Shop Fast Amazon

I want to use the "Shop Fast Amazon" service.

## Access model
This is a discovery-only external API. Calls go directly to the provider; the marketplace does not proxy, authenticate, or settle them.

## Setup
1. Use amazon-search to find Amazon products by query.
2. Use amazon-quote to price a selected product before purchase.
3. Do not use amazon-buy through the marketplace until quote, consent, and order records are supported.

## External Endpoints

### Amazon Buy
Method: POST
Direct URL: https://shop.fast.xyz/api/amazon/buy
Docs: https://shop.fast.xyz/.well-known/ucp
Auth: Discovery-only listing. Marketplace execution is not enabled yet.
curl -X POST "https://shop.fast.xyz/api/amazon/buy" \
  -H "Content-Type: application/json" \
  -d '{
  "quoteId": "quote_example",
  "buyerConsent": {
    "accepted": true,
    "acceptedAt": "2026-03-19T00:10:00.000Z"
  }
}'

Discovery-only endpoint. Shop Fast owns quote validation, buyer consent, purchase execution, and order records.

### Amazon Order Status
Method: POST
Direct URL: https://shop.fast.xyz/api/amazon/order-status
Docs: https://shop.fast.xyz/.well-known/ucp
Auth: Discovery-only listing. Marketplace execution is not enabled yet.
curl -X POST "https://shop.fast.xyz/api/amazon/order-status" \
  -H "Content-Type: application/json" \
  -d '{
  "orderId": "order_example"
}'

Discovery-only endpoint. Use Shop Fast as the source of truth for order, fulfillment, cancellation, and refund state.

### Amazon Quote
Method: POST
Direct URL: https://shop.fast.xyz/api/amazon/quote
Docs: https://shop.fast.xyz/.well-known/ucp
Auth: Discovery-only listing. Marketplace execution is not enabled yet.
curl -X POST "https://shop.fast.xyz/api/amazon/quote" \
  -H "Content-Type: application/json" \
  -d '{
  "quantity": 1,
  "productId": "B000EXAMPLE",
  "shipToCountry": "US",
  "paymentCurrency": "USDC"
}'

Treat the quote as provisional until Shop Fast returns a confirmed order.

### Amazon Search
Method: POST
Direct URL: https://shop.fast.xyz/api/amazon/search
Docs: https://shop.fast.xyz/.well-known/ucp
Auth: Discovery-only listing. Marketplace execution is not enabled yet.
curl -X POST "https://shop.fast.xyz/api/amazon/search" \
  -H "Content-Type: application/json" \
  -d '{
  "query": "usb-c charger",
  "country": "US"
}'

Use the returned product identifier with amazon-quote before any purchase attempt.