Questions tagged [openzeppelin-contracts]
OpenZeppelin Contracts is a library for secure smart contract development. It provides implementations of standards like ERC20 and ERC721 which you can deploy as-is or extend to suit your needs, as well as Solidity components to build custom contracts and more complex decentralized systems.
253
questions
0
votes
0
answers
7
views
Trouble with Solidity Compiler Version when combining Aave and Openzeppelin in Foundry
I'm trying to follow this tutorial by Patrick Collins on Flashloans but in Foundry: https://www.youtube.com/watch?v=Aw7yvGFtOvI&t=328s
When in try to forge build I get the following error:
: src\...
- 11
0
votes
1
answer
20
views
Private variables with public view functions
In the Openzeppelin ERC721.sol contract, there are private variables introduced:
// Token name
string private _name;
// Token symbol
string private _symbol;
These variables are then assigned a ...
- 81
0
votes
0
answers
23
views
OpenZeppelin Context.sol, when to use & why?
When, and why is it better to use functions _msgSender() & _msgData() introduced by the Context.sol by OpenZeppelin, instead of msg.sender & msg.data?
- 81
0
votes
3
answers
29
views
Is automating the withdraw of a NFT smart contract a good idea? [closed]
Just wondering out ! Something like automatic withdraw after every 24 hours or something like withdraw after every mint on the contract.
If its a good idea, sharing any ways or resources for me to do ...
0
votes
2
answers
38
views
Function Max mint per wallet is not working
learning solidity and curious how i can limit the minting of my NFT to only 2 per wallet address. Trying to prevent people from minting more then 2 tokens during free mint phase using "mapping&...
- 11
3
votes
1
answer
34
views
Call smart contract function from another smart contract
I am new to Solidity and I'm having some trouble when calling a function of a smart contract from another one.
Basically I have smart contract A, which extends ERC20 and the Ownable contract from ...
- 33
1
vote
1
answer
39
views
Initializing the implementation contract when using UUPS to protect against attacks
In OpenZeppelin's documentation, it's mentioned that we should be invoking the _disableInitializers function, otherwise our contract might be vulnerable to certain attacks. Can someone explain how ...
- 135
1
vote
0
answers
29
views
Deploy Upgradable contract with factory contract
I have a simple contract below Swap.sol that is upgradable.
// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.4;
import "@openzeppelin/contracts-upgradeable/proxy/utils/...
- 73
0
votes
2
answers
49
views
ERC777 upgradeable deployment error: cannot estimate gas; transaction may fail or may require manual gas limit hardhat
Hi I could not deploy my ERC777 Upgradeable contract into Hardhat test network.
My ERC777 contract:
pragma solidity ^0.8.15;
import "@openzeppelin/contracts-upgradeable/token/ERC777/...
- 1,460
0
votes
2
answers
39
views
How do you pass in a variable as a string to a constructor in solidity
I'm currently working on an NFT project, using the openzeppelin ERC721 standard for the nfts.
When Inheriting the ERC721 NFT contract standard from openzeppelin you're required to pass in the "...
0
votes
0
answers
31
views
TransferFrom Error - "not visible after argument-dependent lookup in contract Token"
I'm calling a transfer, transferfrom, approve contract following the open-zeppelin ERC20 source.
I got not found issues. Maybe I'm omitting something.
My Code:
token.sol
//SPDX-License-Identifier: MIT
...
- 3
0
votes
1
answer
35
views
In My ERC-721 Contract, tokenURI Doesn't Return A String, It Returns A Promise
In my solidity contract, the function for tokenURI looks like this:
function tokenURI(uint256 tokenId)
public
view
virtual
override
returns (string memory)
{
require(
_exists(tokenId),
...
- 191
0
votes
1
answer
116
views
Does a minimal proxy contract that creates clones need an upgradeable smart contract
I want to understand a few things regarding the implementation of clone factory pattern in smart contract. Do we need an upgradeable smart contract to implement the cloning mechanism (the clones ...
- 812
0
votes
1
answer
21
views
OpenZeppelin Contracts
https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol
Why functionCall calls the other functionCall ?
I don't understand why they do nested callings instead of ...
0
votes
0
answers
20
views
Transactions reverting
So the thing is I am trying to make a smart contract with multi sig. However, it's showing this error when I am trying to transfer ownership:
Transaction would revert. Check that permissions, ...
- 1
0
votes
1
answer
22
views
Can we assume that IERC20Metada will work with every ERC20 token?
I'm developing a contract that receives ERC20 tokens and need to know token name and token symbol.
