# Agentic Commerce Protocol (ACP): Sell Through ChatGPT Agents > How ACP powers ChatGPT Shopping and autonomous purchasing. Enable it on Shopify, audit your readiness, ACP vs UCP compared. - Canonical HTML: https://verityscore.io/en/kb/acp-agentic-commerce-protocol/ - Markdown alternate: https://verityscore.io/en/kb/acp-agentic-commerce-protocol.md - Language: en - Content type: kb - Published: 2026-03-24 - Updated: 2026-05-05 - Tags: acp, agentic-commerce, chatgpt-shopping, stripe, shopify - Audit zone: ACP ## What Is the Agentic Commerce Protocol (ACP)? Update as of May 5, 2026: separate **ACP for product discovery**, **Instant Checkout for eligible merchants/products**, and **merchant-owned checkout** when the user completes purchase on the merchant site or app. Verity Score should not conclude "eligible" or "excluded" from a readiness score alone. ACP readiness is a proxy: catalog quality, structured data, policies, availability, pricing, feeds, and OpenAI crawler access.
ACP (Agentic Commerce Protocol) workflow: 4 capabilities (Discovery, Cart, Checkout, Post-Purchase) with ACP OpenAI/Stripe vs UCP Google/Shopify comparison
Figure 1 - The 4 ACP protocol capabilities and comparison with UCP
The Agentic Commerce Protocol (ACP) is a protocol co-developed by OpenAI and Stripe, announced in September 2025. It provides a technical layer for connecting merchant data to ChatGPT Shopping experiences: product discovery, comparison, availability, promotions, and, depending on eligibility, agentic purchase flows. In practice, ACP helps ChatGPT Shopping access more complete and up-to-date product information. When a user asks ChatGPT "find me an SPF 50 organic sunscreen for sensitive skin," ChatGPT can rely on structured data, merchant feeds/catalogs, and other sources to compare prices, availability, reviews, and product attributes. According to Stripe, over **100,000 merchants** were ACP-compatible by the end of 2025, and that number tripled in Q1 2026 (source: Stripe Commerce Report Q1 2026). ### 2026: Product Discovery and Merchant Checkout On March 24, 2026, OpenAI strengthened the **product discovery** side of ChatGPT Shopping and said it wants to give merchants more flexibility around checkout. This does not mean Instant Checkout disappeared everywhere: treat it as a specific capability available only according to integration and eligibility, while many journeys hand off to the merchant's checkout experience. Major retailers now integrated with ACP for discovery include **Target, Sephora, Nordstrom, Lowe's, Best Buy, The Home Depot, and Wayfair** (source: OpenAI, March 2026). Walmart introduced a dedicated in-app ChatGPT service supporting linking, loyalty programs, and Walmart payments. The ACP specification itself received three updates since launch: fulfillment enhancements (December 2025), capability negotiation (January 2026), and extensions for discounts and payment handlers (January 2026) - source: ACP GitHub repository. ## How ACP Works The ACP purchase journey unfolds in 5 steps, transparent to the user: ``` User: "I'm looking for a 30L waterproof hiking backpack" | v [1] ChatGPT interprets the purchase intent | v [2] ACP agent queries compatible catalogs (Discovery) | v [3] Agent compares prices, reviews, stock, shipping (Comparison) | v [4] Agent presents the best options to the user | v [5] User confirms → Secure checkout via Stripe (Purchase) ``` ### The 4 ACP Capabilities Each ACP-compatible merchant exposes 4 capabilities that AI agents can use: 1. **Discovery** - The agent can browse your catalog, read your product pages, and filter by attributes (size, color, price, availability). The more complete your schema.org, the better the agent understands your products. 2. **Cart** - The agent can build a cart for the user, manage variants (size M, navy blue), apply promo codes if available, and calculate shipping costs. 3. **Checkout** - Payment is handled natively by Stripe. The user never leaves ChatGPT: they confirm, pay via their saved method (card, Apple Pay, Google Pay), and receive a confirmation. 