# Contract Checker

With this functionality, available on Certhis Business Manager,  you can establish customized rules to filter mints in your collection.

<figure><img src="https://927704232-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fk0hw0tz7tJIJ0YnUFa1K%2Fuploads%2FcVNLv0T9108hqvkV6T3a%2Fimage.png?alt=media&#x26;token=395b8d0d-48bc-4083-a685-84556a2272f8" alt=""><figcaption></figcaption></figure>

Example: \
\- If the transaction initiator is blacklisted on the USDT (TETHER) contract. \
\- Verify whether the transaction initiator owns a specific NFT ...\ <br>

This is the interface of the contract checker

```
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

/**
 * An interface for the Icerthis_check contract.
 * Defines the necessary function for checking the validity between two addresses.
 */
interface Icerthis_check {
    /**
     * Function to check the validity or a specific condition between two addresses.
     * The implementation of this function would typically involve some form of verification logic.
     * @param _address The first address to be checked.
     * @param _address2 The second address to be checked.
     * @return A boolean value indicating the result of the check. True if the check passes, false otherwise.
     */
    function check(address _address, address _address2)
        external
        view
        returns (bool);
}
```