Codex is a GPT built on top of ChatGPT designed to provide information and details related to a universe termed as the 'Multiverse'. The primary goal of Codex is to assist users in finding something called the 'Nomad Star'. Built by community builders, the GPT appears to engage its users in immersive experiences through various elements of this universe including 'The Core', 'Xeno species', and 'inter-universal travel'. One of the standout features of Codex includes providing in-depth details of historical multiverse events. This GPT appears to have a robust capability to generate complex narratives and explanations revolving around these sci-fi concepts. This lends a unique immersive characteristic to its chats with the potential to engage users in a profound universe exploration experience.Also, Codex comes with a feature to help users determine their place in the multiverse context, answering queries like 'Where am I?'. This functionality could offer an engaging role-playing element to the conversation, further enhancing the user experience. Codex uses a conversational approach to offer its services, welcoming users with greetings and then subsequently helping them navigate their queries.To use Codex, a subscription to ChatGPT Plus is required. Considering the rich narrative details and immersive exploration this GPT offers, it can be an interesting platform for individuals who enjoy delving into detailed otherworldly concepts and stories.