ACP Protocol Guide: Complete Shopping Within ChatGPT

What is ACP?

ACP (Agentic Commerce Protocol) is a shopping protocol jointly released by OpenAI and Stripe. It enables users to complete product purchases directly within ChatGPT conversations.

ACP File Structure

The ACP configuration file is located at /agent.json in the website root:

{
  "schema_version": "1.0",
  "merchant": {
    "name": "Your Brand",
    "domain": "yourbrand.com",
    "logo_url": "https://yourbrand.com/logo.png"
  },
  "product_feed_url": "https://yourbrand.com/products.xml",
  "checkout_enabled": true,
  "checkout_api_url": "https://yourbrand.com/api/checkout",
  "payment_providers": ["stripe"],
  "supported_currencies": ["USD", "EUR", "GBP"],
  "shipping_countries": ["US", "CA", "GB", "DE", "FR"],
  "contact_email": "support@yourbrand.com"
}

Configuration Steps

1. Prepare Product Feed

Create a compliant product data feed including:

Product name, description, images

Price and currency

Stock status

SKU and GTIN (if available)

2. Generate agent.json

Use GeoAction's Agent Config Generator to automatically generate the configuration file.

3. Integrate Stripe Payments

ACP uses Stripe as the payment gateway. Ensure your website has Stripe integrated:

Create Stripe account

Get API keys

Implement Checkout API

4. Implement Checkout API

Create an API endpoint to handle purchase requests from ChatGPT:

POST /api/checkout
{
  "product_id": "xxx",
  "quantity": 1,
  "payment_method": "stripe"
}

5. Deploy and Verify

Upload agent.json to the website root, use GeoAction to verify configuration.

Important Field Descriptions

Field	Required	Description
merchant.name	✅	Merchant brand name
merchant.domain	✅	Merchant domain
productfeedurl	✅	Product data feed URL
checkout_enabled	✅	Whether checkout is enabled
payment_providers	✅	Supported payment methods
shipping_countries	✅	Countries with shipping

Security Considerations

Verify Request Source: Ensure API requests come from OpenAI

Protect API Keys: Don't expose Stripe keys on frontend

Implement Rate Limiting: Prevent API abuse

Log Transactions: Track all AI-initiated transactions

Differences from UCP

Aspect	UCP	ACP
Publisher	Google	OpenAI + Stripe
Main Platform	Google Search, Gemini	ChatGPT
Payment Integration	Google Pay	Stripe
Config File	.well-known/ucp	agent.json

Recommendation: Configure Both

To maximize AI traffic, configure both UCP and ACP to cover both Google and OpenAI ecosystems.