OpenAI gave developers a way to live permanently inside ChatGPT at DevDay on September 29: plugin extensions give a plugin a dedicated home in ChatGPT's sidebar rather than a one-off tool call. Developers can also build interactive panels users work in alongside the conversation, plus viewers for whatever file types their product uses — available on every ChatGPT plan.

A new Plugin Creator tool handles the build side, submission now runs through a redesigned flow with clearer feedback, and improved ranking surfaces plugins in the directory and live conversations. Plugins can trigger automations off events in a connected app — for example, watching a project board and drafting a plan while the user is away — via OpenAI's new support for the proposed MCP Events specification.

Business, Enterprise, Healthcare and Edu customers can host supported plugins inside the ChatGPT Sites they build, sharing one connected app across a workspace with per-member permissions. TechCrunch read the move as a direct challenge to app-store distribution, now that ChatGPT counts 1.2 billion weekly users.