What Is the Agentic Commerce Protocol (ACP) and How It Works

Agentic Commerce Protocol (ACP) OpenAI's commerce standard for connecting merchant product data and commerce capabilities with ChatGPT shopping experiences. ACP defines how merchant systems expose catalogs, inventory, pricing, checkout capabilities, and fulfillment options so an agent (for example, ChatGPT) can discover, query, and act on behalf of a shopper.

ACP is an interoperability layer: a set of schemas, endpoints, and behavioral contracts that sit between merchant back ends and conversational agents. It translates traditional e-commerce concepts—SKUs, variants, availability, shipping options, promotions, and payments—into a machine-readable, action-oriented surface an agent can use to complete tasks such as product discovery, price comparisons, cart building, and order submission.

What The Protocol Covers

ACP covers the core capabilities needed for a conversational shopping flow. That includes product metadata, inventory and availability signals, real-time pricing and promotions, shopping-cart operations, checkout and payment handoffs, fulfillment options (pickup, delivery, ship-to), and order status queries. It also includes capabilities for capability discovery (what a merchant supports) and version negotiation so agents can adapt behavior to each merchant's implementation.

• Product Data: Structured attributes, images, variants, and taxonomy mappings for agent-friendly search and recommendation.
• Inventory & Availability: Real-time stock levels and lead times to avoid selling items that cannot be fulfilled.
• Pricing & Promotions: Rules for discounts, dynamic pricing, and bundles so an agent can calculate totals correctly.
• Checkout & Payments: Handoffs or APIs to initiate payment flows while preserving PCI scope considerations.

Key Components And Architecture

ACP implementations typically consist of a capability descriptor (what endpoints and semantic actions the merchant supports), a set of REST/GraphQL endpoints or webhooks for operations, a data schema for product and offer metadata, and a secure authentication model (API keys, OAuth). A merchant’s ACP adapter may be a lightweight shim inside their platform or a middleware service for legacy systems.

Why It Matters To Merchants And Platforms

ACP reduces friction when integrating with conversational commerce providers because agents don’t need bespoke integrations for every merchant. That lowers engineering cost, shortens time-to-market for voice/chat storefronts, and makes merchant capabilities discoverable in a standard way. For merchants, that means more channels and higher conversion potential without doubling engineering effort.

How It Handles Data, Privacy, And Security

ACP is aimed at minimizing sensitive data exposure. Critical design patterns include tokenized checkout handoffs (so payment data stays in the merchant or payment provider scope), scoped OAuth for agent actions, and webhooks for asynchronous order updates. Merchants need to combine ACP with existing compliance controls—PCI DSS for payments, privacy controls for PII, and secure transport for all endpoints.

How It Varies Between Implementations

Vendors can implement ACP at different fidelity levels. A full implementation includes real-time inventory, promotions semantics, and complete checkout flows. A minimal implementation might only provide a read-only catalog and availability and use an external link for checkout. Markets and platform strategies will determine which features merchants prioritize.

Practical Implementation Example

Consider a direct-to-consumer apparel brand. They expose an ACP capability descriptor listing endpoints for product search, SKU availability, cart operations, and an order initiation endpoint that returns a checkout URL. When a shopper asks ChatGPT to find a running shoe in size 10 with a discount, the agent queries the product endpoints, applies price rules from the pricing endpoint, builds a cart using cart operations, and hands off the shopper to the merchant's secure checkout URL for payment completion.

• Label: Discovery: Agents use the product schema to match shopper intent to SKUs.
• Label: Cart Assembly: Cart endpoints create a temporary cart and return a cart identifier.
• Label: Checkout Handoff: Order initiation returns a merchant-controlled checkout URL or tokenized payment session.

Tips For Adopting ACP

Start with the smallest set of capabilities that deliver value: product search, availability, and a secure checkout handoff. Monitor agent-driven sessions separately so you can measure conversion lift and identify catalog or fulfillment gaps. Use capability descriptors so agents can adjust behavior automatically, and maintain versioning to avoid breaking integrations.

In short, the Agentic Commerce Protocol (ACP) standardizes how merchant systems present product and commerce capabilities to conversational agents, reducing integration cost and enabling richer, agent-driven shopping experiences while requiring merchants to map existing commerce functions into the ACP schema and preserve security and compliance controls.