From Open AI: ChatGPT Plus and Team users will be able to access o1 models in ChatGPT starting today. Both o1-preview and o1-mini can be selected manually in the model picker, *and at launch, weekly rate limits will be 30 messages for o1-preview and 50 for o1-mini*.
This model is scary smart, but please keep in mind that there are message limits to using it that will reset WEEKLY, not every 3 hours like the other models.