Questions tagged [uniswapv2]
The uniswapv2 tag has no usage guidance.
92 questions
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Optimal arbitrage amount between uniswap V2 and V3
since we can get the optimal arbitrage amount by price impact formula between 2 uniswap v2 markets, how could i approach to calculate the optimal amount between an uniswap v2 - with constant product ...
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40
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Uniswap V2 Quoting using reserves - getamountout methods
I have been having abit of issue with quoting on uniswap v2 based exchanges. I am extracting the reserves and using the formula. - univ2_formula = lambda amount_in, in_lq, out_lq: (out_lqamount_in0....
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How to solve invalid input params issue for uniswap v2 router 'addLiquidity' method
Can you tell if I am wrong about any of the arguments used for the addLiquidity. I am using wagmi and ethers.
Error
Caused by: InvalidInputRpcError: Missing or invalid parameters.
Double check you ...
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56
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how do i open trading and sniping/buying token in same bundle
i saw a lot of people launch tokens after adding liquidity to uniswap and then snipe/buy the first few buys as a bundle ( they know in advance how much it will cost them so they disperse x amount of ...
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Uniswap Swapping
I have a problem swapping on uniswap. I want to swap token but when I select token I want to swap it says "not enough liquidity". Can anyone help me. It is quite some money in stake. Thanks.
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I have issues buying Base Coins. Error: Fail with error 'TransferHelper: TRANSFER_FROM_FAILED'
web3= Web3(Web3.HTTPProvider(alchemy))
#print(web3.is_connected())
#Instancia contrato uniswap
uniswap_router_contract = web3.eth.contract(address=botuni, abi=abiBot)
# Crear instancia del contrato ...
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54
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Burn from Uniswap Pool on BUY transaction
I've implemented a smart contract with a burn mechanism triggered after a specific countdown elapsed upon token purchase. Despite successful deployment on the Sepolia testnet and functioning buy/sell ...
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23
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Using FlashSwap with Uniswap swapping functions like 'swapExactETHForTokens'
I tried taking a loan from Uniswapv2 Flash swap. After taking the loan successfully, I tried making a swap on the uniswap v2 using the swapExactTokensForTokens function then I got this error "...
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33
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UniswapV2Router.sol addLiquidity() / UniswapV2Pair.sol mint() - Learning to read code
Can anyone explain to me what I fail to understand/misunderstand when reading the mint function of the UniswapV2Pair.sol contract after the addLiqudity function of the UniswapV2Router.sol initiates a ...
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call function uniswapv2 swapExactETHForTokensSupportingFeeOnTransferTokens return UniswapV2: INVALID_TO
i call the following function in js :
function swapForShare(uint amountOut) public {
uint ethBalanceBefore = address(this).balance;
require(ethBalanceBefore > 0, "Contract ...
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30
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Cannot remove liquidity from Uniswap on Base Chain
I would like to seek assistance for this please. I think the LP for my token broke after renouncing the contract. No one was able to trade after the renounce. will give 0.05 eth to anyone who can help ...
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19
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call swapExactTokensForETH in javascript
I have the following function in JavaScript:
try {
let tx = await router.connect(receiver).swapExactTokensForETH(
tokenAmountToSwap,
0,
[token.address, await router.WETH()],...
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62
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How to precisely remove a specific amount of token0 or token1 liquidity from a Uniswap V2 Pair in Solidity
I need to remove an exact amount of token0 or token1 from a Uniswap V2 pair. To achieve this, I must calculate the amount of LP tokens to burn. The calculation formula is straightforward:
Where:
...
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45
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Is it possible to recover non-reserve tokens accidentally sent to a Uniswap V2 Pair contract?
I'm trying to understand the operation and potential pitfalls of interacting with UniswapV2Pair contracts. I'm aware that if excess token0 or token1 are sent to a Pair contract, it may be possible to ...
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I updated Solidity to version to 0.6.12. Now the code is broken, how to fix?
How can I fix my code, the chainid is 9999.I tried changing chainId := chainid to chainId := chainid() but it doesn't work. Here is the whole code:
pragma solidity 0.6.12;
import './interfaces/...
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27
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uniswap v3 Calculate entrance price of a liqidity pool
for example I have added a liquidity on a uniswap v3 pool with this data:
pair: CAKE-ETH
min price: 1,074.54
max price: 1,118.39
cake amount: 116.752
eth amount: 0.077786
tick spacing: 200
now how ...
