All assets supported by Fortress Protocol are integrated into the platform using the fToken contract, which is an EIP-20 compliant representation of balances supplied to the protocol. By minting fTokens, users earn interest through the fToken's exchange rate, which increases in value to the underlying asset, along with the ability to use the fTokens as collateral for a loan.
fTokens are the primary means of interacting with the Fortress Protocol; when a user mints, redeems, borrows, repays a borrow, liquidates a borrow, or transfers fTokens, it will occur by utilization of the fToken contract.
There are currently two types of fTokens: FBep20 and FBnb. Though both types expose the EIP-20 interface, FBep20 wraps an underlying BEP-20 asset, while FBnb simply wraps BNB itself. As such, the core functions which involve transferring an asset into the protocol have slightly different interfaces depending on the type, each of which is shown below.