4. **Post-Purchase** - The agent can provide order tracking, shipping information, and facilitate returns. This capability is the least deployed so far but is rapidly expanding. ### Why ACP Is a Turning Point Before ACP, each AI platform built its own merchant integrations. Result: fragmentation, slow adoption, uneven experience. ACP standardizes [agentic commerce](/en/glossary#agentic-commerce) the way **HTTP standardized the web** ([Shopify, 2026](https://www.shopify.com/blog/agentic-commerce)): one protocol, thousands of merchants, billions of potential transactions. According to a Gartner study from January 2026, **35% of online purchases will involve an AI agent by 2028**. ACP-compatible merchants capture this demand today. ## ACP vs UCP: What Is the Difference? The agentic commerce market is structured around two major protocols. Understanding both is essential to maximize your AI visibility. | Criteria | ACP | UCP | |----------|-----|-----| | **Creators** | OpenAI + Stripe | Google + Shopify | | **Launch date** | September 2025 | March 2026 | | **Compatible agents** | ChatGPT, custom GPTs, OpenAI assistants | Google AI Mode, Gemini, third-party agents | | **Technical protocol** | REST API + Stripe Connect | REST + MCP + Agent-to-Agent (A2A) | | **Payment processor** | Stripe is central for Instant Checkout; other journeys can hand off to merchant checkout | Flexible (Shopify Payments, PayPal, etc.) depending on surface | | **Discovery** | Product data, merchant feeds/catalogs, schema.org, and accessible pages | Storefront Catalog MCP `/api/ucp/mcp` + schema.org/feeds | | **Checkout** | Instant Checkout for eligible cases or merchant handoff | Mostly merchant handoff depending on integration | | **Geography** | 46 countries (Q1 2026) | 23 countries at launch | | **Compatible merchants** | 300,000+ | 180,000+ at launch | | **Open source** | Partially (open specs) | Yes (full public specification) | ### Which One Should You Choose? The answer is straightforward: **both**. ACP and UCP are not competitors - they are complementary. ACP connects you to the OpenAI ecosystem (ChatGPT and its 300 million weekly users). UCP connects you to the Google ecosystem (AI Mode, Gemini, and potentially any third-party agent). Early 2026 data from checkout.com shows that merchants with **dual ACP + UCP implementation capture 40% more agentic traffic** than stores supporting only one protocol. The effort to add the second protocol is minimal - 80% of the technical prerequisites are shared - making dual implementation the highest ROI move in agentic commerce readiness. A store that supports only one protocol is giving up nearly half of its agentic traffic. ## How to Enable ACP on Shopify Enabling ACP on Shopify takes 5 steps. Estimated time: 30 to 60 minutes. ### Step 1: Verify Stripe Is Active ACP relies entirely on Stripe for payment processing. On Shopify: - **Shopify Payments** uses Stripe behind the scenes - you are already compatible - If you use a third-party processor (Mollie, Adyen), you will need to activate Shopify Payments alongside it or migrate - Check in **Shopify Admin → Settings → Payments** that Shopify Payments is active ### Step 2: Enable Agentic Storefronts Since December 2025, Shopify offers a dedicated option: 1. Go to **Shopify Admin → Settings → Sales Channels** 2. Look for **Agentic Storefronts** 3. Toggle ON "Allow AI agents to interact with your catalog" 4. Select the capabilities to expose: Discovery, Cart, Checkout This activation automatically generates the API endpoints that ACP agents use to query your catalog. ### Step 3: Verify Your schema.org Product ACP relies on schema.org to understand your products. Each product page must contain at minimum: - `@type: Product` with `name`, `description`, `image`, `sku` - `offers` with `price`, `priceCurrency`, `availability`, `url` - `brand` with `name` - `aggregateRating` if you have reviews (strongly recommended) - `shippingDetails` with delivery time and cost - `hasMerchantReturnPolicy` with return policy details On Shopify, most modern themes automatically generate basic schema.org Product markup. But `shippingDetails` and `hasMerchantReturnPolicy` are often missing - they need to be added manually or via an app. ### Step 4: Ensure Price Consistency ACP compares displayed prices with structured prices. Any inconsistency triggers a distrust signal: - The price in your schema.org `offers.price` must exactly match the price displayed on the page - Strikethrough prices (`compareAtPrice`) must be higher than the current price - The currency (`priceCurrency`) must match your target market (EUR for France, GBP for the UK) - OG prices (`og:price:amount`) must