Adding liquidity (V1)

Add liquidity to an existing HBAR/token liquidity pool. Outlined below are two methods to add liquidity to an existing pool on SaucerSwap:

Adding HBAR-token liquidity
Adding token-token liquidity

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 limit: 240,000

Parameter Name	Description
address token	EVM address of the token to pool with HBAR
uint amountTokenDesired	The maximum token amount in its smallest unit
uint amountTokenMin	The minimum token amount in its smallest unit
uint amountETHMin	The minimum HBAR amount in its smallest unit
address to	EVM address to receive the liquidity tokens
uint deadline	Deadline 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);

function addLiquidityETH(
  address token,
  uint amountTokenDesired,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
  (amountToken, amountETH) = _addLiquidity(
    token,
    whbar,
    amountTokenDesired,
    msg.value,
    amountTokenMin,
    amountETHMin
  );

  address pair = IUniswapV2Factory(factory).getPair(token, whbar);
  require(pair != address(0), "UniswapV2Router: PAIR DOES NOT EXIST");

  safeTransferToken(
    token, msg.sender, pair, amountToken
  );
  IWHBAR(WHBAR).deposit{value: amountETH}(msg.sender, pair);
  liquidity = IUniswapV2Pair(pair).mint(to);
  // refund dust eth, if any
  if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
}

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

JavaScript SDK

Resources:

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 liquidity = values[2]; //uint liquidity

Adding token-token liquidity

Add more liquidity to an existing token/token liquidity pool. Function name: addLiquidity Recommended gas limit: 240,000

Parameter Name	Description
address tokenA	EVM address of the first HTS token
address tokenB	EVM address of the second HTS token
uint amountADesired	The maximum amount for the first token in its smallest unit
uint amountBDesired	The maximum amount for the second token in its smallest unit
uint amountAMin	The minimum amount for the first token in its smallest unit
uint amountBMin	The minimum amount for the second token in its smallest unit
address to	EVM address to receive the liquidity tokens
uint deadline	Deadline 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

JavaScript SDK

Resources:

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

Next steps

Removing liquidity (V1)

Withdraw your share of a V1 pool.

Create a new pool (V1)

Create the pool first if it does not exist.

Get pool reserves (V1)

Read current reserves before sizing amounts.

Getting started

V1 guides

V2 guides

V3 order book

More guides

Security

AI

Adding liquidity (V1)

Adding HBAR-token liquidity

Code overview

Adding token-token liquidity

Code overview

Next steps

Removing liquidity (V1)

Create a new pool (V1)

Get pool reserves (V1)

​Adding HBAR-token liquidity

​Code overview

​Adding token-token liquidity

​Code overview

​Next steps

Removing liquidity (V1)

Create a new pool (V1)

Get pool reserves (V1)

Adding HBAR-token liquidity

Code overview

Adding token-token liquidity

Code overview

Next steps