Ilya Grigorik

Distinguished Engineer, @Shopify. On a mission to make commerce better for everyone.

[Ilya Grigorik @igrigorik]

@tobi and I sat down to talk UCP and the art of protocol design. A couple of themes worth expanding on...

The hard part of good protocol design isn't the spec. It's the deep understanding of the problem you're solving and the humility to approach it at the right level. Commerce is infinitely complex and always evolving; it's hubris to pretend anyone can 'spec commerce'.

But wait — isn't UCP trying to do exactly that?

No, UCP doesn't 'spec commerce'. It models the rules of the bazaar that make commerce possible. The job of UCP is to build the boring parts: the small core of common and composable primitives, and the discovery and negotiation mechanisms that everything else runs on. Done right, this lets commerce thrive in the open, with merchants, agents, and buyers deciding what is advertised, supported, and adopted, not by fiat from a protocol committee. This is UCP. 👇🏻🧵

[Ilya Grigorik @igrigorik]

@init_adam Love it! Do you have your build on GitHub? Would love to see if we can bring some of this back into AgentBoard.

[Ilya Grigorik @igrigorik]

@VivaLLCnet That's why UCP offers catalog API access: structured data, realtime, authoritative. Stop scraping, start using right tools for job!

[Ilya Grigorik @igrigorik]

Agents, meet retail.
Agents, meet business agents. A2A party.

Shopify comes with all the UCP batteries included.

[Gil @gilgNYC]

I want to highlight 4 features Shopify launched on UCP (universal commerce protocol) that enables richer experiences in agentic commerce:

1. UCP’s location capability is now supported on the Storefront MCP enabling buyers to understand nearby physical locations and if products are available. Here’s a demo combining Shopify catalog data with Apple MapKit APIs.

[Ilya Grigorik @igrigorik]

@openfort_hq Spend caps are available on Shop Pay. Authorize the agent and then assign a budget for it on https://t.co/k1yFXvj0yO. And UCP already solves payments for commerce (see payment handlers); x402 is great but not appropriate tool for the job in this case.

[Ilya Grigorik @igrigorik]

And we're not done, more goodies on the way.

[idan levin @0xidanlevin]

Shopify is (almost) the only place on the internet that has implemented WebMCP end-to-end

Which means that on Shopify sites you can go from search -> cart -> checkout and complete a purchase entirely through WebMCP tools

We’ve indexed >2.3 million of this sites, learn more about the Shopify WebMCP implementation here:

https://t.co/WDp3CQTIB3

[Ilya Grigorik @igrigorik]

@0xidanlevin Or just use Shopify. Vitamins included.

[Ben Sehl @benjaminsehl]

No one could say it better than the 🐐 storyteller. Canvas is now rolled out to 100% of merchants and the impact is crazy -- two more of my favorites:

1. a 3D globe stockist locator
2. an actual house you can explore and shop

People are going wild with this.

[Ilya Grigorik @igrigorik]

Great look requires great engineering.

Although perhaps the even harder part was negotiating which shipped features we leave out.

[Arnaud Tanielian @Danetag]

We just launched Shopify Editions Fall 2026 🍁

Here's the technical breakdown of how we built it 🧵

[tobi lutke @tobi]

Look for Expo Mode. We built it with Google’s new HTML-in-Canvas API. I think we’re one of the first to use it.

[David Cortés @davebcn87]

River, our Slack bot at Shopify, wasn't good at building mobile apps at first.

We fixed that, but engineers were still skeptical. Mobile development has always happened on your laptop, right?

So I made a series of internal ads for it. This is one of those:

[Ilya Grigorik @igrigorik]

@MartinLasmanis The agent creates the request and buyer approves, if the total does not match when submitted by the agent.. yes, it may be declined and user has to re-approve. The agent can also update the request if it knows upfront that there will be a mismatch.

[Ilya Grigorik @igrigorik]

Yo dawg, heard you like MCP. So we compiled the shop CLI (an MCP client) to WASM, put it in a browser terminal, and exposed it over #WebMCP, so your agent can call MCP tools that call MCP tools.

Silly? Yes. Necessary? No. Fun? Abso-yes-lutely. 😆

But really, try the playground on https://t.co/wlvCiAQ4Nq!

1B+ products from millions of Shopify stores, cart → checkout → Shop Pay, order tracking. Bonus, try `shop spend-request`: buyer approves in Shop, your agent gets a single-use payment credential, and checks out anywhere on the web.

$> npm install --global @shopify/shop@latest
$> shop skill --install

From discovery to purchase, batteries included.

[Ilya Grigorik @igrigorik]

@deepanshuxpal exactly that.

[Ilya Grigorik @igrigorik]

@xpressoh11 It executes real, live queries, but it's a developer oriented demo.

[Ilya Grigorik @igrigorik]

@ecomattache @tobi @ecomattache updated logic is live -- no client update required. `shop order search` should now show recent+active+client-own orders.

[Ilya Grigorik @igrigorik]

@ecomattache @tobi Hold that thought... the stove is on, let me check on it.

[Ilya Grigorik @igrigorik]

@Avery_Jones don't tempt me

[Ilya Grigorik @igrigorik]

@ecomattache @tobi You're not missing anything. The default behavior is that the app/client can see its *own* past orders.

[Ilya Grigorik @igrigorik]

@jmwind Yep! That's exactly what MCP+CLI input schema & skill teach the agent to do. Agent maps intent/prose to structured args across both.

[Ben Sehl @benjaminsehl]

We made a good version of both of these within a day … and then we were like “but what if…” over and over again.

Working with @igrigorik and @suprb on this was so fun that I laughed basically every day out of disbelief from how ridiculous we were making it.

We pushed these marketing sites to the limit, and then kept pushing.

Built a full terminal in the browser (you can mkdir/echo/cd/whatever) on https://t.co/5a69JrQ2Wd, and on shop.md made what is now my favourite markdown editor.

Publish a skill to see my favourite Easter egg.

[Ilya Grigorik @igrigorik]

@KeithZhai Yes. We bundle schema and skill in the CLI itself, so webmcp bootstraps from `shop [tool] --schema`.