ERC-6909-multi-token-standard

ERCs
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62

if the wording is kept, then definition would be “no supply”

re rm “should”: do you think the statement should be replaced with something else like “must” or just remove it altogether?

63

I’d remove them altogether (talking about “should return 0/empty string”).

1 Like
64

I’m preparing an ERC draft for the extension I shared above (ERC-6909 Usability & Security Extensions).

I have a question about compliance: if a token does a temporary approval or sets a temporary operator that resets at the end of the function call, is it necessary to emit the Approval or OperatorSet events?

Argument for emitting: an indexer might break if it sees a “transferFrom event” without the corresponding allowance or operator status. Argument for not emitting: significant gas savings (at least one fewer event, possibly two), and there is no need to track the action in an indexer anyway because the value is set transiently.

I would prefer not to emit the event(s) but the ERC states:

Approval MUST be logged when the allowance is set by an owner.
OperatorSet MUST be logged when the operator status is set.

The fact that the values are set transiently feels like a significant change that may justify a lack of events.

CC: @jtriley-eth

Edit: I am realizing the ERC is still technically in Draft status. It could be interesting to encode these relaxed rules in the ERC if the authors are open to it. Namely, that the events may be omitted if the values are only set transiently.

2 Likes
65

good catch. i think it could use a little rewording

thinking we make allowance and isOperator storage variables explicit in event log conditions, so since transient approvals don’t mutate these storage variables, there’s no need to log the event

defs leaning into the ‘no transient logs’ camp since the transient variables being dropped at the end of the transaction would also require an event

though mention of transient variables in the spec may be useful as well

66

The spec should try to be implementation agnostic, so I wouldn’t do it this way.

That said, after thinking about this a bit more I realized that omitting these events may mess up allowance indexers, which we previously said were a Good Thing. So I would make the event optional but recommended in these cases, so it’s up to the implementer to take the risk or not.

Perhaps something like this…?

OperatorSet

MUST be logged in a transaction that results in a change of operator status.
SHOULD be logged for transient changes within a transaction. If omitted, offchain indexers may underestimate allowance.

Approval

MUST be logged in a transaction that results in a change of allowance, unless it was caused by transferFrom.
SHOULD be logged for transient changes within a transaction. If omitted, offchain indexers may underestimate allowance.

67

@jtriley-eth Small nit but in the Metadata Extension you have:

name

The name of the contract.

symbol

The ticker symbol of the contract.

Given that there’s an id input argument, I assume these should be the name and symbol of the given token, not the contract.

68

In the section on “backwards compatibility” it says a wrapper can be implemented for ERC-20.

Is my understanding correct: the idea here is that the ERC-6909 contract would have the ERC-20 methods added, so that it appeared to be a normal ERC-20. However, the methods would all be interacting with just ONE of the collection of ERC-20s that live inside the ERC-6909.

69

Great ERC draft. Few comments.

  1. It could be clearer if the token must implement ERC-165. If the intention is that the token must implement it, please add it explicitly into the proposal. If not, I would argue that it should be included as it’s the most convenient way how to discover tokens transfer functions. ERC20 doesn’t have it, and it’s a big pain for protocols working with several token standards at the same time.
  2. I would vote for removing the transfer function and keeping only transferFrom. Any protocol where transfer logic is independent of transfer implementation (e.g., transfer this asset to this address, not knowing who the operator is) will have to perform the check either way, wasting gas savings from keeping both functions.