> ## Documentation Index
> Fetch the complete documentation index at: https://learn.orbexa.io/llms.txt
> Use this file to discover all available pages before exploring further.

# ACP Agentic Commerce Protocol

> Complete guide to ACP, the open standard by Stripe for AI agentic commerce — Product Feed integration, Checkout API, and Delegate Payment flow.

# ACP — Agentic Commerce Protocol

> "An open standard for programmatic commerce flows between buyers, AI agents, and businesses."

## What Is ACP

ACP (Agentic Commerce Protocol) is an open standard **created by Stripe** that defines the protocol for programmatic commerce interactions between buyers, AI agents, and merchants. **OpenAI ChatGPT is the first implementer of ACP**.

ACP is not a single API. It consists of **two independent systems**:

| System               | Direction            | Hosted By       | Purpose                      |
| -------------------- | -------------------- | --------------- | ---------------------------- |
| **Product Feed**     | Merchant to OpenAI   | OpenAI platform | Product data synchronization |
| **Agentic Checkout** | AI agent to Merchant | Merchant-hosted | Checkout, payment, orders    |

**Protocol Status**: Beta (partner approval required)

**Spec Version History**:

* 2025-09-29 (initial release)
* 2025-12-12 (fulfillment capabilities)
* 2026-01-16 (capability negotiation)
* 2026-01-30 (extensions, discounts, payment processors) — current latest

**Official Resources**:

* Open specification: [agenticcommerce.dev](https://agenticcommerce.dev)
* OpenAI merchant docs: [developers.openai.com/commerce](https://developers.openai.com/commerce)
* GitHub: [github.com/agentic-commerce-protocol](https://github.com/agentic-commerce-protocol/agentic-commerce-protocol)
* Contact: [acp@stripe.com](mailto:acp@stripe.com)

## The Two Systems of ACP

### System 1: Product Feed (Product Data Sync)

Merchants **push product catalog data to the OpenAI platform**. There are two methods:

| Method               | Format                                      | Use Case                                     |
| -------------------- | ------------------------------------------- | -------------------------------------------- |
| **SFTP File Upload** | Parquet (zstd) / jsonl.gz / csv.gz / tsv.gz | Daily full catalog snapshots                 |
| **REST API**         | JSON                                        | Real-time incremental updates during the day |

**Best Practice**: Daily SFTP full sync + API real-time pushes for changes (prices, inventory, promotions).

### System 2: Agentic Checkout (Transaction Processing)

Merchants **implement 5 API endpoints** on their own servers. AI agents call these endpoints to complete transactions when a user confirms a purchase:

```
POST   /checkout_sessions            Create a checkout session
GET    /checkout_sessions/:id        Query session status
POST   /checkout_sessions/:id        Update session (shipping address, buyer info, etc.)
POST   /checkout_sessions/:id/complete  Complete payment
POST   /checkout_sessions/:id/cancel    Cancel session
```

Payment credentials are securely transmitted through the **Delegate Payment API** (hosted by Stripe) — merchants never touch raw card numbers.

## ACP vs. UCP Comparison

| Dimension             | ACP                                              | UCP                                    |
| --------------------- | ------------------------------------------------ | -------------------------------------- |
| **Created By**        | Stripe                                           | Google with Shopify and others         |
| **First Implementer** | OpenAI ChatGPT                                   | Multiple platforms                     |
| **Architecture**      | Merchant pushes data + merchant builds endpoints | Merchant builds API endpoints          |
| **Payment**           | Delegate Payment (vault token)                   | Payment Token Exchange                 |
| **Current Status**    | Beta (application required)                      | Open                                   |
| **Coverage**          | Product discovery + checkout + payment           | Checkout + identity + orders + payment |
| **Ecosystem**         | ChatGPT ecosystem                                | Cross-platform / cross-AI              |

## Merchant Onboarding Flow

1. **Apply for partner status** — Submit an application at [chatgpt.com/merchants](https://chatgpt.com/merchants)
2. **Get approved** — Stripe/OpenAI reviews merchant qualifications
3. **Configure SFTP** — Set up the file upload channel
4. **Prepare product data** — Format your catalog per the Product object specification
5. **Implement Checkout endpoints** — Deploy 5 API endpoints on your server
6. **Integrate Delegate Payment** — Connect to Stripe's payment delegation API
7. **Test and launch** — Validate with a small batch, then go live at full scale

## Chapter Directory (8 Chapters)

### Part I: Core Concepts

1. [ACP Core Concepts](/en/book-4/ch1-core-concepts) — Protocol architecture, four-party model, data flow
2. [Product Data Format](/en/book-4/ch2-product-data) — Product/Variant objects, pricing (minor units), media, availability

### Part II: Data Synchronization

3. [File Upload Integration](/en/book-4/ch3-file-upload) — SFTP specifications, sharding strategy, Feed Header
4. [REST API Integration](/en/book-4/ch4-api) — Feeds/Products/Promotions endpoints, authentication, idempotency

### Part III: Transaction Capabilities

5. [Promotions Management](/en/book-4/ch5-promotions) — Promotion objects, discount types, active periods

### Part IV: Quality and Operations

6. [Data Quality Best Practices](/en/book-4/ch6-data-quality) — ID stability, URL encoding, description formats, prohibited content
7. [Testing and Validation](/en/book-4/ch7-testing) — Small-batch validation, data compliance checks
8. [Frequently Asked Questions](/en/book-4/ch8-faq) — Common questions during onboarding

<Note>
  ACP is currently in Beta and requires partner approval. This book is based on ACP spec version 2026-01-30 and the OpenAI Commerce documentation. For the latest onboarding policies, visit [agenticcommerce.dev](https://agenticcommerce.dev).
</Note>