DApp360 DCA Plutus contract

This repo is forked from ADAPhilippines/plutus-v2-starter-kit Only Contract.hs is being worked on now. The project structure will be considered later.

Minimum Viable Product

The current MVP implementation is described here. The full implementation is here

General Idea

A user locks some ammount of ADA in the PlutusV2 validator script (dcaScript) UTxO and specifies how much of ADA should be swapped to TokenB with specified periodicity. Swapped asset TokenB goes directly to the user's wallet. Any time a user can close his posiotion, i.e. withdraw all funds from the dcaScript.

Anyone can perform swaps on a dedicated page. A user performing swap will be rewarded with a small botFee

Validator Script Logic

The dcaScript validator has 2 endpoints (actions) defined by Redeemer:

• swapDCA to perform swap from ADA (locked in dcaScript UTxO) to TokenB. Can be done by anyone.
• closeDCA to withdraw all funds from the dcaScript UTxO.

Regardless of the endpoint the validator must not allow malicious withdrawal of funds

Opening DCA Position does not consume any UTxO from the dcaScript, hence it doen't trigger the validator. However the offchain code must ensure that only 1 DCA Position is open for the same owner (or validator should be updated to protect from doublespending)

CloseDCA

The redeemer is parametrized by TxOutRef of the UTxO to be closed. So only 1 UTxO can be closed at a time (1 should exist) The validator must ensure that:

• The UTxO being consumed is TxOutRef
• All tx outputs go to the owner. As a consequence, only owner can build this tx (not 100% sure about this)
• Tx is signed by owner

SwapDCA

This Tx can be submitted by anyone. This Tx can consume several UTxOs (for several owners) in the same Tx. The validator is run separately for every UTxO consumed. So validator logic is per 1 UTxO currently being validated. The validator must ensure that:

• The correct amount is sent to DEX and the change - fees goes back to the dcaScript.
• Output to DEX = swapAmmount + 2 Ada Batcher fee + 2 Ada collateral
• Change back to dcaScript = ammountLockedAtUTxO - outputToDEX - botFee - txNetworkFee
• The DEX Datum is constructed correctly and the swap result will go to the owner.
• The Change Datum back to dcaScript is constructed correctly.
• The now() is greater then nextSwap. So the swap is allowed.

Possible vulnarabilities

If there are 2 UTxOs in dcaScript for the sawe owner with the same swapAmmount, an attacher can consume both, but send only 1 to DEX. Solution: check ScriptContext for all consumed UTxOs and for N inputs ensure N correct DEX outputs.