On September 29, OpenAI announced at DevDay 2026 that it is turning ChatGPT into an open app platform: plugin extensions are now available to users on all plans, subscription allowances can be used directly across 16 partner products, and a Marketplace plus "Sign in with ChatGPT" are launching. In OpenAI's words, ChatGPT is becoming "a shared surface where humans and agents collaborate," and developers can ship native experiences directly to 1.2 billion weekly users.
Plugin Extensions: Sidebars and Interactive Panels Grow Inside ChatGPT
Plugin extensions give plugins their own home in the ChatGPT sidebar, let them build interactive panels, and create viewers for the file types their products support. Launch examples include a meetings app, Figma designs that can be revised mid-conversation, and Photoshop features from Adobe. The keynote had a refreshingly candid line: "We have tried versions of this before, admittedly with some mixed results; but this time is different, because we are giving developers the same tools we use to build ChatGPT ourselves." Plugin extensions are available on all plans. The always-on agent dots relies on the same plugin ecosystem to reach more than 4,000 apps.
Allowance Sharing: Plus and Pro Quotas Work Across 16 Products
ChatGPT subscribers can now spend their subscription allowance directly inside 16 partner products — including Cognition's Devin, Notion, Vercel, T3, OpenClaw, and Dactyl — with controls on how much each product may use; eligible OpenAI usage counts toward plan limits. On the identity side, "Sign in with ChatGPT" is going live globally: users sign in to third-party apps with their ChatGPT account, plugins connect faster, and there are fewer passwords to manage.
A Head-On Challenge to the App Store
Put the three pieces together and OpenAI's intent is clear: plugin extensions answer "what do apps look like," the Marketplace answers "where are apps discovered," and allowance sharing plus unified sign-in answer "how do money and identity flow." Launch partners for the Marketplace reportedly include Adobe, Canva, Figma, Notion, Salesforce, Vercel, and Zendesk. 1.2 billion weekly users are the foundation of this platform logic — once the distribution surface is big enough, developers will build native experiences for ChatGPT specifically. The real test comes later: app discovery and ranking, quality review, and permission management are all potholes the mobile app stores hit years ago. Whether OpenAI avoids them will decide if this is a "new platform" or "another plugin store."
