ChatGPT Plugin Extensions, Explained: What the New 'Plugin Store' Actually Is, How to Install Plugins, and What Replaces Custom GPTs

Short answer: ChatGPT now has an app layer. At DevDay on September 29, OpenAI shipped Plugin Extensions — a way for a plugin to stop being a tool the model quietly calls and become something you see: an app in the sidebar, a panel beside your chat, a viewer that opens your Figma or Photoshop files. People are calling it a 'store' or 'web extensions.' It's neither, exactly. There's a plugin directory you browse inside ChatGPT (yes, that's the 'store,' and no, nothing in it charges through OpenAI). There's a separate OpenAI Marketplace for companies. There's Sign in with ChatGPT for using your plan inside other apps. And there's a deadline that will matter to more people than any of it: Custom GPTs retire on December 11, 2026. Five products, one week, and most coverage mashes them together — so here's the glossary first.

The glossary: what people say vs what it's called

What ChatGPT Plugin Extensions are

OpenAI's developer docs put it plainly: 'OpenAI MCP Extensions enables developers to hook their plugins into key surfaces of the ChatGPT user experience, including the sidebar, composer, and file viewers.' The DevDay recap: 'We're opening the platform we use to build ChatGPT features so developers can create their own experiences within ChatGPT.' The surfaces, per the docs: sidebar apps ('open your app from the sidebar and work in it fullscreen'), conversation panels ('open your app beside a conversation'), file viewers and editors for the file types a product supports, rich forms, deep links, and composer mentions — typing @ to pull a file from, say, Figma into your prompt. The day-one examples OpenAI cites: Canva's sidebar tabs for designing inside ChatGPT, Figma file mentions, and Adobe letting you 'edit files with Acrobat and Photoshop directly in ChatGPT.' It is not a browser extension. Nothing installs in Chrome; 'web' here means chatgpt.com.

Is there a ChatGPT plugin store?

In spirit, yes: the plugin directory, shared by ChatGPT and Codex, with tabs for Public, Your workspace, Personal, and Installed, 'Popular' and 'New & Noteworthy' sections, an 'OpenAI Verified' badge for plugins OpenAI 'reviews… for quality, reliability, and usefulness,' and — new — recommendations that surface mid-conversation. In economics, no. OpenAI announced no billing, no checkout, and no revenue share for plugins. Its guidelines say plugins 'may conduct commerce only for physical goods' and 'must not apply ChatGPT-specific fees'; developers monetize through their own external checkout. TechCrunch's framing that this 'takes direct aim at the app store model' is about distribution — OpenAI's Tibo Sottiaux: 'We have over 1.2B weekly users and will surface relevant plugins right in the conversations' — not about a store you pay in.

Plugin Extensions vs the 2023 plugins vs Custom GPTs vs Marketplace

How to install a ChatGPT plugin

From OpenAI's help center: 'Go to Plugins on the sidebar on ChatGPT web, desktop or mobile.' Then:

• 1. 'Select the plugin and review its included apps.'
• 2. 'Select Install plugin if shown; installation may start the app's setup or authorization flow.'
• 3. 'If prompted, select Connect for an app that requires account authorization' — signing in 'to the intended provider account only when individual authorization is required.'
• 4. Approve only the scopes the prompt asks for. Permission levels are Always ask, Allow read actions, Allow low-risk actions, or Allow all actions (which OpenAI itself labels as carrying 'elevated risk').
• 5. Use it. 'ChatGPT automatically uses your installed plugins when they're relevant to your request. You can also select a plugin directly with an @ mention.' Sidebar apps open 'by selecting their icon in the ChatGPT sidebar.'
• 6. Use the desktop app for the full experience. File mentions, file opening, and composer @-mentions are desktop-only per OpenAI's compatibility table; plugins marked 'Desktop only' 'can't run in ChatGPT on the web.'

Which plan gets what — and why plugins might not be showing

• The directory is on every plan. 'The plugin directory is available across ChatGPT plans. Installing or using an individual plugin depends on your plan, workspace, role, region, and its included capabilities.'
• Extensions on the web aren't on Free or Go yet. Verbatim from the docs: 'Plugin extensions on the web are coming soon to ChatGPT Free and Go users. Existing plugin functionality is unaffected.' If you're on Free and the Canva sidebar isn't there, this is why.
• Some things are desktop-only. Composer mentions 'are available only in the ChatGPT desktop app.' Look for the 'Desktop only' label in the directory.
• It's rolling out. OpenAI's help pages carry a banner: 'We're gradually rolling out new features announced at DevDay. Some features may not be available to your account yet.'
• Work accounts may need an admin. In Enterprise workspaces, uploading plugins and creating plugins with MCP are off by default; admins turn them on. FedRAMP workspaces where Plugins is unavailable use Apps instead.
• Are plugins free? Browsing and installing costs nothing beyond your plan. A plugin may require a paid account with the third party (Canva, Figma). OpenAI publishes no install price and, for Enterprise, notes that creating plugins through conversation 'use[s] Work or Codex' and 'actions in Work consume credits.'

Custom GPTs are going away — migrate before December 11

This is the part that will matter to the most people. From OpenAI's retirement FAQ: 'Custom GPTs are scheduled to retire on Dec 11, 2026. For affected Enterprise workspaces with an approved deferral, the retirement date is Feb 11, 2027.' At that date 'custom GPTs and their GPT pages become inaccessible.' Creation of new GPTs is already off for personal accounts — Free, Go, Plus, and Pro — and for workspaces the planned cutoff is October 26, 2026, a date OpenAI marks 'planned' under a header that says 'the dates are subject to change.' (Older caches show a September 25 freeze; the live page has moved it.)

