What is the Agentic Commerce Protocol?

The Agentic Commerce Protocol (ACP) is an open standard co-developed by OpenAI and Stripe that enables AI agents to complete commercial transactions on behalf of users. It consists of three specifications: Product Feed, Agentic Checkout, and Delegated Payment.

Yes, the protocol specification is free and open source (Apache 2.0). Standard payment processing fees apply when using Stripe for payments.

Do merchants keep their customer relationships with ACP?

Yes, merchants remain the merchant of record and keep full control over customer relationships, including customer data, emails, and support.

How are payments secured in ACP?

ACP uses Shared Payment Tokens (SPTs) that are merchant-specific, amount-limited, time-limited, and single-use. The AI agent never sees actual payment credentials.

Which AI assistants support ACP?

ChatGPT supports ACP via its Instant Checkout feature. As an open standard, any AI platform can implement ACP support.

Error Codes

Reference for all error codes returned by the ACP API.

Error Response Format


{
  "error": {
    "code": "error_code",
    "message": "Human-readable description",
    "details": {}
  }
}

Authentication Errors (4xx)

Code	HTTP Status	Description
`invalid_signature`	401	Request signature verification failed
`missing_signature`	401	Required signature header missing
`expired_timestamp`	401	Timestamp outside acceptable window
`invalid_agent`	403	Agent not authorized for this merchant

Example


{
  "error": {
    "code": "invalid_signature",
    "message": "The request signature could not be verified"
  }
}

Session Errors

Code	HTTP Status	Description
`session_not_found`	404	Checkout session does not exist
`session_expired`	410	Session has expired
`session_cancelled`	410	Session was cancelled
`invalid_session_state`	400	Operation not valid for current state

Example


{
  "error": {
    "code": "session_expired",
    "message": "This checkout session has expired",
    "details": {
      "expired_at": "2024-01-15T10:30:00Z"
    }
  }
}

Cart Errors

Code	HTTP Status	Description
`product_not_found`	400	Product ID does not exist
`product_unavailable`	400	Product not available for purchase
`insufficient_inventory`	400	Not enough stock
`invalid_quantity`	400	Quantity must be positive integer
`cart_empty`	400	Cart has no items

Example


{
  "error": {
    "code": "insufficient_inventory",
    "message": "Only 2 items available",
    "details": {
      "product_id": "prod_123",
      "requested": 5,
      "available": 2
    }
  }
}

Payment Errors

Code	HTTP Status	Description
`payment_declined`	400	Payment was declined
`invalid_payment_token`	400	Payment token is invalid or expired
`payment_amount_mismatch`	400	Token amount doesn’t match total
`payment_currency_mismatch`	400	Token currency doesn’t match
`payment_already_captured`	400	Token has already been used

Example


{
  "error": {
    "code": "payment_declined",
    "message": "The payment method was declined",
    "details": {
      "decline_code": "insufficient_funds"
    }
  }
}

Shipping Errors

Code	HTTP Status	Description
`shipping_address_required`	400	Shipping address needed
`shipping_address_invalid`	400	Address validation failed
`shipping_not_available`	400	Cannot ship to this address
`shipping_option_invalid`	400	Selected shipping option not valid

Example


{
  "error": {
    "code": "shipping_not_available",
    "message": "We cannot ship to this address",
    "details": {
      "country": "XX",
      "supported_countries": ["US", "CA", "GB"]
    }
  }
}

Rate Limit Errors

Code	HTTP Status	Description
`rate_limit_exceeded`	429	Too many requests

Example


{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Rate limit exceeded. Retry after 60 seconds",
    "details": {
      "retry_after": 60
    }
  }
}

Server Errors

Code	HTTP Status	Description
`internal_error`	500	Unexpected server error
`service_unavailable`	503	Service temporarily unavailable

Handling Errors

JavaScript/TypeScript


try {
  const session = await createCheckoutSession(cart);
} catch (error) {
  if (error.code === 'insufficient_inventory') {
    // Show user available quantity
    const available = error.details.available;
    showMessage(`Only ${available} items available`);
  } else if (error.code === 'payment_declined') {
    // Request different payment method
    requestNewPaymentMethod();
  } else {
    // Generic error handling
    showError(error.message);
  }
}

Python


try:
    session = create_checkout_session(cart)
except ACPError as e:
    if e.code == 'insufficient_inventory':
        available = e.details['available']
        print(f"Only {available} items available")
    elif e.code == 'payment_declined':
        request_new_payment_method()
    else:
        print(f"Error: {e.message}")