> ## 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.

# The Registrar

> Managing domain registrations

The Namoshi registrar handles the registration of `.btc` and `.citrea` domains. It is an implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721) non-fungible token standard, and provides functionality for registering and renewing domains.

## Domain Registration

Domains are registered via the `ETHRegistrarController`, which acts as a controller for the `BaseRegistrarImplementation`.

### Registration Process

1. **Commit**: To prevent front-running, users must first submit a commitment hash (e.g., `makeCommitment`).
2. **Wait**: After submitting the commitment, users must wait for at least `minCommitmentAge` (usually 1 minute) before revealing their request.
3. **Register**: Once the wait period is over, users can call `register` with the original parameters to complete the registration.

### Cost

The cost of registration is determined by the length of the name and the duration of registration.

* Shorter names are more expensive to prevent spam.
* Longer names are cheaper.
* Registration fees are paid in cBTC.

### Expiry and Grace Period

Domains are registered for a fixed period. After expiry, there is a grace period (usually 90 days) during which the original owner can renew the name.

## Base Registrar Implementation

The `BaseRegistrarImplementation` is the contract that actually owns the `.btc` and `.citrea` TLDs in the ENS registry. It issues subdomains to users who register via the controller.

It implements standard ERC721 functionality:

* `ownerOf(uint256 tokenId)`: Returns the owner of the specified token ID (label hash).
* `transferFrom(address from, address to, uint256 tokenId)`: Transfers ownership of a name.
* `approve(address to, uint256 tokenId)`: Approves another address to manage a specific name.
* `setApprovalForAll(address operator, bool approved)`: Approves an operator to manage all of the user's names.

## Renewals

Domains can be renewed at any time before expiry (and during the grace period) by calling `renew` on the controller.

```solidity theme={null}
function renew(string calldata name, uint256 duration) external payable;
```

This extends the expiration date of the name.