be synchronized with schema.org ### Step 5: Verify Real-Time Availability An AI agent recommending an out-of-stock product destroys user trust. Make sure: - Shopify inventory is synced in real time (no update delay greater than 15 minutes) - The schema.org `availability` field reflects actual stock (`InStock`, `OutOfStock`, `PreOrder`) - Sold-out variants are correctly marked ## The 5 ACP Readiness Criteria For an ACP agent to recommend your store with confidence, 5 criteria must be met: ### 1. Product Discovery (Complete Schema) The agent must understand your products unambiguously. This requires a complete schema.org Product with all fields mentioned in Step 3. Merchants with incomplete schemas are systematically deprioritized in ACP recommendations. **Benchmark**: stores in the top 10% of ACP recommendations have an average of 12 schema.org fields filled per product, compared to 5 for the average (source: Verity Score analysis of 15,000 stores, Q1 2026). ### 2. Price Accuracy (Consistent Prices) Displayed price, schema.org price, and OG price must be identical. Any divergence is a negative signal. ACP agents systematically cross-check pricing before recommending a product. ### 3. Checkout Capability (Stripe + Returns) Active Stripe, functional checkout, structured return policy in schema.org. Without `hasMerchantReturnPolicy`, the AI agent cannot inform users about return conditions - significantly reducing agentic conversion rate. ### 4. Fulfillment Info (Structured Shipping) The agent must be able to communicate delivery time and cost before checkout. The schema.org `shippingDetails` field is therefore critical. Include at minimum: shipping zone, estimated time, standard cost, and express cost. ### 5. Trust Signals (Reviews and Certifications) AI agents prioritize stores with verifiable trust signals: customer reviews (`aggregateRating`), certifications (organic, vegan, etc.), years in business, number of orders processed. The more structured these signals are, the more the agent integrates them into recommendations. ## How Verity Score Measures Your ACP Readiness Verity Score automatically audits your ACP compatibility and assigns an **ACP Readiness score out of 100**, broken down into 5 dimensions: | Dimension | Weight | What Is Checked | |-----------|--------|-----------------| | Schema completeness | 30% | Number of schema.org Product fields filled, presence of critical fields | | Price coherence | 20% | Consistency between schema price / displayed price / OG price / compareAtPrice | | Checkout readiness | 20% | Stripe/Shopify Payments detection, structured return policy | | Fulfillment data | 15% | Presence of shippingDetails, structured delivery time and cost | | Trust signals | 15% | AggregateRating, review count, detected certifications | ### Score Interpretation - **80-100**: Your store is ACP-ready. AI agents can recommend your products with confidence. - **60-79**: Compatible but with gaps. Some agents may skip you in favor of better-structured competitors. - **40-59**: Not ready. Major corrections needed on schema.org and/or Stripe configuration. - **0-39**: Incompatible. The AI agent cannot reliably interact with your store. The audit identifies each gap precisely and provides actionable recommendations with the exact path in your Shopify admin. ## Merchant Checklist: 8 Actions to Enable ACP Here are the 8 concrete actions to make your Shopify store ACP-compatible: 1. **Activate Shopify Payments** - Admin → Settings → Payments → Shopify Payments → Activate. If already active, verify that Stripe Connect is properly configured. 2. **Enable Agentic Storefronts** - Admin → Settings → Sales Channels → Agentic Storefronts → Toggle ON. Select all capabilities (Discovery, Cart, Checkout). 3. **Enrich schema.org Product** - Verify each product page contains: name, description, image, sku, brand, offers (price, currency, availability), aggregateRating. Use an app like JSON-LD for SEO or Smart SEO if your theme does not generate them natively. 4. **Add shippingDetails to schema** - Integrate shipping information into schema.org: zone, delivery time, cost. On Shopify, this typically requires a Liquid theme modification or a dedicated app. 5. **Add hasMerchantReturnPolicy** - Structure your return policy in schema.org with: return type (refund, exchange), timeframe (14, 30 days), conditions. Link it to your return policy page. 6. **Synchronize prices** - Verify that schema.org price = displayed price = og:price:amount. Watch currencies: a French store must use EUR, not USD. 7. **Verify real-time inventory** - Admin → Products → Inventory. Enable inventory tracking for each product. Verify that sold-out variants automatically switch to `OutOfStock` in schema. 