🚀 Production-ready .NET API template implementing Universal Commerce Protocol (UCP) - Google's new standard for commerce integration.

Universal Commerce Protocol (UCP) is a new open standard developed by Google, Shopify, Target, Walmart, and other major e-commerce players to standardize commerce operations across platforms. This template provides a complete UCP REST API implementation for merchants.

• ✅ Complete UCP REST API - All standard endpoints implemented
• ✅ UCP Discovery - /.well-known/ucp merchant profile endpoint
• ✅ Checkout Sessions - Create, get, update, complete, cancel
• ✅ Order Management - Get and update orders
• ✅ Strongly-typed models - Full C# models for all UCP types
• ✅ TODO-based implementation - Clear markers for your business logic
• ✅ No database dependencies - Use any database you want
• ✅ Lightweight - Minimal dependencies, maximum flexibility
• ✅ Swagger/OpenAPI - Interactive API documentation

git clone https://github.com/sahinhurcan/ucp.NET.git
cd ucp.NET/template/UCP.API
dotnet run

Navigate to http://localhost:5000 to see Swagger documentation.

All UCP REST API endpoints per the official specification:

• GET /.well-known/ucp - Merchant profile discovery

• POST /checkout-sessions - Create checkout session
• GET /checkout-sessions/{id} - Get checkout details
• PUT /checkout-sessions/{id} - Update checkout
• POST /checkout-sessions/{id}/complete - Complete checkout and create order
• POST /checkout-sessions/{id}/cancel - Cancel checkout session

• POST /checkout-sessions - Create checkout session
• GET /checkout-sessions/{id} - Get checkout details
• PUT /checkout-sessions/{id} - Update checkout
• POST /checkout-sessions/{id}/complete - Complete checkout and create order
• POST /checkout-sessions/{id}/cancel - Cancel checkout session

• GET /orders/{id} - Get order details
• PUT /orders/{id} - Update order

Each endpoint has clear TODO comments:

[HttpPost]
public async Task<IActionResult> CreateCheckout([FromBody] CheckoutCreateRequest request)
{
    // TODO: Implement your business logic here
    // 1. Validate line items against your product catalog
    // 2. Check inventory availability
    // 3. Calculate totals, taxes, and shipping costs
    // 4. Save checkout session to your database
    // 5. Return checkout response with calculated values
    
    throw new NotImplementedException("Implement in your business layer");
}

The template has TODO markers where you implement your business logic. You can:

• Store data in a database (SQL Server, PostgreSQL, MongoDB, etc.)
• Make API calls to external services
• Use in-memory storage
• Integrate with existing systems
• Any combination of the above

Simply fill in the TODO sections in each controller with your implementation!

All UCP protocol models in UCP.NET library:

• CheckoutCreateRequest / CheckoutUpdateRequest / CheckoutResponse
• LineItem / LineItemResponse
• Payment / PaymentResponse
• Fulfillment / FulfillmentResponse
• Order / OrderSummary
• UcpMetadata / Capability
• Price / PaymentHandler / PaymentCredentials
• FulfillmentMethod / ShippingDestination
• And more...

1. Platform discovers merchant capabilities

   GET /.well-known/ucp
   → Merchant profile with capabilities
   

2. Create checkout session

   POST /checkout-sessions
   {
     "line_items": [...],
     "currency": "USD",
     "buyer": {...},
     "payment": {...}
   }
   → Checkout ID and details
   

3. Update with payment/shipping

   PUT /checkout-sessions/{id}
   {
     "payment": {...},
     "fulfillment": {...}
   }
   → Updated checkout
   

4. Complete checkout

   POST /checkout-sessions/{id}/complete
   → Order created
   

5. Check order status

   GET /orders/{id}
   → Order details with fulfillment status
   

ucp.NET/
├── src/
│   └── UCP.NET/              # UCP Protocol Library
│       ├── Models/           # All UCP data models
│       ├── Client/           # HTTP client (for calling other UCP APIs)
│       └── Configuration/    # Configuration options
└── template/
    └── UCP.API/             # Your API Implementation
        ├── Controllers/
        │   ├── CheckoutController.cs   # Checkout endpoints
        │   ├── OrderController.cs      # Order endpoints
        │   └── DiscoveryController.cs  # UCP discovery
        ├── Program.cs                  # App configuration
        └── appsettings.json            # Your settings

• UCP Protocol: https://ucp.dev/
• UCP Specification: https://github.com/Universal-Commerce-Protocol
• Python SDK: https://github.com/Universal-Commerce-Protocol/python-sdk
• Sample Implementations: https://github.com/Universal-Commerce-Protocol/samples

Apache License 2.0

Build UCP-compliant commerce APIs for the future! 🚀