OpenAI has temporarily stopped taking new subscribers for its $200-a-month Pro plan, saying demand for its newest model, Astra, is putting unprecedented strain on its infrastructure.

The change was announced on X by Thibault Sottiaux, the product leader who oversees ChatGPT and Codex. He said the Pro tier draws most heavily on the company's systems, which is why sign-ups for that tier were switched off. "We wanted to take the smallest step that allows us to continue giving the broadest access possible," he wrote, adding that the API and the cheaper Go and Plus plans remain available.

OpenAI signalled the move a day earlier. "Demand for Astra is really unprecedented," Sottiaux wrote on Wednesday. "We're pulling all the levers possible to sustain the demand, but I've not seen anything like it until now, and we went through very steep growth before. Priority will always be to keep excellent service for existing users, but we might have to pause new Pro subscriptions for a bit if this continues."

The company has not said how long the pause will last or how many people are signing up each day, so the scale of the demand remains opaque. It raised usage limits for Codex users as recently as last month, suggesting the pressure is recent.

Astra launched on 3 September and has been rolling out across Pro, Plus, Enterprise and Business accounts. OpenAI has pitched it as a generational leap in reasoning, coding and computer use, and framed it as the start of the "AGI era" — marketing that appears to have fed the surge it is now struggling to serve.

The pause is an unusual admission for a company that sells subscriptions: instead of an outage, OpenAI has capped its own sales at the top end of the market while it adds capacity.