TetherBack is a relatively new player in the crypto cashback space. To determine whether it's safe, we need to examine its security model.
Any third-party service that connects to an exchange account requires some level of access. This can range from requiring API keys with trading or withdrawal permissions, which grant real control over an account, to needing only a public identifier. The former is riskier and should be avoided, while the latter is safer.
TetherBack sits at the safer end of this spectrum. It doesn't execute trades, hold user funds, or request API keys or login credentials. Instead, it links accounts using the UID (unique identifier) assigned by the exchange. This means that even if TetherBack were compromised, it wouldn't have access to user assets.
The non-custodial model used by TetherBack is a key aspect of its security design. Funds remain on the exchange throughout, and trades are placed and settled there. Margin is also held on the exchange, and withdrawals are controlled by the user through the exchange itself. This separation limits the platform's reach and confines its potential impact in an adverse scenario.