UCP (Universal Commerce Protocol)

from sardis import Sardis, UCPClient

sardis = Sardis(api_key="sk_...")
ucp = UCPClient(sardis)

# Discover merchant
merchant = ucp.discover("https://store.example.com")

# Create cart
cart = ucp.create_cart(
    merchant_id=merchant.merchant_id,
    items=[
        {"product_id": "laptop_pro_16", "quantity": 1}
    ]
)

print(f"Total: ${cart.total} {cart.currency}")

# Checkout and pay
order = ucp.checkout(
    cart_id=cart.cart_id,
    wallet_id=agent.wallet_id,
    shipping_address=user.shipping_address
)

print(f"Order placed: {order.order_id}")
print(f"Tracking: {order.tracking_number}")

# Subscribe to service
subscription = ucp.subscribe(
    merchant_id="saas_provider",
    plan="pro",
    billing_cycle="monthly",
    wallet_id=agent.wallet_id
)

print(f"Subscribed to {subscription.plan}")
print(f"Next billing: {subscription.next_billing_date}")

# Cancel subscription
ucp.cancel_subscription(
    subscription_id=subscription.subscription_id,
    reason="switching_providers"
)

# Check credit balance
balance = ucp.get_balance(
    merchant_id="api_provider",
    account_id=agent.account_id
)

if balance < 1000:
    # Auto-purchase more credits
    purchase = ucp.purchase_credits(
        merchant_id="api_provider",
        amount=5000,  # 5000 API credits
        wallet_id=agent.wallet_id
    )
    print(f"Purchased {purchase.amount} credits")

# Purchase digital asset
purchase = ucp.purchase(
    merchant_id="digital_marketplace",
    item_type="dataset",
    item_id="financial_data_2026_q1",
    wallet_id=agent.wallet_id
)

# Download asset
asset_url = purchase.download_url
download_file(asset_url, local_path="./datasets/")

{
  "version": "1.0",
  "merchant_id": "your_merchant_id",
  "name": "Your Store",
  "currencies": ["USDC", "USDT"],
  "payment_methods": ["crypto"],
  "endpoints": {
    "cart": "https://yourstore.com/ucp/cart",
    "checkout": "https://yourstore.com/ucp/checkout",
    "status": "https://yourstore.com/ucp/status"
  },
  "public_key": "0x..."
}

from flask import Flask, request, jsonify
from sardis import SardisClient

app = Flask(__name__)
sardis = SardisClient(api_key="sk_...")

@app.route('/ucp/cart', methods=['POST'])
def create_cart():
    data = request.json
    
    # Calculate cart total
    cart = {
        "cart_id": generate_cart_id(),
        "items": calculate_items(data['items']),
        "subtotal": calculate_subtotal(data['items']),
        "tax": calculate_tax(data['items']),
        "total": calculate_total(data['items']),
        "currency": data['currency'],
        "expires_at": (now() + timedelta(minutes=15)).isoformat()
    }
    
    # Store cart
    carts_db.save(cart)
    
    return jsonify(cart)

@app.route('/ucp/checkout', methods=['POST'])
def checkout():
    data = request.json
    cart = carts_db.get(data['cart_id'])
    
    # Generate payment address
    payment_address = sardis.wallets.get_address(
        wallet_id="merchant_wallet"
    )
    
    # Create order
    order = {
        "order_id": generate_order_id(),
        "cart_id": cart['cart_id'],
        "status": "pending",
        "payment_address": payment_address,
        "amount_due": cart['total'],
        "currency": cart['currency']
    }
    
    # Store order
    orders_db.save(order)
    
    return jsonify(order)

@app.route('/ucp/status', methods=['GET'])
def order_status():
    order_id = request.args.get('order_id')
    order = orders_db.get(order_id)
    
    # Check payment status
    payment = sardis.payments.get(
        merchant_wallet_id="merchant_wallet",
        order_id=order_id
    )
    
    if payment and payment.status == "completed":
        order['status'] = "completed"
        order['payment_confirmed'] = True
        order['tx_hash'] = payment.tx_hash
        
        # Fulfill order
        fulfillment = fulfill_order(order)
        order['fulfillment'] = fulfillment
    
    return jsonify(order)

{
  "receipt_id": "receipt_abc123",
  "order_id": "order_xyz789",
  "merchant": {
    "merchant_id": "merchant_def456",
    "name": "Example Store",
    "address": "123 Merchant St, City, State 12345",
    "tax_id": "12-3456789"
  },
  "customer": {
    "agent_id": "agent_ghi012",
    "name": "Shopping Assistant",
    "email": "[email protected]"
  },
  "items": [
    {
      "product_id": "prod_123",
      "name": "Premium Widget",
      "quantity": 2,
      "unit_price": "25.00",
      "total": "50.00"
    }
  ],
  "amounts": {
    "subtotal": "50.00",
    "tax": "4.50",
    "shipping": "5.00",
    "total": "59.50",
    "currency": "USDC"
  },
  "payment": {
    "method": "crypto",
    "token": "USDC",
    "chain": "base",
    "tx_hash": "0x...",
    "paid_at": "2026-03-03T10:10:00Z"
  },
  "receipt_url": "https://merchant.com/receipts/abc123",
  "issued_at": "2026-03-03T10:10:00Z"
}

# Verify merchant's public key
merchant_info = ucp.discover("https://merchant.com")

if not verify_merchant_signature(
    merchant_id=merchant_info.merchant_id,
    public_key=merchant_info.public_key,
    signature=merchant_info.signature
):
    raise UnverifiedMerchantError("Cannot verify merchant identity")

# Verify payment address
if not sardis.verify_address(
    address=checkout.payment_address,
    merchant_id=merchant.merchant_id
):
    raise InvalidAddressError("Payment address not verified")

# Verify receipt signature
receipt = order.receipt

if not verify_signature(
    message=receipt_hash(receipt),
    signature=receipt.signature,
    public_key=merchant.public_key
):
    raise InvalidReceiptError("Receipt signature invalid")