UCP
ReadyUniversal Commerce Protocol — Google + Shopify
Overview
UCP (Universal Commerce Protocol) is a joint initiative by Google and Shopify to create a standardized commerce layer for AI agents. It defines how agents discover products, compare prices, negotiate terms, and complete purchases across any merchant — essentially building a universal checkout for the AI economy.
How It Works
UCP defines three phases of an agent commerce transaction: Discovery (the agent queries a UCP-compatible catalog for products/services matching criteria), Negotiation (the agent and merchant exchange offers, counteroffers, and terms using structured UCP messages), and Settlement (the agent commits to a purchase and the payment is processed through the merchant's payment provider).
For AI tool monetization, the "product" is a tool invocation. The agent discovers available tools via UCP catalogs, checks pricing and terms, and initiates a purchase (invocation) using the UCP settlement flow. This creates a catalog-native experience where agents can shop for the best tool at the best price.
UCP supports dynamic pricing, bulk discounts, and subscription models — giving developers more flexibility than simple per-call billing.
How SettleGrid Integrates
SettleGrid exposes your tool as a UCP-compatible service. When a UCP agent discovers your tool in the catalog, SettleGrid returns your pricing, terms, and availability. When the agent initiates a purchase, SettleGrid handles the settlement flow, meters the invocation, and records the transaction. Developers get UCP catalog visibility without building any UCP-specific infrastructure.
Key Specs
| Protocol | UCP — Universal Commerce Protocol |
| Backer | Google + Shopify |
| Detection Header | X-UCP-Session / Authorization: UCP <session> |
| Identity Type | ucp-session |
| Payment Type | ucp-settlement |
| Status | Ready |
Code Example
Here is how a developer's tool works with UCP via SettleGrid:
import { settlegrid } from '@settlegrid/mcp'
const sg = settlegrid.init({
toolSlug: 'product-research',
pricing: {
defaultCostCents: 8,
methods: {
'search': { costCents: 3 },
'compare': { costCents: 8 },
'deep-analysis': { costCents: 20 },
},
},
// UCP sessions are managed automatically
})
const compare = sg.wrap(async (args: { products: string[] }) => {
const comparison = await compareProducts(args.products)
return { content: [{ type: 'text', text: JSON.stringify(comparison) }] }
}, { method: 'compare' })Start monetizing with SettleGrid
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