Blockchain-based fan tokens provide token holders with certain rights, incentivizing fan engagement and decision-making within sports organizations. Despite the recent surge in interest, acceptance and technical advancement, a profound understanding of the technical, functional, and conceptual foundations of fan tokens is still lacking, necessitating further research and practical insights. Drawing on customer and fan engagement theory and utilizing a single case study approach, we analyzed the market-leading platform Socios for the issuance and operation of fan tokens. Our analysis yields a generic blockchain-based fan token framework that includes the constructs: 1) Trust and efficiency layer, 2) utility and 3) financialization features. The latter two constructs promote fan token holder empowerment. In addition, we extend the current definition of fan tokens to the context of blockchain. Our findings indicate that fan tokens are still in a nascent stage, requiring continued research and development.