Using COINS to pay for fees

About “Using COINS to pay for fees”

CoinSwap.com is the first DEX in the world which uses the platform token COINS to pay for transaction fees and the discount rate will be up to 50%. The COINS used to pay for fees will be burned as deflation.

Assuming that in a transaction you have to pay 100 USDC for fees and the discount rate is 50%, then you only need to pay 50 USDC worth of COINS for fees.

Conditions for “Using COINS to pay for fees”

1. Trading areas in the whitelisted areas, such as USDT, USDC, BTC, ETH, BNB, COINS and others.

2. Users enable the "using COINS to pay for fees" function.

3. Users have enough COINS in the wallet.

Whitelisted trading areas

Binance Smart Chain(BSC)

Trading Area	Contract Address
USDT	0x55d398326f99059ff775485246999027b3197955
BUSD	0xe9e7cea3dedca5984780bafc599bd69add087d56
BNB&WBNB	0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c
COINS	0xC53C40FB8Ed1522fB9B5a500ae89Bc6b1BbC9302

*The specific parameters are subject to the actual situation.

Coins used to pay for fees will not participate in rebates but be directly burned.

Discount Rate

Time	Discount Rate
The 1st year	50%
The 2nd year	60%
The 3rd year	75%
The 4th year and beyond	75%

Calculation rules of “COINS pay for fees”

Coinswap.com uses the classic formula X * Y = K. In Uniswap V2, the default is to charge a 0.3% trading fee, which is calculated based on the ΔX deposited in the resource pool. That is, 0.3%*ΔX Tokens X will be first deducted. Coinswap.com quoted a virtual transaction volume ΔV.

(X+ΔX)*(Y-ΔY)=K         (1)
ρ=0.3%                  (2）
ΔV-ΔV*ρ=ΔX              (3）

From (3), the trading fee of this transaction can be calculated. Fee 1 is the transaction fee of the payment token.

fee1=ΔX/（1-ρ）-ΔX        （4）

According to formula (1), fee 2 can be calculated and fee 2 is the dollar value of fee 1.

(X+fee1)*(Y-fee2)=K     （5）
θ=0.5                   （6）  
Θ is the discount rate of the platform token

In the same way, the fee 3 can be calculated, which is the platform token value of the corresponding fee after the discount.

(X+fee2)*(Y-fee3)=K      （7）
fee4=θ*fee3              （8）

Fee 4 is the number of COINS that needs to be burned.

Note: Fee 2 and fee 3 are pre-calculated and will not affect the liquidity pool.

This function adopts the token whitelist system. All the transaction fees incurred in transactions with the currencies in the whitelist can be paid by the COINS, which is controlled by the super authority. The super authority will be handed over to the community in the future.