Google says the three models are rolling out now in private preview, and OpenAI says general availability is planned in the coming weeks. You buy them through Google Cloud Marketplace, so usage lands on your Google Cloud invoice and draws down existing Google Cloud spend commitments.
OpenAI says Codex workflows are part of the deal, and that its models will also come to Google Antigravity and the Gemini Agent soon. Google says prompts and outputs stay inside your data perimeter and aren't used for training, with zero data retention options and Confidential Compute marked as coming soon.
Google now says it's the only big cloud with all three leading closed model families. OpenAI's post ends by noting that Microsoft remains its primary cloud partner.