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20
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Downscaling liquidity tax according to ETH reserves for fair distribution without presale
So I wanted to try and solve the problems that arise when releasing a token with very low liquidity. Presaling should absolutely be avoided since holders always dump at the start.
Assume 50 to 100% of ...
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46
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reserve0/reserve1 price is different compared to boughtTokensAmount/requiredWeiAmount
I would start with a sample on exact UniswapV2 pair SHIB/WETH (SushiSwap). I use local hardhat node and there's no possibility of 3-rd party effect on LP.
I have this toSwapTokensAmount = ...
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135
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UniversalRouter execution reverteed BASE chain
I'm trying to use UniversalRouter to swap WETH to token, this is how i'm doing it:
//from - WETH, to - test token
const contract = new ethers.Contract(
"...
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1
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48
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transaction reverted when calling swapExactETHForToken on uniswapRouter02
currently, I'm trying to swap eth for an erc20 token and the transaction gets reverted every time, not quite sure what I'm missing, i pre-approved some allowance for the router02 to spend on my behalf,...
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167
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Transaction execution reverted on swapExactTokensForETH
I hope somebody can help
I am trying to sell a token via Uniswap V2 Router02 (Token CA: 0x4ed4E862860beD51a9570b96d89aF5E1B0Efefed) (This token is a legit one, there is no scam here), I have ...
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377
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Insufficient Liquidity after adding liquidity on Sepolia Uniswap V2
I created a token "TestMe" with 2 million tokens (18dec), minting the deployer address the whole stack. I used the "addLiquidityETH" function provided by uniswap router to add 500k ...
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1
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93
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Insufficient Allowance ERC20 when adding liquidity to Uniswap V2 Pool
I am trying to create a contract with a Uniswap V2 Pair for my TestMe Token on Sepolia Testnet.
Smart Contract:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
import "lib/openzeppelin-...
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1
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432
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Uniswap V2 Router, Factory on amoy Test Network
what is the address of uniswap router on amoy test network as currenty uniswap doesn't support amoy network.
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19
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I cant sell this token, me3 contract below, anyway to sell?
/**
*Submitted for verification at BscScan.com on 2024-04-13
*/
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.19;
abstract contract Context {
function _msgSender() internal view ...
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1
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49
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Can someone explain the initialize function in UniswapV2 contract?
https://etherscan.io/address/0x1b5bea98cb56da56723db75f2c3b24f6119faf98#code
function Initialize () external onlyOwner {
require(!tradingOpen,"init already called");
...
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49
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Large price discrepancy between swapExactTokensForTokens and official swap
I am testing performing swaps using solidity ^0.8.24 smart contracts with hardhat on Polygon and Quickswap exchange. But I am getting relatively large price discrepancies between my swap and one ...
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208
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Execution Reverted due to UniswapV2-Pair creation in constructor
I am new to Blockchain development, so bear with me.
I successfully deployed my first contract, but if I try to add a Uniswap V2 Pair creation inside the constructor, I always get the error "...
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2
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193
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UniSwapV2 Testnet Support
As you may be aware, the Goerli Testnet has been deprecated, and furthermore, UniSwapV2 is not supported on the Sepolia Testnet. What would be the recommended solution?
Thank you in advance.
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Optimizing gas consumption for the Spit Swap smart contract
how to optimize gas consumption for Spit Swap? If I use the pool contract directly, can this significantly reduce gas consumption?
SplitSwapV2.sol
// SPDX-License-Identifier: GPL-3.0
pragma solidity &...
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9
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Misalignment between Uniswap V2 calculateSwapInput and calculateSwapOutput functions
I've written my own functions calculateSwapInput and calculateSwapOutput for liquidity pools, based off of the Uniswap v2 spec. My functions are below:
// Calculates how much of one token we need to ...
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2
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91
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uniswapRouter.getAmountsOut returns less value of token B than present in reverses when provide full amounts of token A
I have the next code to get familiar with uniswap mechanics:
create pair contract
get reserves
invoke getAmountsOut and provide all UNI token reserves
const pairAddress = await _V2Factory.getPair(...
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2
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2k
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Does Uniswap allow testing swap on testnets?
I am testing my smart contract on goerli testnet.
