ENS Resolution

eth.zig supports ENS (Ethereum Name Service) resolution -- converting human-readable names like vitalik.eth to Ethereum addresses and back.

Forward Resolution

Resolve an ENS name to an address:

const eth = @import("eth");

var transport = eth.http_transport.HttpTransport.init(allocator, "https://eth.llamarpc.com");
defer transport.deinit();
var provider = eth.provider.Provider.init(allocator, &transport);

// Resolve vitalik.eth -> 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045
const addr = try eth.ens_resolver.resolve(allocator, &provider, "vitalik.eth");

The resolver performs two on-chain lookups:

1. Queries the ENS registry for the resolver contract address
2. Calls addr(bytes32) on the resolver to get the Ethereum address

Returns null if the name has no resolver or resolves to the zero address.

Reverse Resolution

Resolve an address back to an ENS name:

const eth = @import("eth");

const name = try eth.ens_reverse.reverseResolve(allocator, &provider, address);
defer if (name) |n| allocator.free(n);

// name == "vitalik.eth" (or null if no reverse record)

Namehash

Compute the ENS namehash (used internally for registry lookups):

const eth = @import("eth");

const node = eth.ens_namehash.namehash("vitalik.eth");
// node is a [32]u8 hash used as the ENS registry key

The namehash algorithm recursively hashes each label separated by ., as defined in EIP-137.

Text Records

ENS names can have associated text records (email, URL, avatar, etc.). Use getText to look up a record by key:

const eth = @import("eth");

const avatar = try eth.ens_resolver.getText(allocator, &provider, "vitalik.eth", "avatar");
defer if (avatar) |a| allocator.free(a);

// avatar contains the text record value, or null if not set

Common text record keys: avatar, url, email, description, com.twitter, com.github.

Requirements

ENS resolution requires a connection to an Ethereum mainnet node (or a node with ENS registry deployed). The ENS registry contract is at 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e.