> You type in what you are looking for, "linen shirt under $80" or "running shoes for wet trails", and it searches across every UCP-connected merchant in real time.

I expect scaling problems to crop up very quickly.

It will be a scaling problem for the search engine: How do you query every merchant in real time when the number of merchants increases by 10X?

And for the merchants: How do you handle the increased load when the number of queries increases by 10X or 100X?

At some point, the merchant is going to look at their logs and wonder why 99% of the search queries they're receiving are for products that aren't even in their retail category.

> Think of it as what RSS did for blogs, but for buying things.

RSS was a nice standard for subscribing to feeds, but it and this UCP standard have fundamentally different access patterns.

With RSS, you basically accessed your feeds like you accessed your webpages.

But with UCP, the pitch is real-time search across an unlimited number of sites, with no indexing. If that approach were scalable, Google would have already done it.

UPDATE: After reading through https://ucp.dev it looks like Google and Shopify have co-developed the protocol. So I suspect that either there's some Google magic happening under the hood, or the "searches across every UCP-connected merchant in real time" claim in the blog post is not accurately describing the underlying architecture.

Looks interesting. I was somewhat skeptical, but it appears to be a legitimate open protocol. You can use it to build a search engine for products across many smaller stores, and facilitate ordering from within your app, which appears to be what Google Shopping and the above website are both doing. Sort of a decentralized Amazon MFN.

It's also designed to be used by AI agents. This should enable any AI agent to discover products and purchase items from any UCP-enabled store, in a safe way.

Here's the spec: https://ucp.dev/latest/specification/overview/

Every Shopify store appears to already support it. Example: https://shop.spacex.com/.well-known/ucp

I’m building something similar[0] but based on MCP-UI instead of UCP since Google and Shopify controlling UCP makes me feel like they will gate keep stores or start rent seeking eventually.

Alongside the interoperable marketplace, I’m also building an open source alternative to Shopify, Toast, etc[1] along side this marketplace.

0. https://marketplace.openship.org 1. https://openship.org

> Without something like UCP, you are stuck doing [...] crawling.

I don't work in the area, but isn't this by design? Of course shops want to be discoverable by Google, but stopping competities from crawling and undercutting them is also very important.

Maybe this is different now that Amazon is the gatekeeper which can (ab)use this information anyway, and the incentive for shops to enable competing marketplaces is greater than frustrating competitors

Yahoo was the front door of the Internet, once.

Getting stores to adopt this is unlikely, unless you get the European Union to mandate it or something like that. But using a crawler to find items for sale and an LLM to interpret the item listing might work. Then resell the processed pricing info. Publicize by using it for inflation calculations and such.

One of the main benefits other than this is that you can more reliably find higher quality hand made crafts over the main alternative of etsy. Searching up "Handmade leather bound books" pulls up more 'trustworthy' results compared to having to scope out constant dropshipping scams.

This looks cool but when I try to use it and push Open on a product it takes me to checkout. What I wanted was to see product details.

Intriguing. Is this UCP supported at any of the marketplace platforms like shopify? Where did it originate?

I really can't stand this style of writing anymore, this quick succession of "impactful" short sentences, some of them without even a verb. I don't know if I just started noticing them recently or if it was always like common, but I hate it.

Why would shops implement this. It would detrimental to them if customers could easily find the cheapest option.