Plugin extensions: sidebars, @mentions and file viewers in ChatGPT
Plugins for ChatGPT can now include interactive extensions: they can open from the sidebar, support @mentions, add viewers or editors for file types, and show forms next to the chat. OpenAI Developers published a walkthrough showing how to build one.
Why it matters
Plugins can now be small apps that sit beside the conversation, not just tools ChatGPT calls behind the scenes.
Who it's for
Developers building ChatGPT plugins, and teams that want a custom panel for their own data.
How to try it
- Watch the walkthrough linked from the OpenAI Developers post.
- Add a sidebar view or file viewer to your plugin.
- Test @mentioning it in a chat and selecting what ChatGPT should use.
Plan & availability: ChatGPT and Codex plugins; account connections and workspace permissions still apply.
Source: @OpenAIDevs on X ↗
Written by AgentStackList from the original post. Checked Oct 17, 2026. Features, plans and availability can change, so confirm on the source before you rely on it.
pluginsdeveloperschatgpt
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