LLM Token Price Index The Token Price Index (TPI), a free public index tracking the cost of AI inference over time, has been launched to provide a transparent benchmark for frontier AI pricing. Updated weekly, the TPI offers analysts, engineers, and finance teams a shared reference point for state-of-the-art AI costs. AI Token Price Index Token Price Index TPI is a free, public index tracking the cost of AI inference over time. Updated weekly, the TPI publishes a single, methodologically transparent number for frontier AI pricing — giving analysts, engineers, and finance teams a shared reference point for what state-of-the-art AI actually costs.