This is a submission for the Google Cloud NEXT Writing Challenge
I've been watching the Google Cloud Next 2026 sessions for the past few days and there has been really exciting stuff that caught my eye. Of course, the agentic data cloud and more personally agentic commerce. Mostly because I like shopping and some websites are really taking the creativity too far with their sites. Have you tried to navigate a Zara website? It's just so confusing.
So if I can get an agent to just place the order for me. Yay to that!
What agentic commerce means
AI shopping has been a buzzword for years. The agent could recommend a product, but you still had to navigate to the website, add it to cart, and click Buy. What's changing now is that agents can complete a purchase autonomously, on your behalf, without your input at every step.
That shift from advisory to transactional changes everything architecturally. An agent that recommends products needs good search and ranking. An agent that buys products needs:
- A standard way to discover what a merchant sells
- A standard way to query inventory in real time
- A standard way to initiate and complete checkout
- A cryptographically verifiable way to prove the user actually authorized the purchase None of that existed in a standardized form before. UCP and AP2 are the attempt to build it.
The Universal Commerce Protocol (UCP)
UCP is an open-source standard built by Google in collaboration with Shopify, Etsy, Wayfair, Target, and Walmart.
A merchant exposes a .well-known/ucp discovery endpoint, and any agent can call it to understand what that merchant supports.
Here’s an example:
curl -X GET https://yourstore.com/.well-known/ucp
{
"ucp": {
"version": "2026-01-11",
"services": {
"dev.ucp.shopping": {
"version": "2026-01-11",
"rest": {
"endpoint": "https://yourstore.com/ucp/"
}
}
},
"capabilities": [
{ "name": "dev.ucp.shopping.checkout" },
{ "name": "dev.ucp.shopping.discount" },
{ "name": "dev.ucp.shopping.fulfillment" }
]
}
}
From there, a shopping agent can create a checkout session, apply discounts, verify inventory, and complete a purchase all through standardized primitives that map 1:1 to standard retail operations.
This protocol is designed for interoperability across the entire agentic commerce ecosystem.
It’s compatible with:
- MCP (Model Context Protocol) so agents can discover and call UCP endpoints as tools
- A2A (Agent-to-Agent) so a personal shopping agent can negotiate with a merchant's agent directly
- AP2 (Agent Payments Protocol) for the actual authorization and settlement of the transaction
How does an Agent prove you authorized it?
When a human completes a purchase, there's an implicit chain of consent. You clicked Add to Cart, you entered your payment details, you clicked Buy. Each step is evidence of human intent.
When an agent completes a purchase, that chain doesn't exist in the same way. So how does a merchant or a payment processor know that the user actually authorized this specific purchase, at this price, at this moment?
The AP2 (Agent Payments Protocol) is designed to solve this by establishing a cryptographic credential that travels with the transaction, tying it back to a specific, scoped user consent.
Think of it like OAuth for purchasing authority. Just as OAuth lets you grant an app specific permissions (read my calendar, but not write to it), AP2 is designed to let users grant agents specific purchasing authority (buy items under $50, but ask me before anything larger).
Without it, agentic commerce creates an unacceptable fraud surface. If any agent can claim to represent any user, you'd need to either lock down agent transactions entirely or accept massive fraud risk.
What agentic commerce looks like for users
You tell your agent you want that linen blazer you saw on Instagram. The agent queries Zara's UCP endpoint, finds the right size, confirms it's in stock, applies your loyalty discount, and completes the purchase via Google Pay all inside a single conversation, without you ever loading a page. You remain the customer and the store remains the Merchant of Record.
They own the customer relationship and the post-purchase experience. They're not handing their customer to Google but just making their checkout accessible to any agent that speaks UCP. The agent could be Gemini. It could be someone's personal AI assistant. It could be a third-party shopping agent on a completely different platform.
What it means for developers
Most developer work in commerce today is optimising for human behaviour. We strive for faster page loads, better search UX, smoother checkout flows, retargeting pixels, A/B testing button colours. All of that assumes a human is navigating. If UCP becomes the standard and agents autonomously shop for us, huge swaths of that work become irrelevant. The new optimisation surface is your API response time and even more so your data quality, not your UI.
Your catalog needs to be complete, products need accurate attributes, and even functions like promotions or discounts need to be queryable.
The UCP protocol is open source. You can see implementation examples and start experimenting with the SDKs.
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