savings-dai

Proof Of Concept for how a Savings DAI token could be implemented to work with the Multicollateral DAI's DAI Savings Rate.

Note: the code in this repo has not been audited or formally verified. It should not be considered production-ready! Use at your own risk!

How to Use

A user with a balance of dai in the Vat can exit into Savings Dai token. This will move their Vat.dai balance to the adapter's pot.pie balance and mint them sDai.

Savings Dai is an ERC-20 token. It can be transfered, approved, etc. The Join Adapter is an authorized contract for the Savings Dai contract so that it has authority to mint new tokens.

No other special permissions are required. Users much approve and hope on the adapter to allow it to move their tokens/balances in and out.

How to get Savings Dai:

(As a user with dai in the vat)

1. call Vat.hope on the join contract
2. call join on the join contract with the address (usr) you wish to receive the sDai and the amount (wad) you wish to receive (not to exceed your dai balance).

Note: for calculating wad this should be the amount of dai you wish to move from your vat account. For instance, if you have 100 Dai in the vat (denominated in the vat as 100 ether * 10 ** 27 = rad(100)), you should use 100 ether as your wad value. The adapter will convert it to rad and move the appropriate amount of dai in the vat and then will calculate the appropriate amount to be joined into the pot (i.e. rad / pot.chi()) and mint that amount of pie as Savings Dai. This means that you will receive fewer sDai than vat.dai but when you later redeem them (join back into the vat), you will receive the original amount of dai + the interest earned through the DSR.

How to redeem Savings Dai:

(As a user with sDai in your wallet)

1. call approve on the Savings Dai contract with the join address and the amount you wish to redeem
2. call exit on the join contract with the address (usr) you wish to receive the dai and the amount (wad) you wish to redeem (not to exceed your sDai balance).

How to setup:

(Assuming the DSS system is launched)

1. Deploy the SavingsDai token with the network id as the only parameter.
2. Deploy the SavingsDai Join adapter contract with the vat address, the pot address and the Savings Dai token address as the three parameters.
3. From the address with which you created the SavingsDai contract, call SavingsDai.rely(address(joinAdapter)) to authorize the Adapter to mint tokens.
4. From the address with which you created SavingsDai contract, call SavingsDai.deny(address(<your-address>)) to deauthorize your deploying address from the token contract.

Note: Users should ensure that only the adapter is relyed upon by the SavingsDai Token before interacting with it as any address that is authed in that manner will be able to mint new SavingsDai. Interacting with a token contract that has not been secured could lead to a loss of funds.