According to the IERC20 in OppenZeppelin there is no public symbol() or name() functions. I know that ...
- 705
0
votes
1
answer
36
views
Gas optimisation: maximum of two numbers
Any ideas if I can optimize the gas of the following function from Math library of OZ:
function max(uint256 a, uint256 b) public pure returns (uint256) {
return a >= b ? a : b;
}
*I checked ...
- 15
0
votes
0
answers
26
views
Upgrade a contract mapping struct
I have an upgradable contract (openzeppelin):
contract MyContract is OwnableUpgradeable {
...
struct MyStruct {
uint a;
uint b;
}
...
mapping(address => ...
- 101
0
votes
0
answers
68
views
EscrowUpgradeable triggers "Ownable: caller is not the owner."
I am newbie and am on Truffle/Openzeppelin stack.
I am following the example/tutorial for Using Escrow Library at https://medium.com/@ethdapp/using-the-openzeppelin-escrow-library-6384f22caa99
and all ...
- 103
0
votes
0
answers
32
views
Deploy a crowdsale contract for a previously deployed ERC20 token
I have deployed an upgradable ERC20 token using ^0.8.4 and I would like to set up an AllocatedCrowdsale from OpenZeppelin for said token. I have set up a second project for the crowdsale using ^0.5.0 ...
- 1
1
vote
0
answers
285
views
Error: missing revert data in call exception on tokenOfOwnerByIndex and tokenByIndex from openzeppelin ERC721Enumerable
I'm getting a odd error across several calls out to openzeppelin that
Error: missing revert data in call exception; Transaction reverted without a reason string
I didn't change anything and am using ...
- 123
0
votes
0
answers
59
views
How ERC 1155 standard prevents from "out of gas" error in batch operations?
I was checking the implementation of Openzeppelin's implementation of ERC-1155 standard and I'm curious about the use of _safeBatchTransferFrom function to transfer multiple tokens at once. The ...
- 705
0
votes
0
answers
11
views
Can I use Crowdsale with ERC20 Token created in OZ4.5.0?
Basically, I already have ERC20 token created, which is using solidity 0.8.2 and OpenZeppelin version 4.5.0. I know that Crowdsales supports only OpenZeppelin Contracts 2.x version. I am not sure if I ...
- 1
0
votes
1
answer
684
views
function selector was not recognized error
I'm extending OpenZeppelins ERC20 to create a Token that I use for testing in another smart contract. Here's how it looks:
//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;
import "@...
0
votes
2
answers
58
views
Sending ERC20s to a Contract on deployment
I'm trying to send an amount of ERC20 on Contract deploy to the contract itself. I'm using Hardhat and OpenZeppelin Contracts.
Contract Code:
//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8....
0
votes
0
answers
41
views
If I use the cloning pattern to launch erc721s, will it list on exchanges like a normal contract?
Hey I'm looking at implementing a basic minimal clone of an ERC721 contract (using the openzepplin cloning implementation), and I was wondering if it would make any difference in how the tokens are ...
0
votes
0
answers
153
views
Can't import OpenZeppelin Ownable contract
I'm following freecodecamp's solidity course but am unable to import Ownable from OpenZeppelin into my contract.
Using brownie, this is what I have so far:
and in the config.yaml file:
And when I ...
- 1
0
votes
1
answer
73
views
Referencing OpenZeppelin in Solidity Contract, working with Etherscan
I think I am making a simple mistake, but I have been stuck for a while.
I have a simple ERC-20 contract which I have publish on the Ethereum Mainnet and others on Polygon.
This is a sample contract ...
- 105
0
votes
1
answer
295
views
upgradeble openzeppelin contracts - why the __gap is needed if you can add variables to the end?
https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
1: https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps explains why the __gap variable is needed, but https://docs....
- 113
1
vote
0
answers
102
views
Solidity Advanced Transparent Proxy pattern
Proxy contract - The contract users are calling to use current implementation
Admin Proxy Contract - Contarct to Update Current Implementation or current Structure Model
Implementation Contract (where ...
- 11
0
votes
1
answer
108
views
Imported Openzeppelin contract is different than on GitHub
I am trying to import the ERC2981.sol from the OpenZeppelin contracts repository. In their GitHub page the royaltyInfo is a public function. But for some reason when I import it in my project, this ...
- 138
0
votes
0
answers
286
views
How to burn erc721 token?
I am trying to burn erc721 token. I have inherited ERC721Burnable contract,but the transaction gets failed.While debugging I found that in ERC721URIStorage contract,it reverts back at:
if (bytes(...
