Don’t send Mainnet USDT to Immutable V2.1 Splits

TLDR: No user funds have been lost. Don’t send Mainnet USDT to immutable V2.1 Splits. V2.2 will ship next week.

What happened?#

In February, we announced an issue distributing Mainnet USDT in immutable V2 Splits and shipped V2.1 to address it. V2.1 fixed the immediate bug and passed our Foundry Mainnet fork test, but we failed to notice it did so by burning over 60m gas. Thus, in production, V2.1 cannot distribute Mainnet USDT (L2 USDT remains unaffected). Split owners can still resolve the issue, but immutable V2.1 Splits cannot be fixed.

What has Splits done?#

For existing V2.1 Splits, we’ve added prominent warnings in the app and docs, and we are now broadcasting this message as widely as possible. We have filed a bug report with Foundry and are shipping V2.2 next week.

What should I do?#

First, if you expect to receive Mainnet USDT to an immutable Split, double-check that your Split in question is impacted by visiting our UI.

If your Split is impacted, immediately inform any relevant parties not to send Mainnet USDT to it in the future. If your Split has an owner and you would like to continue using it, please read this help center article to fix it.

If you’re a developer relying on our SDK (V4) and creating immutable V2.1 Splits on Mainnet that might receive USDT, please upgrade next week when the new version is released. If you’re using an older version of the SDK that creates V1 Splits, you are unaffected.

What next?#

To be very clear: this outcome does not meet our internal bar for Excellence. We should have 1/ noticed and investigated the absurdly high gas cost of the passing test, and 2/ tested in production as another layer of security. We will ship V2.2 next week to fix this, and as always, we appreciate your support.