Your tarn
Deposit USDG, let it earn, and spend only the interest. Everything here is read from Robinhood Chain and every action is a transaction you sign.
You're early: Tarn's two contracts go on chain with the first deposit or trade anyone makes. If that's you, your wallet asks for one extra transaction first (about 0.0001 ETH of gas, once for everyone). The addresses are fixed by the code, and nobody owns the contracts afterwards.
Actions
Deposit puts your USDG into Steakhouse USDG on Morpho through TarnVault and gives you tUSDG. Its value rises with the interest, and what you put in is recorded as your principal.
Withdraw takes USDG out, principal and interest together, in proportion. Withdraw everything and you get all of it.
Harvest pays out the part of your tUSDG that's worth more than you put in. Take it as USDG, or have it buy a stock in the same transaction. Your principal stays in the vault, still earning.