Add liquidity to an existing HBAR/token liquidity pool.

Outlined below are two methods to add liquidity to an existing pool on SaucerSwap:

Contract ID: SaucerSwapV1RouterV3

To create a new liquidity pool, see Creating a new liquidity pool.

Ensure that the client has the LP token associated before adding liquidity.

A spender allowance for the Router contract is required for HTS tokens.

Both addLiquidityETH and addLiquidity support HTS tokens containing custom fees.

​
Adding HBAR/Token Liquidity

Add more liquidity to an existing HBAR/token liquidity pool.

Function name: addLiquidityETH

⛽ Recommended gas: 240,000 gwei (~ $0.020 USD)

Parameter NameDescription
address tokenEVM address of the token to pool with HBAR
uint amountTokenDesiredThe maximum token amount in its smallest unit
uint amountTokenMinThe minimum token amount in its smallest unit
uint amountETHMinThe minimum HBAR amount in its smallest unit
address toEVM address to receive the liquidity tokens
uint deadlineDeadline in Unix seconds
function addLiquidityETH(
  address token,
  uint amountTokenDesired,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);

The addLiquidityETH 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,
  TokenAssociateTransaction,
  .. 
} from '@hashgraph/sdk';

//Client pre-checks:
// - Output NFT token is associated
// - Router contract has spender allowance for the input token

const params = new ContractFunctionParameters();
params.addAddress(tokenAddress); //address token
params.addUint256(amountTokenDesired); //uint amountTokenDesired
params.addUint256(amountTokenMin); //uint amountTokenMin
params.addUint256(amountHBARMin); //uint amountETHMin
params.addAddress(toAddress); //address to
params.addUint256(deadline); //uint deadline
    
const response = await new ContractExecuteTransaction()
 .setPayableAmount(inputHbar)
 .setContractId(routerContractId)
 .setGas(gasLim)
 .setFunction('addLiquidityETH', params)
 .execute(client);
 
const record = await response.getRecord(client);
const result = record.contractFunctionResult!;
const values = result.getResult(['uint','uint','uint']);
const amountToken = values[0]; //uint amountToken
const amountHBAR = values[1]; //uint amountETH
const liqudity = values[2]; //uint liquidity

​
Adding Token/Token Liquidity

Add more liquidity to an existing token/token liquidity pool.

Function name: addLiquidity

⛽ Recommended gas: 240,000 gwei (~ $0.020 USD)

Parameter NameDescription
address tokenAEVM address of the first HTS token
address tokenBEVM address of the second HTS token
uint amountADesiredThe maximum amount for the first token in its smallest unit
uint amountBDesiredThe maximum amount for the second token 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 liquidity 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);

​
Code Overview

Resources:

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

//Client pre-checks:
// - Output NFT token is associated
// - Router contract has spender allowance for the input tokens

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('addLiquidity', params)
 .execute(client);
 
const record = await response.getRecord(client);
const result = record.contractFunctionResult!;
const values = result.getResult(['uint','uint','uint']);
const amountA = values[0]; //uint amountA
const amountB = values[1]; //uint amountB
const liquidity = values[2]; //uint liquidity