tl;dr
Perpetual Protocol products only use USDC.e as of Q4 2023. If you have USDC issued by Circle (the new USDC token on Optimism), you'll need to swap it for USDC.e on Uniswap or other DEXs before using any Perpetual Protocol product.
Will the real USDC please stand up
Mid-way through 2023 USDC issuer Circle announced they would be launching new USDC tokens to replace USDC on chains like Optimism, NEAR and Polkadot.
We won't speculate as to why but those original tokens typically were bridged from Ethereum or elsewhere and the token contracts were not controlled by Circle itself. The new USDC token brings these contracts under Circle's control.
Ok now what
As of this writing, neither Circle nor Optimism have made any statements announcing a timeline for migrating away from USDC.e on Optimism. So it would seem that USDC.e use will continue for some time.
Most Defi protocols using Circle's stablecoin, including Perpetual Protocol, use USDC.e, and we expect this to remain the case for current versions of our products, such as Perp v2 and Hot Tub.
Where to swap
USDC and USDC.e are easily swappable on Uniswap and other DEXs. If a Perpetual Protocol product does not recognize your USDC balance, you most likely have USDC and need to swap for USDC.e.
Contract addresses
Token contract addresses on Optimism are as follows:
USDC: 0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85
USDC.e: 0x7f5c764cbc14f9669b88837ca1490cca17c31607