DevDay 2026 remakes ChatGPT into a platform with open plugins, workspaces and an enterprise marketplace

OpenAI used DevDay to reposition ChatGPT as a platform. The new open plugin system lets third parties ship app-like interfaces inside ChatGPT. Shared workspaces and automations let teams run recurring workflows. Native Slack and Teams integrations plus an enterprise marketplace target the corporate buyer directly. The Decoder summarized it as a ChatGPT that 'looks less like a chatbot and more like an operating system.'

The mechanics matter for developers. Plugins now carry UI rather than just API calls, automations can run without a user prompting them, and the marketplace gives OpenAI a distribution and revenue-share layer similar to an app store. New pricing tiers accompany the launch. The ChatGPT Pro 500 tier drew a heavily critical HN thread (190 points, 219 comments) over what users describe as a downgrade of the existing $200 plan.

The skepticism is historical. Ethan Mollick noted that OpenAI seems to release 'a variation on the same third-party ecosystem only to semi-abandon it: Plugins in 2023, GPTs and the GPT Store in 2023-2024, Apps in 2025, and now Plugins (same name, different thing than before) in 2026.' Developers also worry about platform lock-in if ChatGPT becomes the OS that mediates their customers.

Competitively, this puts OpenAI directly against Microsoft's new Copilot Autopilot and Meta's Enterprise Platform. All three are fighting for the enterprise work layer. Watch whether major SaaS vendors commit to the marketplace, and whether OpenAI keeps this ecosystem alive longer than the last three.