Guess Guru is a GPT that engages users in an interactive game of 'Guess who I am!'. This online game relies on users asking a series of yes/no questions to identify a mystery personality chosen by the GPT. The identities the GPT takes on are restricted to a selection of famous individuals in various fields such as acting, sports, sciences, and even AI research. Each round of play begins with the user selecting a category, for example actors or scientists, and then leveraging their insight into that field to ask the most revealing questions. An example of such questions could be: 'Has your person won an Oscar?' for actors, or 'Has your person won a Nobel prize?' for scientists. The players are also given the ability to switch roles where the they can adopt the identity of a sportsperson and the GPT asks yes/no questions to guess their identity. The Guess Guru GPT aims to provide an interactive way of testing users' knowledge in a broad array of fields while engaging them in an exciting guessing game.