What is a Primary Name in ENS?

Understand the fundamental concepts of ENS primary names, reverse vs. forward resolution, and why they're important for smart contract identity and user experience.

The Two-Way Nature of ENS

ENS (Ethereum Name Service) works in two directions, creating a complete naming system that mirrors how the internet's DNS works:

Forward Resolution

ENS Name → Address

alice.eth → 0x1234...5678

This is the familiar direction - typing a name and getting an address.

Reverse Resolution (Primary Name)

Address → ENS Name

0x1234...5678 → alice.eth

This is the "primary name" - when you see an address, it shows the associated name.

Forward resolution helps you find contracts. Reverse resolution helps you recognize them. Together, they create a complete identity system.

What is a Primary Name?

A primary name is the ENS name that an address (wallet or contract) has chosen as its canonical identity. When applications look up that address, they display the primary name instead of the raw hex address.

Key Characteristics

Ownership Required: Only the address owner can set their primary name One at a Time: Each address can have only one primary name
Reversible: The address resolves back to its primary name Voluntary: Setting a primary name is optional

Visual Example

Without Primary Name:

Contract: 0x742d35cc567890c000c000c07c81c25d7df34793
User sees: 0x742d35...34793 (confusing hex)

With Primary Name:

Contract: 0x742d35cc567890c000c000c07c81c25d7df34793
Primary Name: my-defi-vault.eth
User sees: my-defi-vault.eth (clear identity)

Forward vs. Reverse Resolution Deep Dive

Forward Resolution: Name to Address

How it works:

1. User enters mycontract.eth
2. ENS Registry finds the resolver for mycontract.eth
3. Resolver returns the contract address
4. Application connects to that address

Who can set it:

• Anyone who owns or controls the ENS name
• Multiple names can point to the same address
• No restrictions on the target address

Example use cases:

// Multiple names pointing to same contract
uniswap-v3-router.eth → 0xE592...C374
swap-router.eth → 0xE592...C374
router.uniswap.eth → 0xE592...C374

Reverse Resolution: Address to Name

How it works:

1. Application encounters address 0x1234...5678
2. Queries reverse registrar for 1234...5678.addr.reverse
3. Gets back the primary name (if set)
4. Displays name instead of address

Who can set it:

• Only the address itself (for wallets)
• Only the owner of the address (for contracts)
• Requires proving ownership/control

Technical requirement: The address must be able to call the ENS reverse registrar to claim its reverse node.

Primary Names for Smart Contracts

Contract Compatibility

Not all smart contracts can set primary names. The contract must implement specific interfaces:

Interface	Description	Common Use
Ownable	OpenZeppelin ownership pattern	Most common
ERC173	Standard ownership interface	Alternative standard
ReverseClaimer	Custom ENS reverse claiming	Specialized contracts
ReverseSetter	Direct reverse setting capability	Advanced use cases

How Contract Primary Names Work

Compatible Contracts (Ownable/ERC173):

contract MyContract is Ownable {
    constructor(address owner) Ownable(owner) {
        // Contract can have primary name set by owner
    }
}

Process for setting primary name:

1. Contract owner initiates primary name setup
2. ENS reverse registrar verifies ownership
3. Contract's reverse node is claimed
4. Primary name is set for the contract address

Incompatible Contracts:

contract BasicContract {
    // No ownership interface
    // Cannot set primary name
    // Can still have forward resolution
}

Benefits of Primary Names

For Contract Owners

Brand Recognition:

• Contract appears with your chosen name in wallets
• Professional appearance in block explorers
• Consistent identity across platforms

Trust Building:

• Users can verify contract ownership
• Clear association with your project
• Reduced phishing risks

Developer Experience:

// With primary name
const contractName = await provider.lookupAddress(contractAddress);
console.log(contractName); // "my-defi-vault.eth"

// Without primary name  
const contractName = await provider.lookupAddress(contractAddress);
console.log(contractName); // null

For Users

Improved UX:

• See meaningful names instead of hex addresses
• Easier to verify contract authenticity
• Reduced chance of interacting with wrong contracts

Enhanced Security:

• Clear identification of contract ownership
• Harder for scammers to impersonate contracts
• Visual confirmation of legitimate contracts

Better Bookmarking:

• Remember contracts by name, not address
• Consistent names across different dApps
• Easier sharing and discussion

For dApp Developers

Cleaner Interfaces:

// Display name instead of address
function ContractCard({ address }) {
  const { name } = useENSName(address);
  
  return (
    <div>
      <h3>{name || address}</h3>
      <p>Contract: {address}</p>
    </div>
  );
}

Enhanced Analytics:

• Track contracts by recognizable names
• Better user experience metrics
• Clearer transaction histories

Getting Help

Community Support

• Discord: Real-time community help
• Telegram: Developer discussions
• X: Updates and announcements

Documentation Resources

• Complete Docs: Technical reference
• Blog: Updates and announcements
• Check our FAQ

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Ready to set primary names for your contracts? Visit Enscribe and give your smart contracts the human-readable identity they deserve.

Making blockchain addresses human-readable, one primary name at a time.