Summary:

Gasless feature enables users to use Kromatika swap feature, without paying any gas fees in the native chain token. No ETH or MATIC is needed to execute a swap transaction. Instead one can pay gas fees in the token you swapping are for.

Abstract (WHAT)

We propose deploying a series of contract which will adopt the adapter design pattern, which ultimately makes the dapp more scalable, secure and efficient, while achieving flexibility for easier integrations towards other features. It means if the users is making gasless swap, the gasless adapter contract will be called from the router contract or if the user uses limit orders, the limit order adapter contract will be called. There is stateless flashwallet contract which is intermediary between the adapters and the router contract. Its goal is to achieve safe transfer of funds, while not keeping any funds into its custody.

Motivation (WHY)

Very often user needs to have ETH native token in order to make swaps on a DEX. In many cases especially when new wallets are created or ERC20 tokens bridged, users are finding themselves short of ETH to pay gas for swap. How can we bridge the gap between CEX and DEX & offer the users the same user experience that they can find on CEX. On CEX, the users don't need to hold ETH in order to trade/swap any trading pairs. Can we do the same on a DEX ?

Specification (HOW)

This issues will be solved by Kromatika's gasless feature by utilizing relayer provided by Biconomy. The relayer pays for the transaction fee on behalf of the user, but it also charges the txn fee amount from the token the user would receive. Any (transferrable - no honeypot tokens) ERC20 token could be used as a payment token.

Example:

Imagine that you need to swap USDC to LINK, but you do not have any ETH or MATIC to pay for it; Using gasless mode, all you need to do is:

1. Sign an approval to Kromatika to use your USDC (free for tokens that use the Permit-712 standard)
2. Sign the execution of the swap transaction (no fees paid)

Example:

1. Choose input token -> USDC
2. Choose output token -> LINK
3. Choose amount of USDC that you want to spend
4. Sign USDC approval transaction
5. Make swap transaction (which is sign transaction, so the relayer could execute the transaction on your behalf) Background:
6. Relayer publishes the txn => pays for the txn on user behalf from relayer gas tank (personal wallet). Ex: fee is 0.02$ on Polygon
7. Relayer deducts 0.02$ worth of $LINK (any transferrable ERC20 token) from the output user would receive.
8. User receives $LINK token

Benefits:

Gasless swap is feature that is regarded as Kromatika protocol upgrade and the goal is to offer a feature that will greatly expand the horizon of possibilites while maintaining the idea of Kromatika as one stop shop service for DEX users. It is not designed to have direct benefit or relation to any token as the team is only focused on improving the protocol and the protocol usage experience.

Gasless swaps benefits include:

• CEX experience, while using the benefits of a decentralization and DEX
• Best quotes: it utilizes Kromatikas advanced aggregation which offers best quotes
• Better investment opportunities: since you do not need funds gas fees, you could put your gas funds to use, instead of sitting around passively and pay with potential profits from a successful trade.
• Any transferrable ERC20 token could be payment token
• Greater partnership potential and discounts promotion potential for users : Partners/whitelisted parties can run a relayer and offer a discount on txn fees, discounts involving advertised token or even airdrop campaign.
• Great potential of gasless concept: the gasless concept could be extended to limit orders or other blockchain operation.

Associated costs:

In order to fully develop, implement and offer stable and secure gasless feature, there are associated costs which will be used for:

• security audit of involved smart contracts
• server infrastructure costs
• deployment costs
• relayer gas tank load
• promotional costs