Their reasoning is called "extending thinking". It was released alongside Claude Sonnet 3.7. They have web search, but it's true, no "deep research". It honest

Their reasoning is called "extending thinking". It was released alongside Claude Sonnet 3.7. They have web search, but it's true, no "deep research". It honestly is not very good and it's WAY too trigger-happy with it. As a result, if you accidentally leave it on, you get terrible answers to simple questions that non-search mode would have answered well. (And for context Claude Sonnet 3.7 is my model of choice)