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ENS on L1 and L2 chains

The Ethereum Name Service (ENS) is a decentralized naming protocol built on Ethereum, mapping human-readable names like enscribe.eth to Ethereum addresses, IPFS content hashes, and smart contracts.

Originally deployed on Ethereum’s Layer 1 (L1), ENS now extends onto Layer 2 (L2) solutions such as Linea and Base, providing faster, lower-cost name registration and resolution.

This documentation provides comprehensive technical details on ENS deployment across L1 and selected L2 chains (Linea and Base), highlighting key differences, contract implementations, and underlying architecture.

ENS on Ethereum L1 (Mainnet and Testnets)​

ENS on Ethereum Mainnet is the canonical deployment, managing global identities under the .eth top-level domain (TLD), such as vitalik.eth. ENS also supports Ethereum testnets such as Sepolia and Holesky, enabling development and experimentation without Mainnet costs.

ENS on Ethereum L1 employs a modular set of contracts:

  • ENS Registry: The central contract storing mappings from ENS names to owners, resolvers, and TTL values. All ENS resolution and ownership checks depend on this registry.
  • BaseRegistrar: Manages registration, renewal, and NFT tokenization (ERC-721) of .eth second-level domains, enabling names like myname.eth to be securely transferred and managed.
  • ETHController: Implements a commitment-based registration mechanism to prevent front-running. It validates registration eligibility, calculates fees, and handles .eth domain registrations.
  • PublicResolver: Stores and resolves name records, including addresses, content hashes, and text metadata. It acts as the standard resolver for most ENS names.
  • ReverseRegistrar: Enables reverse resolution, allowing Ethereum addresses to resolve back to their primary ENS name (alice.eth rather than an address).
  • NameWrapper: Wraps ENS names into ERC-1155 tokens, providing advanced functionality such as granular subname permissions (fuses) and permanent management restrictions.

These contracts form the robust and secure foundation of ENS on Ethereum L1, providing an extensible and highly interoperable identity system.

ENS on Linea​

Linea is a zero-knowledge EVM (zk-EVM) Layer 2 developed by ConsenSys, fully compatible with Ethereum L1, designed to deliver high throughput and lower transaction costs.

On Linea, ENS domains are registered under the second-level domain .linea.eth (e.g., alice.linea.eth). While the contract structure on Linea closely mirrors L1 (Registry, BaseRegistrar, ETHController, ReverseRegistrar, PublicResolver, NameWrapper), domain registration has a distinctive mechanism involving identity verification: Proof of Humanity (PoH).

Proof of Humanity (PoH) ensures .linea.eth domains are registered to unique human identities, mitigating domain squatting risks. Users must pass a PoH verification step to register and control names on Linea.

Additionally, Linea integrates CCIP Read (EIP-3668) for off-chain data resolution. If a name’s data isn’t fully stored on-chain, the resolver delegates the query off-chain, significantly reducing gas costs while maintaining secure, verifiable resolution.

Linea’s ENS thus provides a secure, scalable naming system tightly integrated with Ethereum’s ecosystem, especially valuable for existing Ethereum users seeking cost-effective identity management on L2.

ENS on Base​

Base, built by Coinbase using Optimism’s OP Stack, is a Layer 2 focused on mainstream adoption through faster transactions, lower fees, and simplified experiences. ENS integration on Base provides identity names under the .base.eth domain (e.g., dapp.base.eth).

System Architecture and Components on Base​

ENS on Base is architecturally simplified compared to L1. It does not deploy the NameWrapper or fuses mechanism; all ENS names on Base are thus unwrapped and simplified, facilitating ease of use and lower transaction costs.

The system architecture for ENS on Base is divided into three main functional areas:

L1 Resolver (Cross-chain Resolution)​

An L1 resolver deployed on Ethereum Mainnet enables cross-chain resolution of .base.eth names. When a name is requested from Ethereum L1 and the resolver does not have direct access to the requested data, it triggers an ENSIP-10 compliant CCIP Read (OffchainLookup) response. This instructs clients to retrieve the resolution data from Base’s off-chain gateway.

On-chain ENS-like Registry and Registrar on Base​

Base deploys an optimized set of ENS-like contracts directly on L2:

  • Registry.sol: A simplified version of ENS’s Registry, managing .base.eth subdomain records in a streamlined mapping structure.
  • BaseRegistrar.sol: Derived from ENS’s BaseRegistrarImplementation, it issues ERC-721 tokens for subdomain ownership, managing transfers and expiry.
  • RegistrarController.sol: Permissioned contract managing domain registrations, interfacing with oracles for price calculations and validations.
  • ReverseRegistrar.sol: Enables reverse resolution (address to .base.eth name), allowing addresses to map back to their primary ENS identity on Base.
  • L2Resolver.sol: Functions as the public resolver on Base, storing standard ENS resolution data (address, contenthash, text records, etc.) for .base.eth names.

Off-chain Gateway (CCIP Gateway)​

An off-chain CCIP Gateway service (DID service) handles off-chain resolution requests, compliant with ENSIP-10 (EIP-3668). This gateway efficiently serves resolution data to Ethereum L1 clients querying Base names, minimizing on-chain costs and ensuring rapid cross-chain lookups.

Base ENS provides a frictionless yet powerful identity solution, specifically optimized for the Base environment, suitable for onboarding mainstream users with minimal technical friction.

Enscribe Integration for ENS on L1 and L2​

Enscribe integrates seamlessly with ENS across Ethereum Mainnet (L1), and L2 networks like Linea and Base:

Ethereum L1: Full integration allowing comprehensive name management including registration, forward and reverse resolution and advanced name wrapping capabilities.

Linea: Supports .linea.eth registrations, seamlessly handling Proof of Humanity verification, CCIP Read integration for efficient off-chain resolutions and full forward/reverse resolution capabilities.

Base: Supports streamlined name registrations under .base.eth, interacting directly with Base’s simplified ENS architecture for quick and low-cost naming, forward resolution and cross-chain resolution via L1 resolver and off-chain gateways.

Enscribe abstracts the complexities of these architectures, providing users and developers with an intuitive and uniform interface to leverage ENS capabilities across Ethereum and L2 environments.