> ## Documentation Index
> Fetch the complete documentation index at: https://docs.namoshi.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Discounts

> Save on domain registrations

Namoshi offers a flexible discount system that allows users to register domains at reduced costs. This system is modular and supports multiple types of validation logic.

## Discount Validators

Namoshi uses `IDiscountValidator` implementations to check if a user is eligible for a discount. The main validator types are:

### Referral System

The `SecureReferralDiscountValidator` allows users to register domains using a referral code.

* **Discount**: Users get a % off the registration fee.
* **Security**: The referral code is cryptographically verified to ensure authenticity.

### NFT Ownership

The `ERC721DiscountValidator` and `MultipleNFTDiscountValidator` grant discounts to holders of specific NFT collections.

* **Check**: The contract verifies `balanceOf(user) > 0` for the configured NFT contract.
* **Stacking**: With `MultipleNFTDiscountValidator`, holding NFTs from multiple collections can stack discounts (up to a limit).

### Whitelists

The `MerkleWhitelistDiscountValidator` allows for efficient on-chain whitelist verification.

* **Merkle Proof**: Users submit a Merkle proof along with their registration to prove they are in the whitelist.
* **Gas Efficient**: Only the root hash is stored on-chain.

## Applying Discounts

To use a discount, pass the appropriate data to the `registerWithDiscount` function on the controller:

```solidity theme={null}
function registerWithDiscount(
    string memory name,
    address owner,
    uint256 duration,
    address resolver,
    bytes[] memory data,
    bool reverseRecord,
    uint16 fuses,
    uint64 wrapperExpiry,
    bytes memory discountData
) public payable;
```

The `discountData` parameter contains the proof or signature required by the active `DiscountValidator`.