What are ChatGPT plugin extensions, and do I need one?

Should my ChatGPT plugin use extensions?

If people work in your tool for a while, probably yes. A sidebar app or a panel is the cheapest upgrade in ChatGPT right now, and almost no one has built one: only 206 of the 8,038 plugins in ChatGPT's directory (2.6%) use extensions so far.

Some context: OpenAI announced extensions at DevDay on September 29, 2026, with Figma and Adobe on stage. In OpenAI's words, they let developers "hook their plugins into key surfaces" of ChatGPT, "including the sidebar, composer, and file viewers" (extensions docs).

What can an extension do for my plugin?

Normally your widget only appears when ChatGPT decides to call one of your tools. Extensions add doors the user can open directly, so your plugin gets its own place in ChatGPT.

OpenAI lists 11 extensions. Four change where your plugin lives: sidebar apps, conversation panels, file viewers and editors, and display modes. The rest add finish, such as settings, deep links and composer mentions.

Instacart (sidebar app)Figma (sidebar and conversation)Adobe (conversation entry)

These are ChatGPT-only. They build on MCP Apps, the widget standard, but a Claude connector doesn't get a sidebar from them.

Who has built an extension so far?

Mostly creative and work tools. Instacart is the rare consumer brand.

The sidebar apps read like a home screen. monday.com's tool will "Open the full monday.com web app in the ChatGPT sidebar," and Instacart's panel holds the cart. Adobe registers .pdf for an "Acrobat side-panel viewer." 143 plugins have both a sidebar app and a panel.

At the top of the directory, 6 of the top 100 have one: Atlassian (#5), Shopify (#23), Canva (#32), Floot (#48), monday.com (#54) and Higgsfield (#79).

Which kinds of plugins use extensions?

Plugins people spend time in. Creative plugins use extensions most, at 7.7%. Travel and entertainment use them least, even though most of their plugins have a widget.

A hotel search is one question, one map and a booking. A design, a project board or a video edit is a session, and a session wants a home. The creative group is full of image and video tools (Higgsfield, Runway, Krea, fal), where a library of past work in the sidebar is an obvious win.

So, what should you do?

If people work in your tool, build a sidebar app now. Design, project management and commerce back offices fit best, as Canva, monday.com, Atlassian and Shopify show. If you already have a widget, it is a few lines of metadata on a tool you already ship.

If you're a consumer brand with a repeat job, add a panel. Groceries or a training plan need a place for the thing users keep open, like Instacart's cart.

If your plugin gives one-shot answers, skip it for now. For a hotel search or a store locator, get the tools and the widget right first.

Think of it as a retention feature. ChatGPT ranks plugins on conversion, active usage and retention (more in what top-ranked connectors have in common), and a sidebar entry keeps your plugin one click away in every new chat. If you build for Claude too, keep your core in standard MCP Apps and treat extensions as a layer on top.

Methodology

We read the ChatGPT plugin directory every day, including each plugin's tools and widget templates. All numbers are from October 20, 2026, for active plugins. A plugin counts as having an extension entrypoint if an active tool declares openai/ui entrypoints. Composer mentions and other server-level extensions aren't visible to us, so we can't count them. More on our methodology page.