A typical smart contract design pattern is to store the unique hash returned by Sia for any uploaded data files (JSON, PDF, media, text). The files are immutable and remain available as long as at least a single Sia node has them hosted. Files stored on Sia are “content addressable” which means that once the hash for a file is known, it can be retrieved from any Sia “gateway” (the portion of the Sia node that enables web access to files). The front-end UI for the smart contract (if any) can fetch and display the file content for users from any Sia gateway with just the hash stored in the smart contract.