Tortuga Finance ($TAPT) is the platform where users can stake APT and get tAPT (Tortuga Staked APT), which allows users to stay staked while participating in the Aptos DeFi ecosystem.
The Tortuga protocol accepts APT and returns tAPT tokens. tAPT may be exchanged with the protocol for APT with a delay of up to one unlock period, which is set by the Aptos chain. This is described in §4.4. The Tortuga protocol puts the APT in reserve. The protocol may stake or unstake the reserve with its associated validators, that is, the validators interfacing with the Tortuga open-source code. The protocol is in deficit if the APT in the reserve is less than the APT required to service tAPT swaps. This can happen because APT is temporarily locked by Aptos when it is staked. In this case, the contract can be called permissionlessly to unstake APT from associated validators. If the protocol is not in deficit, then total stakable amount that can be staked with associated validators is nonzero and anyone can increase stake in associated validators.