Everything is working. After I complete adding an LP when I want to test whether it is able to swap, the system keep showing "Insufficient ...
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41
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Swapping continuouly failing. only one become success with swapExactTokenForTokens
I have this function.I want to perform swap 3 times with the interval of 30 second using swapExactTokenForTokens.But only only one transaction get success.Others failing.
Here is my Code.
const ...
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291
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I am getting reason: 'invalid BigNumber value', Error. What is the reason?
wallet = ethers.Wallet.fromMnemonic(mnemonic)
// console.log(wallet.address)
const signer = wallet.connect(provider);
// console.log(signer)
const routerInstance = new ethers.Contract(routerAddress, ...
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0
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28
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How can Retrieving Pending Transaction Reserves (reserve0 and reserve1) in Uniswap V2?
How can I retrieve the reserve0 and reserve1 values from Uniswap V2, not from already mined blocks, but specifically from transactions that are still pending?
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55
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Unable to Add Liquidity using uni swap V2 front end clone
I’m having error from the Uniswapv2 clone that I cloned following the below website instructions:
https://www.covalenthq.com/docs/unified-api/guides/how-to-clone-uniswapv2-frontend/
The problem I’m ...
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Liquidity pool question (probably very dumb)
My company launched an ERC20 with a Uniswap LP a few years back (2020). They never did anything much with it, and now they want to pull the LP and be done with it. The problem is that nobody in the ...
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Uniswap V2 optimal arbitrage amount
Tried out whole week to find an answer somewhere for this question, but, nothing to see, unfortunately,
Let suppose there are 2 USDT/WETH pairs, one on Uniswap and another one on any Uniswap v2 fork ( ...
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337
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How can I run the Uniswap Dapp locally for sepolia testnet
I am trying to play around with the Uniswap contracts, by creating pools then swapping etc. The problem I'm facing is that Uniswap V2 doesn't support the sepolia network, V3 does.
So when I interact ...
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206
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Trouble making UniV2 swap on Sepolia with web3py
I'm using the below code to try and make a swap on Sepolia. I've got ETH in my wallet and have found a token that has had liquidity added. Depending what I set the minOutput to I get 'Fail with error '...
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130
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Python Web3 sign transaction without calling "build_transaction"
I need to sign two different transactions:
token_contract = web3.eth.contract(address=web3.to_checksum_address(TOKEN_ADDRESS), abi=json.loads(erc20_abi))
approve_trx = token_contract.functions.approve(...
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Vulnerable when using swapExactETHForTokens
I thought that setting block.timestamp to a deadline prevents MEV sandwich attacks.But my question is does it do the work well?
address destinationAddress,
uint256 minAmountOut
) ...
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What happens when we directly send tokens to Uniswap pair?
This is about Uni V2 pools.
So usually we call the function addLiquidity to add liquidity, but the function decides how many tokens should be added depending on the reserves.
What if we directly send ...
- 115
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326
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getAmountIn equivalent of uniswapV3 or how to calculate it?
I was exploring uniswap V3 router, quoter and factory contracts, but it doesn't have getAmountIn function to calculate the minimum amount I must input to get the desired amount. On some thread, I ...
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40
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Uniswap/PancakeSwap automatically manage tokens with different amount of decimals (swap)?
I'm getting number results that do not make sense for me, when executing swap functions with USDT (in Uniswap V2 and PancakeSwap V2), and I noticed that USDT Token has only 6 decimals, instead of 18 (...
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47
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what will happen when two people execute removeLiquidity in uniswap v2?
According to the code of uniswap-v2/v2-periphery/contracts/UniswapV2Router02.sol in function removeLiquidity():
// **** REMOVE LIQUIDITY ****
function removeLiquidity(
address tokenA,
...
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0
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267
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cannot use array as type ptr as argument
I am using Go-Ethereum and I have the following error:
abi: cannot use array as type ptr as argument
But it does not make any since I don't pass an array.
The arguments to routerABI.Pack function ...
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2
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355
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How to know base token from the pool
here is quick question. From uniswap pool, which one is base token? token0 or token1?
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2
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4k
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Getting Uniswap v2 latest price and interpreting values using Python
When interacting with functions price0CumulativeLast and price1CumulativeLast of any smart contract on Uniswap V2 I keep getting incomprehensive values. I am not able to figure out how to extract the ...
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