor partnership with both OpenAI and Google gives Walmart structural advantage that the smaller retail partners do not have. The category's commercial economics increasingly favor the retailers with the most operationally mature agentic-commerce integration, which in turn favors the brands that distribute through those retailers. The precedent is retail media, which is closed-loop, first-party, and owned by the retailer.

The product-feed infrastructure becomes the new SEO. Every product attribute that informs the AI engine's recommendation decision (pricing, availability, shipping, reviews, ingredient and material specifications, brand descriptions) must be present in the engine's retrievable data layer. Brands and retailers that invest in structured, machine-readable product data show up in the agentic-commerce response. Brands and retailers that rely on visual-presentation-driven product marketing do not. The discipline has a name: who controls the answer is now a supply-chain question about your own data.

The Vendor Map

Engine-native agentic commerce: OpenAI Instant Checkout (ChatGPT), Google Gemini Universal Commerce Protocol, Microsoft Copilot Shopping, Perplexity Shopping.

Browser-agent commerce: Perplexity Comet, Anthropic Computer Use, OpenAI Operator, Adept ACT-1, multiple emerging browser-automation agents.

Retailer-side agent commerce: Walmart Sparky, Amazon Rufus, Shopify Magic, plus emerging retailer-specific assistants across Target, Best Buy, and Lowe's.

Payment infrastructure: Stripe (OpenAI Instant Checkout), Adyen, PayPal, Apple Pay, Google Pay.

Product-feed and structured-data infrastructure: Salsify, Akeneo, Productsup, Syndigo, Feedonomics.

Related EPR Coverage

• AdTech and MarTech Pillar 2026
• Retail Media in 2026
• How Perplexity Shopping Works for Brands
• AI agents and agentic AI in 2026
• AdTech & MarTech AI Citation Share Index 2026
• The EPR Citation Share Index