OpenAI is turning ChatGPT into a platform where plugins run
In its DevDay 2026 recap, published on September 29, 2026, OpenAI announced plugin extensions that let developers build custom experiences inside ChatGPT, Sites that can host plugins, event-triggered automations through MCP Events, Sign in with ChatGPT and an enterprise OpenAI Marketplace. The company says ChatGPT has 1.2 billion weekly users.
The platform side of more than 20 announcements
OpenAI's DevDay 2026 recap, dated September 29, 2026, lists more than 20 major announcements spanning ChatGPT, Codex, its models and new ways of working with AI. This article covers only the plugin, distribution and identity pieces of that list. The company's framing is direct: it is opening ChatGPT as a shared surface where developers can launch new native experiences straight to a collective 1.2 billion weekly users.
Plugin extensions sit at the centre of the package. OpenAI says it is opening up the platform it uses to build ChatGPT's own features. Developers can give a plugin its own spot in the sidebar, build interactive panels that people use next to the conversation, and add viewers that open the file formats their own product handles. The feature is available on all plans. TechCrunch points out that plugins already connect ChatGPT to tools such as Slack, SharePoint, Airtable and Google Drive; what is new is an app-like interface around them.
Building, discovery, sharing and automation in one package
A new Plugin Creator tool helps developers build plugins, and a redesigned submission flow gives clearer feedback. TechCrunch reports that the new flow shows developers where their review stands and what has to change. It also lets them ask for a person to look at the plugin and change its tools without resubmitting from scratch. Ranking and recommendations are also being improved, both in the plugin directory and inside conversations. Control stays with the user. In OpenAI's words, "Users choose which plugins to use and approve the access each one receives."
The second piece is Sites, the lightweight websites people build with ChatGPT, which can now host supported plugins. Colleagues in the same workspace can open that app as well, each working from the data and permissions they have connected. This is available on Business, Enterprise, Healthcare and Edu plans. The third piece is MCP Events. OpenAI is building in support for this specification, which is still only a proposal. With it, a plugin can kick off an automation when an event occurs in an app it is connected to. In the company's example, ChatGPT watches a project board for new tasks and, when one arrives, reads the linked documents and drafts a plan, even while the user is away. MCP Events support is available on all plans.
Identity, enterprise purchasing and the app store debate
Sign in with ChatGPT lets people draw on their ChatGPT plan inside 16 partner tools and cap how much each one may use. OpenAI names six of them: Notion, Vercel, T3, OpenClaw, Dactyl and Cognition's Devin. Signing in to tools with a ChatGPT account also makes it faster to connect plugins. The identity layer is available globally, while OpenAI notes that "Plan usage is available to Plus and Pro users in participating tools." Through OpenAI Marketplace, qualifying enterprise customers can put a portion of the spend they have already committed to OpenAI toward software from approved partners. Among the first 32 partners, OpenAI groups Adobe, Salesforce, HubSpot, ServiceNow, Sierra and Decagon under customer experience. It places Harvey and Legora in legal, and CrowdStrike and Palo Alto Networks in cybersecurity. Figma covers creative work and Baseten open-source models. Enterprise customers can register their interest. TechCrunch puts the launch roster at 30-plus partners, while OpenAI and Decrypt give 32.
TechCrunch presented the package as a direct challenge to the app store model; that framing is the outlet's reading, not OpenAI's wording. The same report adds that OpenAI announced no billing or revenue-sharing plan at the event, nothing that would mirror the economic layer of a traditional app store. For a business, the implication is that as ChatGPT opens a sidebar, panels and event-triggered automations to plugins, how a service looks inside ChatGPT may come to matter as much as its website. MCP Events is still only a proposed specification. Our own reading is that basing automations on a common specification, rather than on one product's closed interface, could make them less dependent on a single vendor. And because users approve each plugin's access one by one, data and permission design moves to the centre of plugin development. We covered the paid visibility side of ChatGPT, Sponsored Agents opened from ads, on September 17; these announcements widen the developer side of the same channel.
The sources say nothing about Türkiye, so this section is commentary
None of the four sources contains any information about Türkiye. OpenAI's recap describes availability for plugin extensions, plugin hosting in Sites and MCP Events by plan rather than by country; the only piece it explicitly calls global is the identity side of Sign in with ChatGPT. What follows is therefore not a fact drawn from the sources but explicitly UNALSOFT commentary.
The unknowns, one by one: whether these features will reach Türkiye with any regional restriction; who the 10 unnamed partners among the 16 for Sign in with ChatGPT are; any revenue share or commission terms for plugin developers and Marketplace partners; which enterprise customers count as eligible for the Marketplace and how much of a commitment can be applied to partner software; and when the MCP Events specification will move beyond the proposal stage. Our reading: for a business whose customers use ChatGPT, the real question is not whether to build a plugin but what a customer sees when they find the service inside the conversation. Because plugin extensions are available on all plans, that question is not reserved for large companies.
UNALSOFT's take
We read these announcements less as a single product launch and more as a distribution channel taking shape. Plugin extensions and MCP Events open a technical path for turning a service into a tool that works inside the conversation, and into an automation that reacts to an event in a connected app. In practice that means two steps: first pick the workflow that genuinely creates value inside a chat, then design up front which data each plugin reaches and with which permission, because users approve every access separately. In our agentic AI work, agent and automation design starts from exactly that permission map.
What will your service look like inside ChatGPT?
A short conversation is enough to map which of your workflows could become a plugin or an event-triggered automation.