Kroma

Kroma aims to develop a universal ZK Rollup based on the Optimism Bedrock architecture. Currently, Kroma operates as an Optimistic Rollup with ZK fault proofs, utilizing a zkEVM based on Scroll. The goal of Kroma is to eventually transition to a ZK Rollup once the generation of ZK proofs becomes more cost-efficient and faster.

How to swap legacy USDC to upgradable USDC

This is a guide on swapping legacy USDC to upgradable USDC with the ratio of 1:1 for the users who bridged USDC tokens before November 23rd, 2023.
To swap your legacy USDC to the new upgradable USDC, please follow the guide below.

Approve legacy USDC tokens

1. 1.Visit the legacy USDC smart contract on Kromascan or Kroma Blockscout.
2. 2.Click 'Contract' tab and then click 'Write as Proxy' button.
3. 3.Connect your wallet by clicking 'Connect to Web3' on Kromascan or 'Connect Wallet' on Blockscout.
4. ​
5. Kromascan - Connect to Web3
6. 
   
7. Kroma Blockscout - Connect wallet
8. 4.Expand the approve function and input 0x89ebAD587e64b2684B1b2E24e451337DceE72F9e for the spender address and 115792089237316195423570985008687907853269984665640564039457584007913129639935 for the amount.
9. ​
10. Kromascan - input sender address and amount
11. ​
12. Kroma Blockscout - input sender address and amount
13. 5.Click 'Write' button to approve the usage of your legacy USDC token for the swap contract.
14. ​
15. Kromascan - Write the approve transaction
16. ​
17. Kroma Blockscout - Write the approve transaction

Swap legacy USDC tokens to upgradable USDC tokens

1. 1.Visit the USDC swap contract on Kromascan or Kroma Blockscout.
2. 2.Click 'Contract' tab and then click 'Write as Proxy' button.
3. 3.Connect your wallet by clicking 'Connect to Web3' on Kromascan or 'Connect Wallet' on Blockscout.
4. ​
5. Kromascan - Connect to Web3
6. ​
7. Kroma Blockscout - Connect wallet
8. 4.Expand the swap function and click 'Write' button to execute the swap. This will swap all of your legacy USDC tokens to the new upgradable USDC tokens.
9. ​
10. Kromascan - Write the swap transaction
11. ​
12. Kroma Blockscout - Write the swap transaction