1
vote
1
answer
217
views
How to test recoverSigner and splitSignature
I am currently trying to test a function that uses a recoverSigner inside and I'm not sure how to proceed. Here is the function:
function claimToken(bytes32 message, bytes memory _signature, address ...
- 128
1
vote
0
answers
56
views
Openzeppelin ERC1155 missing virtual function?
This is my ERC1155 contract:
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;
pragma abicoder v2;
import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
contract ...
- 33
0
votes
1
answer
336
views
How to use ERC721URIStorage and ERC721Royalty together (requires override)
I am initializing my contract as below:
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";...
- 138
1
vote
0
answers
321
views
Transparent proxy tests - Error: missing revert data in call exception; Transaction reverted without a reason string;
I am trying to create a new token contract using the ERC20 Upgradeable contracts provided from Openzeppelin (OZ). I created the token contract and then made some basic unit tests. However, in one of ...
- 21
0
votes
0
answers
82
views
Approve and dis-approve ownership of erc721 tokens
I have created a contract which takes care of buy and sell of NFT's or ERC721 tokens. So i have approved the contract to sell the NFT. Now my questions are:-
Once I have transferred the contract to a ...
- 101
0
votes
0
answers
573
views
nft images not showing on opensea
I created 13 images and corresponding JSON files uploaded the images to pinata then changed the file_url in the JSON file to cid of the image "ipfs://cid/image.png"
uploaded the json file as ...
- 11
0
votes
0
answers
33
views
Getting an error when I try to create a ERC20 token from another contract
I'm trying to create an upgradeable ERC20 contract from a Factory but I'm receiving an error, these are my contracts:
The token contract
// SPDX-License-Identifier: MIT
pragma solidity 0.8.7;
import &...
- 135
0
votes
0
answers
48
views
How can I create a factory of Upgradeable smart contracts?
I'm using OpenZeppelin hardhat plugin to deploy proxy contracts and I was asking myself how to achieve the same thing but from a contract. So for example I want to have a ProxyContractFactory that can ...
- 135
0
votes
2
answers
203
views
Solidity: Contract should be marked as abstract
I am trying to write a Smart Contract to generate Staking Rewards for an existing Cryptocurrency
But I've been getting this error
Contract "Stakeable" should be marked as abstract
How do I ...
0
votes
0
answers
46
views
Upgreadable ERC20 address cannot be passed as argument in another upgradeable contract
I created 2 smart contracts.
contract A is ERC20 token and B is a contract that accepts ERC20 A as payment method. When deploying, contract A got deployed but when I passed the address where it was ...
0
votes
1
answer
110
views
I can't deploy my Upgradeable contract using truffle plugins
I'm trying to deploy the following smart contract:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
...
- 135
0
votes
0
answers
173
views
Upgrade ERC721 Contract
I've a question about an upgrade that I should apply to a contract that I deployed as upgradable (with openzeppelin Upgradable).
I'm following the guidelines and best practices but I'm not sure the ...
0
votes
1
answer
409
views
Deploy a contract passing data to the constructor
I'm trying to get familiarised with OpenZeppelin upgradable contracts but I find it difficult because there are not clear tutorials on how to do this kind of things so I'm using their docs to try to ...
- 135
0
votes
1
answer
111
views
Ownable Minimal Proxy (EIP-1167)
I'm trying to create a clone from a contract that has some privileged functions and inherits from Ownable.
I realized that after cloning the owner variable is zeroed, so any privileged function, such ...
- 63
0
votes
1
answer
210
views
What's the point of OpenZeppelin Counters library
I've been studying ERC721 token smart contracts and saw Counters library.
I can see it being used when token is being minted with .increment() and then you can check total supply with .current(). But ...
- 103
0
votes
1
answer
488
views
EnumerableSet vs Access Control in Openzeppelin
Openzeppelin offers RBAC whereby an address may be granted a specific set of responsibilities.
I would like to know which might be considered a better practice - using Access Control Or using an ...
0
votes
1
answer
223
views
How to Use OpenZeppelin's ERC721Votes in an NFT Minter Contract
I'm trying to incorporate the new draft-ERC721Votes in my NFT minter contract called NFTVotes.sol
When draft-ERC721Votes.sol is inherited in the minter contract, VS Code is gives the following error:
...
- 103
0
votes
0
answers
103
views
Lazy minting multiple NFTs belonging to a collection
in my project right now we have implemented lazy minting using signed voucher messages
the signer of which gets verified on chain and hence letting the purchaser pay for the gas fees of minting the ...