Universal Commerce Protocol (UCP) Samples

This directory contains sample implementations and client scripts for the Universal Commerce Protocol (UCP).

Sample Implementations

REST Bindings

Python (REST)

A reference implementation of a UCP Merchant Server using Python and FastAPI.

• Server: Documentation

  • Located in rest/python/server/.
  • Demonstrates capability discovery, checkout session management, payment processing, and order lifecycle.
  • Includes simulation endpoints for testing.

• Client: Happy Path Script

  • Located in rest/python/client/.
  • A script demonstrating a full "happy path" user journey (discovery -> checkout -> payment).

Node.js (REST)

A reference implementation of a UCP Merchant Server using Node.js, Hono, and Zod.

• Server: Documentation
  • Located in rest/nodejs/.
  • Demonstrates implementation of UCP specifications for shopping, checkout, and order management using a Node.js stack.

MCP Binding (Model Context Protocol)

A reference implementation using the Model Context Protocol for AI agent integration.

• Server & Client: Documentation

  • Located in mcp/python/.
  • Exposes UCP shopping capabilities as MCP tools and resources.
  • Enables AI agents (Claude, GPT, etc.) to perform commerce operations.
  • Includes example client demonstrating complete shopping flow.

Key Features:

• Tools for product discovery, checkout, payment, and order management
• Resources for read-only access to catalogs, sessions, and orders
• Prompts for reusable conversation patterns
• Support for stdio, HTTP, and SSE transports

A2A Binding (Agent-to-Agent)

An example Business A2A Agent implementing the UCP Extension.

• Agent & Client: Documentation
  • Located in a2a/.
  • Demonstrates agent-to-agent communication for commerce operations.
  • Includes chat client for interactive testing.

Protocol Binding Comparison

Binding	Use Case	Transport	Best For
REST	Traditional APIs	HTTP	Web/mobile apps, service integration
MCP	AI Agents	stdio/HTTP/SSE	LLM integration, conversational commerce
A2A	Agent Communication	HTTP	Multi-agent systems, automated workflows

Getting Started

Please refer to the specific README files linked above for detailed instructions on how to set up, run, and test each sample.