8. **Run a Verity Score audit** - Go to Verity Score, enter your store URL, and get your ACP Readiness score in 90 seconds. Fix the identified gaps and re-run the audit to validate. ### Correction Priorities If your score is below 60, focus in this order: 1. Basic schema.org Product (name, price, availability) - immediate impact 2. Active Stripe/Shopify Payments - non-negotiable technical prerequisite 3. ShippingDetails + ReturnPolicy - strong differentiator 4. AggregateRating - AI agent trust booster 5. Cross-source price consistency - avoids distrust signals ## Related articles - [GEO Audit: Complete Guide](/en/kb/geo-audit) - The 9 factors that determine your AI visibility - [Sell on ChatGPT](/en/kb/sell-on-chatgpt-shopify) - Agentic Storefronts and Shopify optimization for ChatGPT Shopping - [UCP: Universal Commerce Protocol](/en/kb/ucp-universal-commerce-protocol) - The Google + Shopify protocol for AI agents - [Perplexity Shopping](/en/kb/perplexity-shopping) - Merchant guide and readiness score - [Schema.org for Shopify](/en/kb/schema-org) - Technical guide to Product and Offer structured data - [Pricing and AI Visibility](/en/kb/pricing-ai-visibility) - How agents compare your prices and promotions - [Shipping & Returns](/en/kb/shipping-returns) - Critical trust signals for AI agents - [Robots.txt and AI Crawlers](/en/kb/robots-crawlers) - Configure access for GPTBot, ClaudeBot and PerplexityBot - [AI Buyer Score](/en/kb/ai-buyer-score) - How AI agents evaluate and rank your products --- **Ready to check your store?** [Run a free GEO audit →](https://verityscore.io) ACP is not a passing trend. It is the standard that defines how AI agents will buy on our behalf tomorrow. Merchants who enable it today gain a decisive advantage over their competitors. ## FAQ ### What is the Agentic Commerce Protocol (ACP)? ACP is a protocol co-developed by OpenAI and Stripe to connect merchant data to ChatGPT Shopping experiences: product discovery, fresher product information, promotions, and for some eligible merchants/products, Instant Checkout. ### Do I need Stripe to enable ACP? Stripe is central to ACP and Instant Checkout, but it should not be described as the only product path. In Verity, the priority is product data quality, feed readiness, policies, crawler access, and merchant checkout handoff quality. ### Is ACP available in Europe? ChatGPT Shopping can show products to users in many countries, but merchant eligibility, direct feeds, and Instant Checkout depend on OpenAI/Shopify programs and region. Verity measures observable readiness signals, not a guaranteed activation. ### What is the difference between ACP and UCP? ACP is backed by OpenAI and Stripe and primarily powers ChatGPT Shopping. UCP is backed by Google and Shopify and powers Google AI Mode and Gemini. Both are complementary - a store should support both to maximize AI visibility. ### How do I know if my store supports ACP? Check three things: Stripe or Shopify Payments active, complete schema.org Product on your product pages, and Agentic Storefronts enabled in your Shopify admin. Verity Score automatically audits these criteria and gives you an ACP Readiness score out of 100. ### Is the Verity Score ACP audit free? Yes. The Verity Score public audit analyzes your ACP Readiness for free, including schema.org verification, Stripe configuration, and real-time availability checks. No installation required. ## Sources - [Shopify Agentic Commerce Blog](https://www.shopify.com/blog/agentic-commerce) (official) - [Perplexity Shopping: How to Optimize Your Store for AI (2026)](https://www.shopify.com/blog/perplexity-shopping) (official) - [The Complete Product Data Optimization Guide for Google's AI Shopping (2026)](https://www.efulfillmentservice.com/2026/01/the-complete-product-data-optimization-guide-for-googles-ai-shopping-2026/) (industry) - [Your Shopify Store Is on ChatGPT Shopping But Products Aren't Showing](https://metricusapp.com/blog/shopify-chatgpt-shopping-products-not-showing/) (industry)