The User is able to verify contract authenticity with or without an API. The storage and full access is available only through an API. This is because we store records publicly and only the fingerprints of particular form fields (a cryptographic hash function). It means one can, without the API, verify IF someone owns a property, but not WHO owns it.
The UBITQUITY API was developed in Python programming language, utilizing Django REST framework, and web3.py interface for interacting with the Ethereum blockchain & ecosystem, although our API supports multiple blockchains in our mission to be ledger agnostic. We support permissioned and permissionless chains.
A smart contract prepared from Ubitquity is designed to make contract elastic, and in essence no interference in it is required to store additional data.
All the necessary changes can be done by performing standard changes in API, requiring no specialized blockchain-related knowledge. See: SmartEscrow™