Introduction #
During a project’s lifecycle, a team may need to replace its token contract. Because deployed blockchain contracts cannot be modified, the usual approach is token mapping: users exchange the old token for the new token at a configured ratio.
For example, Soca, which became popular in 2022, migrated from a high-tax contract to a zero-tax contract at a 1:1 ratio before listing on a centralized exchange.
1. Create a Mapping Contract #
Select Contract Mapping as the airdrop type.
Then enter the contract address of the token to be airdropped. For example, if token A will be mapped to token B, enter the contract address of token B here, then click next.
On this page, fill in the airdrop settings:
- Mapping token contract: if token A will be mapped to token B, enter the contract address of token A here.
- Exchange ratio: the number of airdrop tokens a user receives for paying 1 mapping token. For example, if token A maps to token B at a ratio of
2, the user can exchange 1 token A for 2 token B. - Start time / end time: the valid period of the mapping contract. Users cannot participate before the start time or after the end time.
After filling in the airdrop information, click next and fill in the project information.
This section is the same as the project information section in the presale guide. It is mainly used to introduce the project on the airdrop detail page. The airdrop token logo and project description are required. After completing the fields, click next to review the final project information.
This page displays all final data. After checking that everything is correct, click Finish to create the airdrop contract.
If either the mapping token or the airdrop token has transfer tax, we strongly recommend adding the airdrop contract to the token’s tax whitelist so its transfer tax is 0. Otherwise, the amount received may differ from the configured amount.
You have now created an airdrop contract. You can go to Token Airdrop -> My Airdrops to view all airdrop contracts you created.
Click View Details to enter the airdrop detail page.
2. Deposit Airdrop Tokens #
The mapping contract you just created does not contain any airdrop tokens yet, so users cannot redeem tokens until the contract is funded.
The contract creator can see the Admin Panel on the airdrop detail page. Click Deposit Airdrop Tokens and enter the amount of tokens to deposit.
Depositing is completed in two steps:
- Approve the token.
- Call the deposit contract.
If all airdrop tokens in the contract are claimed, the airdrop stops. The admin can deposit additional airdrop tokens at any time during the valid period to activate the mapping again.
3. User Token Redemption #
Users first click Approve, then click Redeem. The statistics panel below will show the actual amount received.
