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Outlined below are three methods to remove liquidity from an existing pool:
Contract ID: SaucerSwapV1RouterV3
A spender allowance for the router is required for the LP token.
removeLiquidity supports HTS tokens with custom fees.

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Removing HBAR/Token Liquidity

Remove liquidity from an existing HBAR/token liquidity pool. Function name: removeLiquidityETH ⛽ Recommended gas: 2,800,000 gwei (~ $0.24 USD)
Parameter NameDescription
address tokenEVM address of the token paired with HBAR
uint liquidityLP liquidity amount to remove
uint amountTokenMinThe minimum token amount to receive in its smallest unit
uint amountETHMinThe minimum HBAR amount to receive in its smallest unit
address toEVM address to receive the tokens
uint deadlineDeadline in Unix seconds
function removeLiquidityETH(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external returns (uint amountToken, uint amountETH);

function removeLiquidityETH(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
  safeAssociateToken(address(this), token);
  (amountToken, amountETH) = removeLiquidity( 
    token,
    whbar, 
    liquidity,
    amountTokenMin,
    amountETHMin,
    address(this), // used to be msg.sender
    deadline
  );
  safeTransferToken(token, address(this), to, amountToken);
  safeApproveToken(whbar, WHBAR, amountETH);
  IWHBAR(WHBAR).withdraw(address(this), to, amountETH);
  safeDissociateToken(address(this), token);
}
The removeLiquidityETH function operates in HBAR but derives its name from Uniswap on Ethereum. This name was kept to simplify integration for developers versed in Uniswap tools.

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Code Overview

Resources:
Typescript
import { 
  ContractFunctionParameters, 
  ContractExecuteTransaction, 
  AccountAllowanceApproveTransaction,
  .. 
} from '@hashgraph/sdk';

//Client pre-checks:
// - Router contract has spender allowance the LP token

const params = new ContractFunctionParameters();
params.addAddress(tokenAddress); //address token  
params.addUint256(lpTokenAmountToRemove); //uint liquidity
params.addUint256(amountTokenMin); //uint amountTokenMin
params.addUint256(amountETHMin); //uint amountETHMin
params.addAddress(toSoli); //address to
params.addUint256(deadline); //uint deadline
    
const response = await new ContractExecuteTransaction()
 .setContractId(routerContractId)
 .setGas(gasLim)
 .setFunction('removeLiquidityETH', params)
 .execute(client);
 
const record = await response.getRecord(client);
const result = record.contractFunctionResult!;
const values = result.getResult(['uint','uint']);
const amountToken = values[0]; //uint amountToken
const amountHBAR = values[1]; //uint amountETH

​
Removing Token/Token Liquidity

Remove liquidity from an existing token/token liquidity pool. Function name: removeLiquidity ⛽ Recommended gas: 1,600,000 gwei (~ $0.14 USD)
Parameter NameDescription
address tokenAEVM address of the first HTS token
address tokenBEVM address of the second HTS token
uint liquidityLP liquidity amount to remove in its smallest unit
uint amountAMinThe minimum amount for the first token in its smallest unit
uint amountBMinThe minimum amount for the second token in its smallest unit
address toEVM address to receive the tokens
uint deadlineDeadline in Unix seconds
function addLiquidity(
  address tokenA,
  address tokenB,
  uint amountADesired,
  uint amountBDesired,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);

function addLiquidityNewPool(
  address tokenA,
  address tokenB,
  uint amountADesired,
  uint amountBDesired,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external virtual payable override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
  
  require (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0), "UniswapV2Router: POOL ALREADY EXISTS");
  address pair = IUniswapV2Factory(factory).createPair{value: msg.value}(tokenA, tokenB);
  
  (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);

  safeTransferToken(
    tokenA, msg.sender, pair, amountA
  );
  safeTransferToken(
    tokenB, msg.sender, pair, amountB
  );
  liquidity = IUniswapV2Pair(pair).mint(to);
}

