The Ava Name Service (ANS) is a distributed, open, and extensible naming system based on the Avalanche blockchain.
ANS’s job is to map human-readable names like ‘dev.ava’ to machine-readable identifiers such as Avalanche C Chain addresses, other cryptocurrency addresses, content hashes, and metadata. ANS also supports ‘reverse resolution’, making it possible to associate metadata such as canonical names or interface descriptions with Ethereum addresses.
ANS has similar goals to DNS, the Internet’s Domain Name Service, but has significantly different architecture due to the capabilities and constraints provided by the Avalanche blockchain. Like DNS, ANS operates on a system of dot-separated hierarchical names called domains, with the owner of a domain having full control over subdomains.
Top-level domains, like ‘.ava’, are owned by smart contracts called registrars, which specify rules governing the allocation of their subdomains. Anyone may, by following the rules imposed by these registrar contracts, obtain ownership of a domain for their own use. ANS also supports importing in DNS names already owned by the user for use on ANS.
This repo doubles as an npm package with the compiled JSON contracts
import {
BaseRegistrar,
BaseRegistrarImplementation,
BulkRenewal,
ENS,
ENSRegistry,
ENSRegistryWithFallback,
ETHRegistrarController,
FIFSRegistrar,
LinearPremiumPriceOracle,
PriceOracle,
PublicResolver,
Resolver,
ReverseRegistrar,
StablePriceOracle,
TestRegistrar
} from '@ensdomains/ans-contracts'// Registry
import '@ensdomains/ens-contracts/contracts/registry/ENS.sol';
import '@ensdomains/ens-contracts/contracts/registry/ENSRegistry.sol';
import '@ensdomains/ens-contracts/contracts/registry/ENSRegistryWithFallback.sol';
import '@ensdomains/ens-contracts/contracts/registry/ReverseRegistrar.sol';
import '@ensdomains/ens-contracts/contracts/registry/TestRegistrar.sol';
// EthRegistrar
import '@ensdomains/ens-contracts/contracts/ethregistrar/BaseRegistrar.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/BaseRegistrarImplementation.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/BulkRenewal.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/BaseRegistrar.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/ETHRegistrarController.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/LinearPremiumPriceOracle.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/PriceOracle.sol';
import '@ensdomains/ens-contracts/contracts/ethregistrar/StablePriceOracle.sol';
// Resolvers
import '@ensdomains/ens-contracts/contracts/resolvers/PublicResolver.sol';
import '@ensdomains/ens-contracts/contracts/resolvers/Resolver.sol';
If your environment does not have compiler, you can access to the raw hardhat artifacts files at node_modules/@ensdomains/ens-contracts/artifacts/contracts/${modName}/${contractName}.sol/${contractName}.json
The ENS registry is the core contract that lies at the heart of ENS resolution. All ENS lookups start by querying the registry. The registry maintains a list of domains, recording the owner, resolver, and TTL for each, and allows the owner of a domain to make changes to that data. It also includes some generic registrars.
Interface of the ANS Registry.
Implementation of the ANS Registry, the central contract used to look up resolvers and owners for domains.
The new impelmentation of the ANS Registry after the 2020 ENS Registry Migration.
Implementation of a simple first-in-first-served registrar, which issues (sub-)domains to the first account to request them.
Implementation of the reverse registrar responsible for managing reverse resolution via the .addr.reverse special-purpose TLD.
Implementation of the .test registrar facilitates easy testing of ENS on the Ethereum test networks. Currently deployed on Ropsten network, it provides functionality to instantly claim a domain for test purposes, which expires 28 days after it was claimed.
Implements an ANS registrar intended for the .ava TLD.
These contracts were audited by ConsenSys dilligence; the audit report is available here.
BaseRegistrar is the contract that owns the TLD in the ANS registry. This contract implements a minimal set of functionality:
- The owner of the registrar may add and remove controllers.
- Controllers may register new domains and extend the expiry of (renew) existing domains. They can not change the ownership or reduce the expiration time of existing domains.
- Name owners may transfer ownership to another address.
- Name owners may reclaim ownership in the ANS registry if they have lost it.
- Owners of names in the interim registrar may transfer them to the new registrar, during the 1 year transition period. When they do so, their deposit is returned to them in its entirety.
This separation of concerns provides name owners strong guarantees over continued ownership of their existing names, while still permitting innovation and change in the way names are registered and renewed via the controller mechanism.
EthRegistrarController is the first implementation of a registration controller for the new registrar. This contract implements the following functionality:
- The owner of the registrar may set a price oracle contract, which determines the cost of registrations and renewals based on the name and the desired registration or renewal duration.
- The owner of the registrar may withdraw any collected funds to their account.
- Users can register new names using a commit/reveal process and by paying the appropriate registration fee.
- Users can renew a name by paying the appropriate fee. Any user may renew a domain, not just the name's owner.
The commit/reveal process is used to avoid frontrunning, and operates as follows:
- A user commits to a hash, the preimage of which contains the name to be registered and a secret value.
- After a minimum delay period and before the commitment expires, the user calls the register function with the name to register and the secret value from the commitment. If a valid commitment is found and the other preconditions are met, the name is registered.
The minimum delay and expiry for commitments exist to prevent miners or other users from effectively frontrunnig registrations.
SimplePriceOracle is a trivial implementation of the pricing oracle for the EthRegistrarController that always returns a fixed price per domain per year, determined by the contract owner.
StablePriceOracle is a price oracle implementation that allows the contract owner to specify pricing based on the length of a name, and uses a fiat currency oracle to set a fixed price in fiat per name.
Resolver implements a general-purpose ANS resolver that is suitable for most standard ANS use-cases. The public resolver permits updates to ANS records by the owner of the corresponding name.
PublicResolver includes the following profiles that implements different EIPs.
- ABIResolver = EIP 205 - ABI support (
ABI()). - AddrResolver = EIP 137 - Contract address interface. EIP 2304 - Multicoin support (
addr()). - ContentHashResolver = EIP 1577 - Content hash support (
contenthash()). - InterfaceResolver = EIP 165 - Interface Detection (
supportsInterface()). - NameResolver = EIP 181 - Reverse resolution (
name()). - PubkeyResolver = EIP 619 - SECP256k1 public keys (
pubkey()). - TextResolver = EIP 634 - Text records (
text()). - DNSResolver = Experimental support is available for hosting DNS domains on the Ethereum blockchain via ANS. The more detail is on the old ANS doc.
Clone the repository:
git clone https://github.com/Ava-Name-Services/ans-contracts.git
Go inside the repo and checkout branch work-branch:
cd ans-contracts;
git checkout work-branch;
Install the dependencies:
yarn
npx hardhat deploy --network fuji
yarn test --network fuji
yarn pub