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Questions tagged [erc-20-approve]

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12 votes
4 answers
6k views

Is it possible to batch approve + transfer an ERC-20 token?

In our dapp, we currently have the following user flow: Approve the Sablier contract to spend up to x ERC20 tokens Transfer the x ERC20 tokens to the Sablier contract This is not super bad UX, but ...
Paul Razvan Berg's user avatar
1 vote
3 answers
5k views

IERC20.approve(spender, amount) thinks the owner is also the contract

I have these functions and deployed my contract to Ropsten testnet. function setSmartContractAllownace(uint daiAmountIn) public { IERC20 daiToken = IERC20(ropstenDAI); daiToken.approve(...
Saehun Sean Oh's user avatar
0 votes
1 answer
510 views

Can Metamask be used for all ERC20 token?

How can I use WETH with Metamask wallet? I can see ETH in my Metamask (Rinkeby TestNet, it works on Mainnet) but can not use other tokens. Any Repository or lead will be appreciated. If yes, What will ...
Rohit Mittal's user avatar
4 votes
2 answers
14k views

What is the use case of transferFrom function in ERC20 token contract?

In @openZeppelin's ERC20 implementation here is the code for function transferFrom: function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) { ...
user938363's user avatar
2 votes
1 answer
3k views

"gas estimation failed" error using Uniswap. Can't fix it, please help

I can't sell alt-tokens back into ETH. This is an issue with multiple tokens, not just one and they all have very high liquidity ($Kabosu and $OHMI). I immediately get the error 'gas estimation failed'...
UniSwapper's user avatar
2 votes
1 answer
1k views

Fail with error 'TransferHelper: TRANSFER_FROM_FAILED' Although approved

I'm trying to make a swap programmatically, I did the following approvals using ethers.js: token0.approve(wallet.address, amount); token1.approve(wallet.address, amount); token0.approve(...
0x_Anakin's user avatar
  • 121
1 vote
1 answer
948 views

How to make a delegatecall to external ERC20 token's approve function?

What I would like to do is something like this: function testCall(uint amount) public virtual returns (bool) { address tta = address(0xE7B6....); (bool success, bytes memory result) = tta....
Damir Olejar's user avatar
1 vote
1 answer
3k views

Contract with function payable to receive ERC20 token in one shot?

I am trying to write a smart contract with a function that receives an ERC20 token (i.e.: DAI), but the transaction to call this function is always failing. Let's assume I first record the ERC20 ...
Sergi Juanati's user avatar
0 votes
2 answers
2k views

Failing to trying to approve contract using ethers.js (CALL_EXCEPTION or cannot estimate gas)

I am having trouble calling a simple ERC-20 approve function from the front end on the Arbitrum network. Any insight is greatly appreciated. I will outline my code below. I am retrieving the provider ...
qoze's user avatar
  • 13