​
Code Overview

Resources:
Typescript
import { 
  ContractFunctionParameters, 
  ContractExecuteTransaction,
  AccountAllowanceApproveTransaction,
  .. 
} from '@hashgraph/sdk';

//Client pre-checks:
// - Router contract has spender allowance for the LP token

const params = new ContractFunctionParameters();
params.addAddress(tokenAAddress); //address tokenA
params.addAddress(tokenBAddress); //address tokenB
params.addUint256(amountADesired); //uint amountADesired
params.addUint256(amountBDesired); //uint amountBDesired
params.addUint256(amountAMin); //uint amountAMin
params.addUint256(amountBMin); //uint amountBMin
params.addAddress(toAddress); //address to
params.addUint256(deadline); //uint deadline
    
const response = await new ContractExecuteTransaction()
 .setContractId(routerContractId)
 .setGas(gasLim)
 .setFunction('addLiquidityNewPool', params)
 .execute(client);
 
const record = await response.getRecord(client);
const result = record.contractFunctionResult!;
const values = result.getResult(['uint','uint']);
const amountA = values[0]; //uint amountA
const amountB = values[1]; //uint amountB

​
Removing HBAR/Token Liquidity Supporting Tokens with Custom Fees

Remove liquidity from an existing HBAR/token liquidity pool supporting HTS tokens with custom fees on transfer. Function name: removeLiquidityETHSupportingFeeOnTransferTokens ⛽ Recommended gas: 3,000,000 gwei (~ $0.26 USD)
Parameter NameDescription
address tokenEVM address of the token paired with HBAR
uint liquidityLP liquidity amount to remove in its smallest unit
uint amountTokenMinThe minimum token amount to receive in its smallest unit
uint amountETHMinThe minimum HBAR amount to receive in its smallest unit
address toEVM address to receive the tokens
uint deadlineDeadline in Unix seconds
function removeLiquidityETHSupportingFeeOnTransferTokens(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external returns (uint amountETH);

function removeLiquidityETHSupportingFeeOnTransferTokens(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) public virtual override ensure(deadline) returns (uint amountETH) {
    safeAssociateToken(address(this), token);
    (, amountETH) = removeLiquidity(
      token,
      whbar, 
      liquidity,
      amountTokenMin,
      amountETHMin,
      address(this),
      deadline
    );
    uint256 amountToSend = IERC20(token).balanceOf(address(this));
    require(amountToSend >= amountTokenMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT_FOT'); // second slippage check
    safeTransferToken(token, address(this), to, amountToSend);
    safeApproveToken(whbar, WHBAR, amountETH);
    IWHBAR(WHBAR).withdraw(address(this), to, amountETH);
    safeDissociateToken(address(this), token);
}
The removeLiquidityETHSupportingFeeOnTransferTokens function operates in HBAR but derives its name from Uniswap on Ethereum. This name was kept to simplify integration for developers versed in Uniswap tools.

​
Code Overview

Resources:
Typescript
import { 
  ContractFunctionParameters, 
  ContractExecuteTransaction,
  AccountAllowanceApproveTransaction,
  .. 
} from '@hashgraph/sdk';

//Client pre-checks:
// - Router contract has spender allowance for the LP token

const params = new ContractFunctionParameters();
params.addAddress(tokenAddress); //address token  
params.addUint256(lpTokenAmountToRemove); //uint liquidity
params.addUint256(amountTokenMin); //uint amountTokenMin
params.addUint256(amountETHMin); //uint amountETHMin
params.addAddress(toAddress); //address to
params.addUint256(deadline); //uint deadline
    
const response = await new ContractExecuteTransaction()
 .setContractId(routerContractId)
 .setGas(gasLim)
 .setFunction('removeLiquidityETHSupportingFeeOnTransferTokens', params)
 .execute(client);
 
const record = await response.getRecord(client);
const result = record.contractFunctionResult!;
const values = result.getResult(['uint']);
const amountHBAR = values[1]; //uint amountETH