Who's already inside ChatGPT, Claude and Copilot

Someone opens ChatGPT and types "find me a three-bedroom house near a good school". Instead of ten blue links, Zillow listings appear right in the chat, with photos and a map. They ask a follow-up. They ask about a tour, and the app sends them to Zillow to book it.

That has been possible since October 2025. Since then, dozens of well-known companies have built apps that run inside ChatGPT, Claude and Microsoft Copilot. This post walks through who went first, what they built, how the shopping experiment turned out, and what it means if you run a business with a product people already use.

A quick note on names. OpenAI called these "apps" at launch, then renamed its app directory the "Plugin directory" on 9 July 2026, according to OpenAI's Help Center. Claude calls them "connectors". Under the hood nearly all of them use the same open standard, MCP (the Model Context Protocol), so one well-built app can serve several assistants.

The timeline, 2024 to 2026

Here's the order things happened in, from the companies' own posts and the press coverage that reported them. Where we could only see a claim in news coverage, the source column says so.

Two things jump out. First, Claude and Copilot started with work tools: issue trackers, payments dashboards, design files. ChatGPT's first wave was consumer brands: music, homes, travel, groceries. Second, the same names keep showing up. Figma is in all three assistants. Canva is in ChatGPT and Claude. Coursera is in ChatGPT and Copilot, and monday.com is in Claude and Copilot. These companies built on MCP and showed up in several places.

The audience is not small. Sam Altman said ChatGPT has 1.2 billion weekly users at DevDay on 29 September 2026, as reported by Engadget. As of 17 October 2026, Claude's directory page shows 973 connectors.

What these apps actually let people do

Strip away the launch posts and most of these apps do one or two jobs well. Here's what each one lets a person do in the chat, and what kind of tool it is underneath.

Notice what's missing. None of these descriptions is "everything our website does". Spotify's is finding music by mood. Zillow's is finding a home and reaching an agent. Each company picked a question people already ask and built for that.

The checkout experiment

Commerce is where the story gets interesting, because it's the one place we have a real number.

In September 2025, OpenAI launched Instant Checkout and the Agentic Commerce Protocol, built with Stripe. Etsy sellers came first, with Shopify merchants such as Glossier, SKIMS, Spanx and Vuori "coming soon", as reported by TechCrunch. Walmart announced its own Instant Checkout deal on 14 October 2025, reported by Dallas Innovates. On 8 December 2025, Instacart became the first company to offer Instant Checkout inside a ChatGPT app.

Then came March 2026. Walmart's Daniel Danker told WIRED that checkout inside ChatGPT converted at about one-third the rate of click-throughs to Walmart.com, with about 200,000 products available, as reported by Search Engine Land. Walmart moved to a Sparky app inside ChatGPT, reported by eMarketer. On 24 March 2026, OpenAI deprioritized Instant Checkout. Merchants now use their own checkout, and the protocol is used for product discovery instead, with Target, Sephora, Nordstrom, Lowe's, Best Buy, The Home Depot and Wayfair integrated.

Here's what the companies have said about results, side by side.

Here's the honest part. Most of these brands haven't published usage or conversion numbers for their assistant apps. Walmart's one-third figure is the only hard conversion number we found, and it's about checkout inside the chat, not about the app as a whole. Treat everything else as direction, not proof.

The direction is consistent, though. People use the assistant to find and compare. When it's time to pay, they come to you. Etsy said it. Walmart's number says it. OpenAI's March change says it. And Adobe reports that in March 2026, traffic from AI tools to US retail sites converted 42% better than other traffic, with 37% higher revenue per visit, as reported by TechCrunch. The assistant is a front door. Your checkout is still the till.

The patterns worth copying

You don't need Walmart's budget to learn from Walmart's experiment. Five patterns show up across nearly every app in the tables above.

1. A few jobs, not the whole site. Spotify finds music by mood. Zillow finds homes. Slack drafts a message. Anthropic's own advice is to build a few tools around high-impact workflows rather than wrapping every endpoint (Anthropic, Writing effective tools for agents). OpenAI suggests aiming for fewer than 20 functions at the start of a turn (OpenAI function calling guide).
2. Look first, act carefully. Slack's Claude connector drafts messages that you review before they're posted. Both big directories make you say which tools only read and which change things. ChatGPT requires readOnlyHint, destructiveHint and openWorldHint to be set explicitly (OpenAI submission guidelines). Claude requires a title plus readOnlyHint or destructiveHint on every tool (Claude submission docs).
3. Hand off at the moment of commitment. Zillow passes you to an agent. DoorDash sends you to its app. Etsy sends you to Etsy to buy. The assistant does the finding; the company keeps the relationship.
4. Your sign-in, your customer's data. Stripe's Claude connector works with the customer's own payment data, and Notion's with their own roadmaps (Anthropic). Claude's directory requires OAuth 2.0 over HTTPS for any service that needs sign-in (Claude submission docs). People sign in with the account they already have with you.
5. Show, don't just tell. The interactive Claude connectors return charts, boards and file previews instead of paragraphs (Anthropic). OpenAI's design guidelines keep it tight: cards carry at most two actions, and carousels hold 3 to 8 items (OpenAI design guidelines).

Discovery versus checkout

If you sell something, this is the decision that matters most. Do you build an app that helps people find and compare, or one that takes the order?

The evidence so far points to discovery. Etsy, DoorDash and Zillow all built for discovery and handed off. Walmart and OpenAI both moved away from in-chat checkout in March 2026. That doesn't mean checkout in an assistant will never work. It means the companies with the most data stepped back from it this year, and you probably don't need to be the one who proves them wrong.

Discovery is also easier to get right. Read-only tools that search your catalogue, check availability or quote a price can't change anything by mistake. They're simpler to review. And they send people to your site at the point where they're ready to buy.

Being early still counts

Zillow's CEO made a point of calling Zillow the only real estate app inside ChatGPT, on its Q3 2025 earnings call. Expedia told investors it is live with Claude and that answer engine optimization is its fastest-growing channel (Q1 2026 call). Large companies are treating presence in assistants as a channel worth naming to shareholders.

Look back at the tables: nearly every name is a household brand. If you're a regional booking service, a specialist retailer or a B2B tool with a loyal customer base, there's a fair chance your direct competitors haven't built an app yet. Search the directories for your category and see. That window won't stay open forever.

What this means for you

• Pick two or three jobs. Look at what customers ask your support team most. "Is this in stock?" "What does the pro plan cost?" "Where's my order?" Those are your first tools.
• Start read-only. Searching, quoting and checking status are lower risk, easier to review and match what the big brands shipped first.
• Keep checkout on your site. Let the assistant find and compare, then hand people to your own checkout, where your conversion already works.
• Use the sign-in you already have. If people need an account, they should sign in with the one they already have with you.
• Build once, list in several places. Figma shows up in ChatGPT, Claude and Copilot, and all three assistants speak MCP.
• Know the limit. An app gives assistants a reliable way to do things for people who've already asked. It doesn't make an assistant recommend you, and no directory promises a listing.

Where to go from here

If you want to see what each directory asks for, start with where to list your MCP server, then read the ChatGPT and Claude guides. Turning your API into an MCP server covers the build. Transica turns your API into an app for ChatGPT, Claude and other assistants, prepares it for each directory's review, hosts it on your own domain behind your existing sign-in, and monitors it. Our agent tests run the same task on your website and in your app and report exact pass counts, so you can see the difference for yourself. Want a quick look at how AI agents see your site today? Scan a page for free, with no account.