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@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 nd 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. 👇🏻🧵
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 nd 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. 👇🏻🧵
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Agents, meet retail.
Agents, meet business agents. A2A party.
Shopify comes with all the UCP batteries included.
Agents, meet business agents. A2A party.
Shopify comes with all the UCP batteries included.
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 demo combining Shopify catalog data with Apple MapKit APIs.
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And we're not done, more goodies on the way.
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:
webmcp.com/#shopify
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Ilya Grigorik retweeted
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.
1. a 3D globe stockist locator
2. an actual house you can explore and shop
People are going wild with this.
When we launched Canvas, I said I couldn't wait to see what everyone would make. Wow, did they deliver.
More than 2,500 Canvas stores are already live. Here are a few of my favourites, with links in the thread.
shopify.com/editions/fall2…
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Ilya Grigorik retweeted
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.
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Ilya Grigorik retweeted
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:
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:
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Ilya Grigorik retweeted
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 shop.dev, and on shop.md made what is now my favourite markdown editor.
Publish a skill to see my favourite Easter egg.
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 shop.dev, and on shop.md made what is now my favourite markdown editor.
Publish a skill to see my favourite Easter egg.
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 4Nq!
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.
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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 4Nq!
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.
Silly? Yes. Necessary? No. Fun? Abso-yes-lutely. 😆
But really, try the playground 4Nq!
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.
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Ilya Grigorik retweeted
All the tools we used to create this skill are open to devs at shop.dev
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Ilya Grigorik retweeted
Turn any existing Agent into the world's best personal shopper for you.
The new shop skill: shop.md
Add the skill & connect your Shop account & finally find the thing that you always wanted
The new shop skill: shop.md
Add the skill & connect your Shop account & finally find the thing that you always wanted
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Behind the curtain: we upgraded UCP to offer rich media (video, 3D models, and whatever else you want to bring). Live on Shopify Catalog! 🎉
PR: github.com/Universal-Comm…
PR: github.com/Universal-Comm…
PSA: The Shopify global catalog MCP now supports searching and returning products with 3D models. One of my favorite new features we’ve launched. So many fun commerce applications now possible. 🛋️
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Ilya Grigorik retweeted
Shopify merchants are live in @Meta Muse! 🎉 I've had early access and it's just so good. Well built and awesome for shopping. Leveraging Shopify's Catalog, UCP, and Shop Pay.
Meta just launched a brand new app. Muse.
Here's what matters if you're a founder: Shopify merchants are already discoverable. If your products are in Shopify Catalog and shipping to the US? You're in.
Muse didn't exist yesterday. Today our merchants can already sell through ge of building on @Shopify in the agentic era.
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Agentic commerce comes batteries included on @Shopify, with frontier capabilities. Your move, agents.
I'm happy to announce that all Shopify storefronts now support UCP 2026-08. The team worked hard to get this shipped quickly. 🎉 More to come!
Make sure to update the Shopify ucp-cli to v0.8.0 which now defaults to 2026-08.
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Ilya Grigorik retweeted
UCP, the universal commerce protocol is growing better and better shopify.com/ucp/2026-08
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🎉 UCP 2026-08 release is out. MASSIVE upgrade.
👉🏻 shopify.com/ucp/2026-08/
Agents can prove their identity and negotiate identity providers for the buyer; read the terms that govern a purchase down to the individual line item; split a payment across instruments (e.g. gift g the checkout; negotiate payment terms and schedules (due now vs. later); find nearby physical stores that carry what they need; transact in any unit (each, weight, length, whatever); navigate a 3DS challenge with new action primitives; use and build cart permalinks that can travel anywhere a URL can go (QR codes, email, chat), ..., and SO. MUCH. MORE.
88 improvements. 40 contributors. 21 weeks.
Agents: time to cook!
👉🏻 shopify.com/ucp/2026-08/
Agents can prove their identity and negotiate identity providers for the buyer; read the terms that govern a purchase down to the individual line item; split a payment across instruments (e.g. gift g the checkout; negotiate payment terms and schedules (due now vs. later); find nearby physical stores that carry what they need; transact in any unit (each, weight, length, whatever); navigate a 3DS challenge with new action primitives; use and build cart permalinks that can travel anywhere a URL can go (QR codes, email, chat), ..., and SO. MUCH. MORE.
88 improvements. 40 contributors. 21 weeks.
Agents: time to cook!
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Need a fast start for UCP? Install the UCP CLI+skill:
$> npm install -g @shopify/ucp-cli
$> ucp skills add
Boot up your agent and ask it to search for products, or build a cart/checkout. Yes, that simple.
See: github.com/Shopify/ucp-cli
$> npm install -g @shopify/ucp-cli
$> ucp skills add
Boot up your agent and ask it to search for products, or build a cart/checkout. Yes, that simple.
See: github.com/Shopify/ucp-cli
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Ilya Grigorik retweeted
I built a shopping agent inside iMessage. Open sourcing the code: github.com/gil--/ucp-agen…
1. Send a msg or photo.
2. It searches Shopify’s global catalog.
3. Builds one cart per merchant.
4. Connects Shop identity w/ budget.
5. No cc details exposed.
Why Shopify? Shop identity already covers hundreds of millions of buyers.
One protocol (UCP), every merchant. Millions of products. No scraping or “computer use”is necessary. 💚
1. Send a msg or photo.
2. It searches Shopify’s global catalog.
3. Builds one cart per merchant.
4. Connects Shop identity w/ budget.
5. No cc details exposed.
Why Shopify? Shop identity already covers hundreds of millions of buyers.
One protocol (UCP), every merchant. Millions of products. No scraping or “computer use”is necessary. 💚
Instinct shows how far LLM computer use has come but it’s still awfully slow 😴 and no one wants to share payment (or address) credentials with a 3p. 😱
Here’s a short demo of my agent, Concierge using Shopify’s UCP tools and our Shop identity tokens to directly checkout with you’re building in this space, let’s work together to enable seamless agentic commerce.
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Shipped AgentBoard 0.9, huge upgrade.
👉 github.com/igrigorik/Agen…
You can now mount a local workspace that will auto load your AGENTS.md, IDENTITY.md, etc. Better yet, it unlocks read+write support for MEMORY.md — the agent can save and retrieve context across threads, and in markdown on your device.
h/t @tobi for the workspace nudge, huge unlock.
p.s. bonus: did you know that millions of Shopify storefronts ship 🪄 WebMCP tools for catalog + cart? Makes a *huge* difference in speed and quality of agents assisting the user on the storefront.
👉 github.com/igrigorik/Agen…
You can now mount a local workspace that will auto load your AGENTS.md, IDENTITY.md, etc. Better yet, it unlocks read+write support for MEMORY.md — the agent can save and retrieve context across threads, and in markdown on your device.
h/t @tobi for the workspace nudge, huge unlock.
p.s. bonus: did you know that millions of Shopify storefronts ship 🪄 WebMCP tools for catalog + cart? Makes a *huge* difference in speed and quality of agents assisting the user on the storefront.
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