Universal Commerce Protocol (UCP) Samples

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

Sample Implementations

Python

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

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.

A2A (Agent-to-Agent)

An AI-powered retail agent implementing UCP via the A2A protocol.

• Cymbal Retail Agent: Documentation
  • Located in a2a/business_agent/.
  • Demonstrates A2A protocol integration with UCP Extension.
  • Includes AI-powered shopping assistant with Google ADK and Gemini.
  • React-based chat client for user interaction.

Getting Started

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