ACP - Agentic Commerce Protocol: Shopify Guide

What Is the Agentic Commerce Protocol (ACP)?

The Agentic Commerce Protocol (ACP) is an open protocol co-developed by OpenAI and Stripe, announced in September 2025. It defines a technical standard that allows AI agents - such as ChatGPT, custom GPTs, and autonomous assistants - to discover products, compare offers, and complete purchases on behalf of users without leaving the conversation.

In practice, ACP is the invisible engine behind ChatGPT Shopping. When a user asks ChatGPT “find me an SPF 50 organic sunscreen for sensitive skin,” the AI agent uses ACP to query merchant catalogs, compare prices, verify availability, and offer a secure checkout via Stripe.

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).

March 2026: The Pivot to Visual Product Discovery

On March 24, 2026, OpenAI announced a significant shift in its commerce strategy. Instant Checkout - the ability to purchase directly within the ChatGPT interface - was discontinued after struggling with merchant adoption (only ~12 active merchants). In its place, OpenAI launched a visual product discovery experience powered by ACP, where ChatGPT recommends products and redirects buyers to the merchant’s own checkout.

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"
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       v
[1] ChatGPT interprets the purchase intent
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       v
[2] ACP agent queries compatible catalogs (Discovery)
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       v
[3] Agent compares prices, reviews, stock, shipping (Comparison)
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       v
[4] Agent presents the best options to the user
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       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 the way HTTP standardized the web: 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.

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).

A store that supports only one protocol is giving up 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:

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 - The 9 factors that determine your AI visibility
• Sell on ChatGPT - Agentic Storefronts and Shopify optimization for ChatGPT Shopping
• UCP: Universal Commerce Protocol - The Google + Shopify protocol for AI agents
• Perplexity Shopping - Merchant guide and readiness score
• Schema.org for Shopify - Technical guide to Product and Offer structured data
• Pricing and AI Visibility - How agents compare your prices and promotions
• Shipping & Returns - Critical trust signals for AI agents
• Robots.txt and AI Crawlers - Configure access for GPTBot, ClaudeBot and PerplexityBot
• AI Buyer Score - How AI agents evaluate and rank your products

Ready to check your store? Run a free GEO audit →

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.