[SilasX]

Yes! I got burned by Optimism in another way. They tell you to point your applications at etherscan.io for transaction data/history, but then, on November 11 last year, the pushed an update that deletes all transaction history up to that point, which you need for taxes!

They swore they'd have the history restored on Etherscan by Nov 18th, but they still haven't. Only recently they pushed a workaround that lets you download the transactions as a CSV, but that lacks the critical data from your transfers of non-ETH tokens. And then, an alternative source does have that data, but only as a binary blob you have to run through a decoder and parse out yourself.

The crypto tax software, of course, doesn't know what to do with it.

(Even if your local client cached the transactions, most, like MetaMask, left out the critical data above.)

68 days till the filing deadline in the US!

I asked the maintainers how they planned to do their own taxes, and one of them claimed that he was separately recording all sales in a spreadsheet. I had to inform them that the taxable events include more than just sales, and, even under the most aggressive interpretation of tax law, you need the other data to figure cost basis.

[3np]

Let this be a lesson: Maintain local self-hosted copies of any necessary data, don’t rely on third-parties maintaining it and keeping it available. Should be standard practice for anyone doing anything serious with cryptocurrencies but unfortunately users seem complacent enough that easily accessible tooling is still lacking in many places and you may have to DIY scripts for some parts.

Your situation is unfortunate but it sounds like no fault on Optimism or Etherscan here.

(BTW just to be clear: you’re talking about off-chain data that was never part of on-chain txes, and this binary blob comes from some Optimism operator? If it’s on-chain data its just a matter of doing the right queries)

[SilasX]

Okay... in a sense, yes, in hindsight, I should have planned for this. But there are a number of reasons I think this kind of response is too dismissive.

First of all, no matter how well you prepare, there is always going to be one level higher of system failure that you "should have planned for". In the npm-Linux-box-borking debacle, there were people insisting you should never have run npm except on fully disposable hardware with an instantly replaceable dev environment (which is the only thing that would have let you shrug it off).[B]

Got mugged walking home? Should have taken a safer route. Took a safe route? Should have walked with a friend. Still got mugged? Should have walked with two friends. For all n, should have walked with n+1 friends.

Second, it's painting with a tad broad of a brush to call me complacent on crypto. I've filed crypto taxes since 2017 and kept cost basis records from years before. I'm aware systems fail and (outside of this) have set appropriate backups and cached critical transactions to spreadhseets. Even here, even with nothing done by the Optimism team to correct their mistake, I'm not actually doomed, as I can file taxes based on an input-output analysis of my Optimism transactions as a good enough first pass, and correct later. The issue is unnecessary convenience.

In fact, as things stand today, I'm in exactly the "safe" position you thought I was -- "oh, it's there, you just have to query right". Indeed I do! Now that I've pulled the tx data from the alternate sources, I "just" have to yak-shave out a meaningful read of all the transactions. (Update: per sibling, you can download the transactions from a different tab but you still have to do some transformation.) But none of that takes away from the point that this is huge, avoidable inconvenience and flaky community relations.

Remember, even if I had cached them, I'd still be stuck having to manually import them into my crypto tax software, which is a failure from usability.

Third, there are reasons to expect optimistic.etherscan.io as a reliable source to point to.

1) When you set up e.g. Metamask, the Optimism site gives you exactly one URL to point to, with no alternatives or warning that one day it might be missing history. [A] The very fact that Metamask equates "nothing from that url" with "no transactions" means they were treating it as mission-critical.

2) The entire ETH community outside of Optimism relies upon etherscan.io for most of their own tooling ethereum projects. All sources for ETH projects say to connect there, as if it's inconceivable that there could be an outage or need for some fallback.

3) It would have been trivial to keep the transaction history up. There was already a server somewhere (etherscan-owned or otherwise) serving transaction history. All they had to do was configure it to be able to check transactions for being from before that switchover, and ping that (static) DB for a subset of them.

(Remember, this isn't, at least so far, an issue of cost: they do plan to get optimistic.etherscan.io back up as a reliable endpoint for the pre-upgrade txns, they just didn't think to upgrade a way that would facilitate such queries of already-existing immutable data.)

And, for the final kicker.

4) Optimism maintainers themselves didn't even think to locally cache all the transactions they'd need! (As in the one mentioned who only logged a proper subset of taxable events.) If the very people who live and breathe this stuff overlooked it, I think I can be forgiven for overlooking it, as they expect even casual users to join.

[A] https://metamask.zendesk.com/hc/en-us/articles/4403700785691...

[B] https://news.ycombinator.com/item?id=16438630

[EGreg]

You are right. Putting the responsibility on individuals and small organizations is asking for trouble.

But instead, capitalist society simply VC-funds a bunch of centralized entities that wind up with the solution, and don't give it to anyone else. Because after the IPO, Wall Street quarterly earnings demand that it extract rents forever, and you can only do that with closed source software.

Perhaps Web3 and Web4 will finally fix this situation. Open source protocols that can be monetized with cryptocurrency. Filecoin is a good example. It "just works". It may be slightly more expensive than AWS, but can become as resilient as you want.

[kfichter]

Heyo, chiming in from the Optimism team here. You should be able to get non-ETH token transfers (ERC20 or ERC721) via the Etherscan CSV export feature. You may have to make a dummy ERC20/ERC721 transaction to get the page to show up. If that isn't working for you, feel free to hit me up on Discord (I think we already have a thread together) and I can help get you whatever data you need.

See this random account for an example of exporting ERC20 transactions: https://optimistic.etherscan.io/address/0x9c1e0c67aa30c063f3...

[jkhdigital]

> The crypto tax software, of course, doesn't know what to do with it

I’m still trying to calculate proper basis and gains on transactions from 2018… tens of thousands of trades in various complex hedges across 7-8 different exchanges. I just aggregated everything in a single line item on my original return but of course I got audited T_T

[sizzle]

Were they on dexes or cexes? If centralized, don’t you get Tex reports? If not centralized, how will they ever know the extent of the trades?

[leppr]

If the history is completely gone, your government won't be able to find it either, so you can just fill in whatever you want to explain how balance A became balance B.

[AlexCoventry]

Of course it's not completely gone. Chain analysis companies, which tax authorities consult, will have backup copies.

[EGreg]

Wait, what do you mean? I can see all ERC20 transactions in our token (and others) from before Nov 2020

[SilasX]

I'm talking about the record on optimistic.etherscan.io, which they tell you to point to as the definitive blockchain for Optimism. I am looking at my transaction history right now, and it does not show any history from then in the human-readable part of the site.

They recently updated it so you can download a CSV with history from before then (but otherwise no interoperability with the interfaces ETH clients expect).

You're probably looking at a client's local cache of transactions (which I have as well), which doesn't help, since they have limited info within a transaction, and depend on you going to (you guessed it) the etherscan endpoints to see the rest.