langchain-ucp 0.1.1

LangChain toolkit for Universal Commerce Protocol (UCP)

LangChain UCP

LangChain toolkit for Universal Commerce Protocol (UCP).

Overview

langchain-ucp provides LangChain tools and toolkit for building AI agents that can interact with UCP-compliant merchants.

Installation

pip install langchain-ucp

Quick Start

from langchain_ucp import UCPToolkit, Product
from langchain_openai import ChatOpenAI
from langgraph.prebuilt import create_react_agent

# Define your product catalog (for agent-side discovery)
# Full product details come from the merchant via UCP
products = [
    Product(id="roses", title="Red Roses"),
    Product(id="tulips", title="Spring Tulips"),
    Product(id="orchid", title="White Orchid"),
]

# Create toolkit with product catalog
toolkit = UCPToolkit(
    merchant_url="http://localhost:8000",
    products=products,
)

# Create agent
llm = ChatOpenAI(model="gpt-4o")
agent = create_react_agent(llm, toolkit.get_tools())

# Run agent
result = await agent.ainvoke({
    "messages": [{"role": "user", "content": "I want to buy some red roses"}]
})

Product Catalog

The Product model is a temporary solution for agent-side discovery. It only requires the minimum fields needed for search.

Field	Type	Required	Description
id	str	Yes	Unique product identifier (must match merchant's product ID)
title	str	Yes	Product display name (used for search)

Note: When UCP product discovery is implemented, the full product catalog (pricing, categories, descriptions, images) will be fetched directly from the merchant.

Available Tools

Tool	Description
search_shopping_catalog	Search the product catalog
add_to_checkout	Add products to cart
remove_from_checkout	Remove products from cart
update_checkout	Update product quantities
get_checkout	View current cart
update_customer_details	Add buyer info and address
start_payment	Prepare checkout for payment
complete_checkout	Complete purchase
cancel_checkout	Cancel checkout
get_order	Get order details

Examples

See the examples directory for complete working examples:

• basic_agent.py - Simple agent that adds items to cart
• interactive_chat.py - Interactive chat with the shopping agent

License

Apache License 2.0