• If you built a GPT people use: publish the latest version, migrate, rebuild any Actions, test it with an @-mention, then re-share — old GPT share links die with the GPT.
• If you just use someone's GPT: ask the creator whether they've migrated. After December 11 the link stops working.
• Is the GPT Store closing? OpenAI hasn't used those words; it says GPT pages 'become inaccessible.' In practice that's the same thing for you.

Sign in with ChatGPT and OpenAI Marketplace — the other two things launched

Sign in with ChatGPT lets you log into other apps with your ChatGPT account — and, if you're on Plus or Pro, spend your plan's usage inside them. OpenAI: 'Use your allowance across 16 partners including Cognition's Devin, Notion, Vercel, T3, OpenClaw, and Dactyl, and control how much each can use.' Identity works globally; plan usage is Plus and Pro only, with a weekly cap you set per app. What the app gets: 'your name, email address, and profile picture' — 'not… your ChatGPT conversations or memories,' and no API key. Commercial partners are in 'a limited trial.'

OpenAI Marketplace is for companies, not you: 'Eligible enterprise customers can apply part of their existing OpenAI commitment toward approved partner software.' The 32 launch partners include Figma, Adobe, Salesforce, HubSpot, ServiceNow, Harvey, Legora, CrowdStrike, and Palo Alto Networks; 'you contract with and pay the partner directly; OpenAI reconciles use of your commitment.' It's the same idea Anthropic launched in March and rebuilt last week as Claude Marketplace — and several vendors (Harvey, Legora, Vercel) are on both.

For developers: shipping into 1.2 billion weekly users

• Stand up an MCP server. Extensions work with the November 2025 or July 2026 MCP versions; the docs link the spec. MCP Events — letting ChatGPT subscribe to your server and act on updates — needs the July 2026 version ('MCP 2.0') plus webhook delivery; polling and streaming aren't supported.
• Add the extensions SDK: @openai/mcp-extensions for TypeScript or openai-mcp-extensions for Python, both Apache-licensed on GitHub. OpenAI's Max Stoiber: it's 'the same plugins platform we use to build features internally.'
• Declare your surfaces — sidebar, panel, file handlers — and note the compatibility table: file features and composer mentions are desktop-only at launch.
• Test in Developer mode, then submit. The directory has a redesigned review flow; you choose when to publish, and OpenAI 'scans your hosted MCP server daily' for changes. Submission requires individual or business verification. No listing fee is mentioned.
• Or skip the code: Plugin Creator is itself a plugin — 'start a chat with @plugin-creator and describe what you want to build.' Available on all plans, with admin permissions needed in managed workspaces.
• Reality check on 1.2B: that's OpenAI's 'collective' weekly figure across products. Being listed isn't being recommended, and the ranking rules for in-conversation suggestions are new and thinly documented.

Are ChatGPT plugins safe?

Safer by design than most app ecosystems, with two things to watch. You approve each plugin's access, and a plugin 'cannot use an app to access content outside the permissions granted' to your account — installing one 'cannot bypass provider or workspace permissions.' Plugin interfaces run 'inside an isolated iframe with a strict Content Security Policy,' and ChatGPT 'will never directly provide raw filesystem paths' to them. Watch item one: a connected app 'may access and use relevant context from your ChatGPT conversations' and, with Memory on, 'relevant information from memories' — so a plugin can see more than the file you hand it. Watch item two: on Free, Go, Plus, and Pro, 'OpenAI may use information accessed from apps to train our models if your Improve the model for everyone setting is on' — here's how to turn it off. Business and Enterprise data isn't used by default. Don't grant 'Allow all actions' to anything, and don't confuse this with Dots — an always-on agent holding your logins is a different product with a different risk profile, even though it uses the same plugins.

Quick answers

• What are ChatGPT Plugin Extensions? Apps that run inside ChatGPT — in the sidebar, a panel next to the chat, or a file viewer — instead of only being a tool the model calls.
• Is there a ChatGPT plugin store? A plugin directory shared by ChatGPT and Codex, yes. A store you pay in, no. OpenAI Marketplace is for enterprises.
• Is this a Chrome extension? No. It's plugin interfaces on chatgpt.com and in the desktop app; Free and Go web support is still coming.
• Are plugins free? No fee from OpenAI. Some plugins need a paid ChatGPT plan or a paid third-party account.
• Where did the 2023 plugins go? Wound down in spring 2024 in favor of GPTs. This system is MCP-based and is not that store coming back.
• What happens to my Custom GPTs? They stop working December 11, 2026 (February 11, 2027 for Enterprise workspaces with an approved deferral). Migrate from My GPTs; Custom Actions don't come with you.
• Plugins not showing? Free or Go on the web (extensions coming soon), a 'Desktop only' plugin on the web, a workspace admin who hasn't enabled plugins, or the gradual rollout.

What's next, and our read

Coming, per OpenAI: web extensions for Free and Go, more Sign in with ChatGPT partners (Lovable is listed as 'coming soon'), and more plugins adding event support. Unannounced, and worth watching: any payment layer, which would turn the directory into an actual store. Our read: OpenAI just did to ChatGPT what Apple did to the iPhone in 2008 — with one deliberate omission. There's a directory, a review badge, an SDK, and 1.2 billion weekly users, but no 30% cut and no consumer checkout, which means the pitch to developers is distribution, not revenue. The smartest move in the package is the least glamorous one: retiring Custom GPTs on a date and offering a one-click migration, so the millions of half-built GPTs become plugins that can actually appear in a conversation. If you have a GPT, that's your to-do list. If you're a developer, Canva got a sidebar tab in ChatGPT before most companies knew this existed — that's the window. Our ChatGPT review now covers the plugin layer.