ACP enrollment: what merchants should check before integrating

Implementing ACP and joining a shopping platform are separate steps. Start with the merchant program you want to serve, confirm its current requirements and build only the capabilities that integration will use.

Reviewed October 1, 2026 · 5 min read

The Agentic Commerce Protocol (ACP), developed by OpenAI and Stripe, defines commerce interactions between agents and businesses. It is an open specification, not an automatic listing service. A merchant can implement the protocol and still need approval or configuration for a particular platform.

Before writing an integration, identify the target platform, the supported specification version and the customer journey it expects. Product discovery, checkout and payment handling have different requirements.

Separate discovery, checkout and participation#

Three related pieces often get described as 'ACP enrollment.' Treat them separately when scoping the work.

Product data describes what you sell. Checkout capabilities create and update a transaction. Platform participation determines whether a particular assistant will make those products or actions available. The ACP project explicitly notes that implementation does not automatically list your business with AI platforms.

A shared catalog can feed several integrations, but each destination has its own schema, eligibility rules and update process. An accepted OpenAI feed is not automatically a valid Google feed, and publishing an API does not establish a connection to either platform.

Check the current integration contract#

Use the ACP repository for versioned specifications and OpenAI's merchant page for ChatGPT participation. Confirm which capabilities your payment provider and target platform actually support before relying on an announcement or older tutorial.

ACP can be exposed through supported REST or MCP integration patterns. An existing MCP server may provide a useful connection layer, but it does not supply missing checkout rules, payment support or platform approval.

What is worth implementing now#

A practical sequence is to establish the destination first, then prepare the data and actions it requires:

1. Confirm participation. Identify the merchant application, eligibility conditions, supported markets and exact integration offered.
2. Prepare the catalog. Use stable identifiers, accurate descriptions, variants, prices, availability and clear fulfillment terms.
3. Validate the destination format. Map your source data to the required schema and inspect ingestion errors.
4. Implement checkout only where required. Connect it to your order and payment systems, using the version supported by the participating platform.
5. Test the complete lifecycle. Cover success, rejection, expired quotes, retries, cancellation and refund or support handoffs.

Technical details that trip teams up#

Once a target integration is confirmed, review these areas with the engineers responsible for orders and payments. They affect real customer outcomes.

Understand the payment boundary. A supported delegated payment mechanism may pass a scoped token instead of raw card details. Validate that token through the documented provider flow, enforce its limits and handle failures explicitly. The exact responsibilities depend on the provider and integration.

Design for retries. If a client times out after your server creates an order, it must be able to recover the result without creating another one. Use the protocol's idempotency contract and test concurrent as well as repeated requests.

Authenticate incoming requests and verify webhook signatures where the integration uses them. Validate all inputs, reject unsupported state transitions and retain enough event information to investigate a failed order without logging payment secrets.

In a marketplace or Stripe Connect setup, confirm which account owns the payment objects and receives settlement. The correct charge model depends on your integration. Test against the intended merchant account rather than assuming a successful API response proves the money went to the right place.

Choose the implementation your business needs#

Build an ACP integration when a participating application or provider can use it and the customer workflow justifies the maintenance. A hosted platform may handle part of that work, but ask what is live, which markets it covers and what you remain responsible for.

Keep catalog ownership separate from channel-specific mappings. That makes it easier to adapt when a platform changes without rebuilding the underlying offer data. The protocol comparison helps distinguish the roles of ACP, UCP and MCP.