Arc name registry

ArcNS documentation

One name — @you, you.arc or you.circle — that resolves to an address with a record per chain. Register it once; it's yours forever. Try the resolver, then jump into the docs.

Read the resolver API

Resolve a name · demo

Resolved · @circle · reserved genesis · held by the ArcNS treasury

owner0x3dDF29e9…AcF3A17

ARCcoin 2152525650no record

ETH · BTC · SOLno record

Try it out

Live read

Real answers from Arc testnet, captured against the live API. Browsers on the ArcNS sites read https://api.arcns.io free; agents pay $0.001 a call over x402; the SDK reads chain state directly. Registration is a signed transaction — see the API reference.

Read-only. No wallet and no key for browsers on the ArcNS sites; $0.001 per answer for agents. Registering a name needs a wallet, or registration-as-a-service — see the API reference.

cURL·GET /health

curl -s https://api.arcns.io/health

RESPONSE · 200 (free)

{  "ok": true,  "service": "api",  "version": "0.1.0"}

No RPC call — pure liveness, free for everyone. See the API reference for every route and the payment flow.

ArcNS is live today on app.arcns.io. Names run on Arc testnet (chain id 5042002) while we prepare the mainnet launch — nothing on testnet has monetary value; see Trust & transparency for exactly what that means for you.

Start here

Use your name

Identity & trust

Build & integrate

What ArcNS is

A wallet address is 42 unreadable characters, and one wrong character sends funds nowhere. ArcNS replaces it with a name you can read and share: register @you once and people pay it instead of copying an address, explorers show you as @you instead of raw hex, and one name carries an address record for every chain you use — Arc, Ethereum, Bitcoin, Solana. It's permanent — no renewals, no expiry — and it carries text records you own, so a wallet can finally prove who it belongs to. Start with Why get a name, then register yours.

Three shapes, three namespaces. @alice is a handle; alice.arc and alice.circle are domain-shaped names with subnames. They are three independent registries that can belong to three different people, and every answer names its namespace and the registry it was read from — a mixed shape like @alice.arc is refused, never guessed. See how they fit together.

Why ArcNS

Built to be namespace-safe, not just fast

Four things that are true on Arc testnet today, verified against the deployed contracts.

Three namespaces, one rule

@handle, .arc and .circle are three independent namespaces with three different registries — never merged, never guessed between.

Never guessed, never mixed

Every result names its namespace and registry address. A mixed shape like @alice.arc is refused, not resolved; two registries that disagree are shown side by side.

Permanent registrations

No annual renewal, no expiry, no lapse to a stranger because a payment was missed — a name is registered once, in USDC, and held forever.

Open source, MIT

The .arc / .circle registry, resolver profiles and reverse registrar reuse ENS contracts verbatim; the SDK, API, MCP server and app are all in one repository.

Start hereRegister your nameSearch a name, register it once (two transactions, a minute apart), point it at your addresses, prove you control them, and set it as your primary — the whole thing takes a few minutes on app.arcns.io.Get started

Status

Testnet only. Everything here targets Arc testnet (chain id 5042002, RPC https://rpc.testnet.arc.io, explorer testnet.arcscan.app). Nothing on testnet has monetary value and the deployment may be reset. Mainnet is a separate, gated milestone.
Contracts. Deployed on 2026-09-07 at block 60889698; every address is on the Contracts page, generated from the deployment file in the repository.
App. app.arcns.io is live: search, register, records, verification, primary names, recovery, locks, gifting and the marketplace — see What you can do.
API. https://api.arcns.io holds no keys and no database. Reads are free for browsers on the ArcNS sites and for API-key holders; agents pay $0.001 per call over x402. Registration-as-a-service (POST /raas/register) is live for agents.
SDK. @arcns/resolve is 0.2.0-testnet.1 in the repository's sdk/ directory. It is not on the npm registry yet (checked 2026-09-14): build it from source until the first testnet release lands.
MCP. mcp.arcns.io is live for AI agents — read tools need no auth, write tools return unsigned calls for your own wallet.

Source and licence

The whole project is open source under the MIT licence: fortiblox/fortiblox-arcns. The .arc / .circle registry, resolver profiles, reverse registrar and universal resolver reuse ENS contracts verbatim, so ENS-aware wallets and libraries resolve ArcNS names with the registry address swapped.

Questions

Questions: [email protected].