"native" swap contracts

[ca333]

For swaps between assets from the same protocol (eth, bsc, cosmos, etc.) we can leverage/utilize protocol-specific atomic swap contracts/modules/libs for efficiency increase (tx fees, speed, etc.). e.g. if alice swaps an erc20 asset for an erc20 asset it would make sense to utilize a native erc20toerc20 atomic swap contract instead of the atomicDEX specific swap protocol as it saves money/time.

For certain protocols we should additionally explore potential (non ponzi-based) "AMM" tech adoption and possible evolution into hybrid arch with a combination/fusion of both order book and liquidity pool model. This specific topic likely requires separate issue ticket, however I brought it up here since it seems relevant.

inspiration:
https://github.com/tendermint/liquidity (interesting/envisions such a hybrid model)
uniswap, pancake swap, osmosis, etc.
https://betterprogramming.pub/uniswap-smart-contract-breakdown-ea20edf1a0ff
https://cryptomarketpool.com/trustless-token-swap-in-a-solidity-smart-contract/

[artemii235]

Thanks for creating the issue!
I propose to start with UI/UX concepts to understand how it should work/look in general in our GUIs. API implementation will also depend on this. cc @tonymorony

Additional idea on this topic: in case users want to e.g. buy BTC-BEP20 for USDT-BEP20, we can show them an offer to buy native BTC directly using atomic swaps. It might be a good option for some of them if their final goal is to receive actual BTC. This way, they can avoid using a separate BTC-BEP20/BTC bridge, which can also save some funds on transaction fees.