How it works

ANS resolves names using two complementary resolver contracts. Understanding them explains what it means for a name and an address to be linked.

Requirements

ANS was designed to satisfy a few rules:

• A Name is represented as an NFT, so it can be easily traded.
• A Name resolves to at most one Address.
• An Address on any group (shard) resolves to at most one Name.
• The holder of the Name NFT can assign any Address to that name.
• An Address does not need to hold the Name NFT to be resolved.
• An Address must give its own permission for which name resolves to it.

The two resolvers

ForwardNameResolver — a single contract on group 0. It records which Address a Name should resolve to. Only the holder of the Name NFT can set this.

ReverseNameResolver — a contract deployed on every group. It records which Name an Address should resolve to. An address can only set its own reverse entry.

What "linked" means

A Name and an Address are considered linked only when both exist:

1. a ForwardNameResolver entry (Name → Address), and
2. a matching ReverseNameResolver entry (Address → Name).

This two‑sided design means linking never requires passing an NFT around: it takes just one transaction from the name holder and one from the target address.

Example

Say the ForwardNameResolver on group 0 holds:

• "bob" → "address_1"
• "alice" → "address_1"
• "steve" → "address_1"

And the ReverseNameResolver on group 1 holds:

• "address_2" → "alice"
• "address_1" → "alice"
• "address_3" → "alice"

With just two lookups — and no off‑chain processing — we can confirm that "alice" and "address_1" are linked, because the forward and reverse entries agree.