Crypto Name Service (CNS) is built on Ethereum and is effectively a bundle of Solidity smart contracts. Their source code is hosted in the dot-crypto repository and maintained by the Unstoppable Domains team. This page lists the smart contracts from that repository and gives a brief description of each along with links to the source code and deployment addresses. For high-level details about how CNS works, see Architecture overview.
This page is divided into sections, grouping contracts by the following categories:
This section lists all the smart contracts that users can directly interact with.
Registry is the central smart contract, which stores all CNS domains. Implementing the ERC-721 non-fungible token standard,
Registry defines domain ownership rules. It stores owner and
Resolver addresses. For more details, see Architecture overview - Registry.
Source code: contracts/Registry.sol
Resolver is the smart contract that stores domain records and provides methods for domain resolution. For more details, see Architecture overview - Resolver.
Source code: contracts/Resolver.sol
ProxyReader provides an interface that allows users to fetch information about domains from both
Resolver smart contracts in one call. For more details, see Architecture overview - ProxyReader.
Source code: contracts/ProxyReader.sol
SignatureController allows any account to submit management transactions on behalf of a token owner if an owner provides a signature for that call.
Source code: contracts/controllers/SignatureController.sol
DomainZoneController allows owners of a domain zone to mint subdomains. These subdomains can be managed only by the domain zone owners. For more details, see Architecture Overview - Alternative Ownership Models.
Source code: contracts/controllers/DomainZoneController.sol
FreeRegistrar is a contract that can be used for allowing any user to freely mint a domain belonging to a subdomain zone.
Source code: contracts/controllers/FreeRegistrar.sol
WhitelistedMinter defines an interface for minting second-level domains. This smart contract is primarily used by the Unstoppable Domains team, but its interface also supports delegating minting process to other parties via Meta Transactions. All calls to
WhitelistedMinter are proxied to the
Registry via the MintingController smart contract.
Source code: contracts/util/WhitelistedMinter.sol
TwitterValidationOperator is used when initiating Chainlink verification requests to link domain records with Twitter usernames.
Source code: contracts/operators/TwitterValidationOperator.sol
The Unstoppable Domains team reserves the right to mint second-level domains and edit some
Registry settings, such as token URI prefix. To avoid giving anyone absolute admin rights,
Registry utilizes controllers that implement a limited set of admin actions.
The deployed version of the
Registry smart contract only allows
MintingController to mint second-level domains. This smart contract is used by WhitelistedMinter as a proxy.
Source code: contracts/controllers/MintingController.sol
URIPrefixController enables the Unstoppable Domains team to edit the token URI prefix.
Source code: contracts/controllers/URIPrefixController.sol
The following interfaces can be used as guidelines for the minimal implementation of custom smart contract versions. Also, Solidity developers can rely on them for making calls to the official CNS smart contracts.
IRegistry interface declares all the
Registry events and methods (both read and write).
Source code: contracts/IRegistry.sol
IRegistryReader interface declares only read-only
Source code: contracts/IRegistryReader.sol
IResolver interface declares the minimal set of
Resolver methods for configuring domain records.
Source code: contracts/IResolver.sol
IResolverReader interface declares the set of methods for reading
Source code: contracts/IResolverReader.sol
IDataReader interface declares the methods that are unique to the
ProxyReader smart contract, which returns combined data from the
Source code: contracts/IDataReader.sol
IMintingController interface declares a set of methods for minting, which both
Source code: contracts/controllers/IMintingController.sol
ISignatureController interface declares the functions that are implemented by
SignatureController to enable Meta transactions for the
Registry smart contract.
Source code: contracts/controllers/ISignatureController.sol
IURIPrefixController interface declares the functions that are implemented by
Source code: contracts/controllers/IURIPrefixController.sol
ERC677Receiver interface declares an ERC-677 method for receiving smart contracts.
Source code: contracts/util/ERC677Receiver.sol
Utility contracts are generally used to share common functionality between other smart contracts. This list also includes some contracts that are used internally by the Unstoppable Domains team.
BulkWhitelistedRole is an extension of Open Zeppelin's
WhitelistedRole that adds bulk operations for adding and removing whitelisted accounts.
Source code: contracts/util/BulkWhitelistedRole.sol
ControllerRole smart contract defines an Open Zeppelin Role, which is used by
Registry to designate controllers.
Source code: contracts/util/ControllerRole.sol
MultiSend smart contract is used internally by the Unstoppable Domains team to fund worker accounts.
Source code: contracts/util/MultiSend.sol
SignatureUtil is a helper smart contract. Its implementation is used to extend smart contracts that require Meta Transactions.
Source code: contracts/util/SignatureUtil.sol
The Truffle migrations smart contract.
Source code: contracts/Migrations.sol
There are several smart contracts that are used for testing purposes without being deployed to public networks or imported by other smart contracts.
LinkTokenMock smart contract is used for testing TwitterValidationOperator.
Source code: contracts/test-helpers/LinkTokenMock.sol
RelayTest is used for testing relaying functionality for Meta Transactions.
Source code: contracts/test-helpers/RelayTest.sol
Simple smart contract is used for testing ERC-721 receiver validation checks.
Source code: contracts/test-helpers/Simple.sol