Mint with ETH

[superduck35]

NOTE - this is particularly challenging because of how hard it is to test and develop in a test environment. If using Ropsten, beware of the mix-match between the different versions of the ERC20 tokens used by the different protocols

Is your feature request related to a problem? Please describe.

Users might want mUSD but not have any bAsset available to mint with. If the user just has ETH, then we should support this on the MINT page by first buying the required bAsset and then minting with it.

Describe the solution you'd like

A new function on the MINT page to support minting with ETH. This would be seperate from the current 'advanced' implementation and help us start to support a 'lite' and easy method of allowing users to MINT. Make this easy for the user while retaining existing functionality.

The functionality at a high level is:
Step 1: User chooses that they want to mint with ETH
Step 2: Purchase required bAsset with ETH
Step 3: Mint with the bAsset

There are many ways this could be implemented.. here are two:

• Using 1inch integration provided by mStable to buy bAsset and then MINT in 1 transaction (1inch is only on mainnet)
• Sending 2 transactions back to back, by first linking in to Balancer, Uniswap, 1inch or Kyber to buy the bAsset, and then sending a second transaction to do the MINT
  • Or create your own implementation and submit it to the mStable-contracts repo

Bonus points
Optimise the overall cost to the user to provide them with the cheapest mint

Additional context

It might and probably would be cheaper just to purchase mUSD on the third party exchange instead of buying ETH. This is not always guaranteed to be cheaper though. The benefit to minting is that it helps grow the mUSD token. If you choose to go down the path of just purchasing mUSD on a third party exchange, justify it here.

Feel free to reach out to the team for any further information.