Hi guys, can anyone please explain in layman terms about what an ERC777 token is? How is it different from ERC20?

It adds extra features which enhances erc20

that is there are operators

who can act on behalf of the token holder or contract

function defaultOperators() external view returns (address[] memory);
function isOperatorFor(
address operator,
address holder
) external view returns (bool);
function authorizeOperator(address operator) external;
function revokeOperator(address operator) external;

but its adoption is very low

as operators such as defaultOperator when not set to 0x0 or nobody can do harm to all the holders

they can send anyone's token

burn anyone's token

or even spend anyone's token

So basically, it's a role that everybody has approved without actually approving, correct?

The defaultOperator yes

but user can approve other operators

That does sound a very attractive feature.

Yes, thats the most riskiest part

Best difference I saw is the token fallback implementation

nope very risky if not set to nobody, why must deployer have control over someone's token

In DApps, I bet there must be one contract every new user would have to approve using ERC20.

In ERC777, if this smart contract is set as the operator, that does save many approve function calls, no?

Not every one needs that

Also check permit which dai and uniswap uses for gasless approval

There is a reason the big dapps didn't opt to use that eip

I don't see a fallback implementation in ERC777.

I noticed this, and wonder who pays the gas fees then.

I understand the caller does not pay for gas fees, and when the signed messages are executed, the receivers pay the gas fees?

I also looked into it when I was building my token, I later ignored it

dai and uniswap pay the fees?

Nono

User

See let's say you want to call a method called deposit

you will add the signed data to the deposit function, then you will permit from deposit function

So indirectly when user calls deposit, he pays for the gas but it's a one call instead of

Approve and deposit

I think what you are saying is permit here: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/extensions/draft-ERC20Permit.sol

Yes

There is one, you may have missed it. There is also a registry, which keeps record of all the tokens deployed as erc777

I know but consider the extra gas involved

I read somewhere that it has a gas issue

I think this is the fallback function in your mind, but it is called a different name: _callTokensReceived

You may check the function definition🙂

tokensReceived()

Its not a unique feature of 777, was proposed in 223 or something. But looks neat

That would be something all erc20 must have

The callback

It is a similar implementation to IERC165 and ERC721.

All those lost tokens in contracts...

Works for my dapp though

approve and transfer does take two steps, however, once an address is approved with a very high allowance, all future transactions take a much simpler one step, transfer. permit is a big one step across the life time of the token.

There is a trade-off to consider.

https://github.com/ethers-io/ethers.js/issues/814

Try upgrading ethers to 5.xx

Does anyone know or have practical experience with MiniMeToken contract? I think it was an interesting idea.

PCS is a fork of uniswap v2, so if its the swap you need go to uniswap

besides what are you facing with pcs code

these are basic stuff