Manifest SHA-256: 0x5ba998094d42391d56a9e56e6d55a11f5b52ad9ef9531b973dcc2d12c3a454b1
Release ID: 0xa22373388f708b7df3e546180c9a28477238281f54a2d072d73f7226d824de78
RPC: https://rpc.mainnet.arc.io
USDC: 0x3600000000000000000000000000000000000000

02 / HTTP API

Read names and collectible media without a wallet library.

OpenAPI covers the recommended public routes below. Response envelopes and CORS/cache headers vary by route; internal verification, issuer-v1, compatibility, manifest, and MCP transport routes are intentionally excluded. The canonical V1 registrar does not implement ERC-721 Metadata or tokenURI. Contour provides application-hosted companion metadata and deterministic image endpoints for registered names.

GET/api/name/{label}

Registry, registrar, resolver, expiry, and availability.

GET/api/reverse/{address}

Forward-confirmed primary name.

GET/api/metadata/{tokenId}

Companion metadata derived from a verified registered-name snapshot.

GET/api/image/{tokenId}

Deterministic 1200 × 630 Contour name identity visual.

GET/api/account?owner={address}

Owned names, credits, proceeds, and listings.

GET/api/market

Live fixed-price listings and market state.

GET/api/registration/readiness

Registration contract, signer, controller, and pause readiness.

GET/api/marketplace/readiness

Marketplace contract, settlement, fee, and pause readiness.

POST/api/registration/preflight

Approval requirement and wallet transaction plan.

POST/api/registration/prepare

Wallet-bound registration permit and calldata.

curl "https://contour-arc.vercel.app/api/name/atlas"

curl "https://contour-arc.vercel.app/api/reverse/0x78de409a6306550882328E2a67160471368387FF"

03 / PUBLIC SDK + WORKSPACE REACT

Install the public ESM SDK.

External consumers install contour-sdk with viem on Node.js >=20.9 <25. @contour/react remains a repository-only workspace package and is not included in the public npm release.

npm install contour-sdk viem

SDK / TYPESCRIPT

import {
  ARC_TESTNET,
  ArcNameClient,
  fetchDeploymentManifest,
} from "contour-sdk";
import { createPublicClient, http } from "viem";

const manifest = await fetchDeploymentManifest(
  "https://contour-arc.vercel.app/deployment-manifest.json",
  {
    expectedManifestSha256: "0x5ba998094d42391d56a9e56e6d55a11f5b52ad9ef9531b973dcc2d12c3a454b1",
    expectedReleaseId: "0xa22373388f708b7df3e546180c9a28477238281f54a2d072d73f7226d824de78",
  },
);

const rpc = createPublicClient({
  chain: ARC_TESTNET,
  transport: http(manifest.chain.rpcUrl),
});

const contour = new ArcNameClient(rpc, manifest);
const record = await contour.name("atlas");
const primary = await contour.reverse("0x78de409a6306550882328E2a67160471368387FF");

REACT / TANSTACK QUERY

"use client";

import { useState, type ReactNode } from "react";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import { ArcNameProvider, useArcName } from "@contour/react";
import type { ArcNameClient } from "contour-sdk";

export function ContourProviders({ client, children }: {
  client: ArcNameClient;
  children: ReactNode;
}) {
  const [queries] = useState(() => new QueryClient());
  return <QueryClientProvider client={queries}>
    <ArcNameProvider client={client}>{children}</ArcNameProvider>
  </QueryClientProvider>;
}

export function NameAddress() {
  const { data, isPending } = useArcName("atlas");
  return <span>{isPending ? "Reading..." : data?.resolvedAddress ?? "Not set"}</span>;
}

04 / MCP

Connect directly over HTTPS.

Add the hosted Streamable HTTP endpoint to any MCP client. No clone, local build, absolute path, or environment variable is required.

{
  "mcpServers": {
    "contour-names": {
      "url": "https://contour-arc.vercel.app/api/mcp"
    },
    "arc-docs": {
      "url": "https://docs.arc.io/mcp"
    }
  }
}

normalize_label

Apply the pinned ENSIP-15 single-label profile.

get_name

Read owner, registrant, resolver, address, and lifecycle from Arc.

reverse_lookup

Read a forward-confirmed primary name.

get_account_names

Read the same verified snapshot used by My Names.

get_market

Read verified live listings and marketplace policy.

prepare_registration_request

Build a wallet-bound request for the live registration API.

prepare_permit_request

Exact schema alias for the /api/registration/prepare request.

prepare_approval

Prepare the backwards-compatible registration-controller USDC approval.

prepare_renewal

Prepare an unsigned renewal plan.

prepare_market_token_approval

Approve one name NFT for the pinned marketplace.

prepare_market_token_approval_revoke

Clear one name NFT's token-specific marketplace approval.

prepare_market_usdc_approval

Approve an exact USDC amount for a marketplace purchase.

prepare_market_listing

Prepare an unsigned fixed-price listing plan.

prepare_market_buy

Prepare an unsigned price- and fee-guarded purchase plan.

prepare_market_cancel

Cancel a listing, including while the market is paused.

prepare_claim_proceeds

Claim seller proceeds, including while the market is paused.

prepare_claim_referral

Claim registration referral credits.

prepare_transfer

Safely transfer one active name NFT.

prepare_market_invalidate

Permissionlessly clear one stale raw listing.

Resource: contour://runtime. The Contour MCP never holds a private key, signs, or broadcasts. Reads and unsigned plans use only the canonical Arc HTTPS RPC. Both hosted registration helper names accept rawLabel, explicit normalization acceptance, account, 1-10 years, and an optional request ID, then return an unexecuted /api/registration/prepare POST template. The hosted endpoint needs no npm package; @contour/mcp is a separate, workspace-only stdio server whose contour://manifest resource andprepare_issuer_request challenge/permit templates are a distinct contract.

05 / CONTRACTS + ABI

Seven source-verified deployments.

01registry0x944d5087a0967b3E982826F3d93a7FAcFD4e19cD02baseRegistrar0x5ecE3F5815813668307BdCe1405B5C765E52683703controller0x3FAD66f9F3Ca165118D5b292Fa6036e273718Bf004publicResolver0x156b7785C1E6368324e7aAcD64aFEe1D3e32514605reverseRegistrar0x83697cFE56D1139437D9eC26A7264D5F1C4188f606universalResolver0x4B33c84CdCa6647D75dE93462292edA665c3580007marketplace0x1Ae0F0F22f84Fb11DE30E25982eDf6F0B56B64fd

06 / ARC + CIRCLE

Use the official upstream SDKs.

Use Arc Docs MCP, Circle App Kit, or Circle's x402 SDK alongside the Contour HTTP and MCP surfaces.

ARC DOCS MCPhttps://docs.arc.io/ai/mcp

Connect to the official hosted Arc documentation MCP at https://docs.arc.io/mcp.

OFFICIAL DOCS CIRCLE APP KIThttps://docs.arc.io/app-kit

Official SDK for bridge, swap, send, and unified-balance workflows on Arc.

OFFICIAL DOCS APP KIT INSTALLhttps://docs.arc.io/app-kit/tutorials/installation

Install @circle-fin/app-kit with the official Viem, Ethers, Solana, or Circle Wallets adapter.

OFFICIAL DOCS CIRCLE x402 SDKhttps://developers.circle.com/gateway/nanopayments/references/sdk

Official @circle-fin/x402-batching buyer and seller SDK reference.

OFFICIAL DOCS

07 / AGENTIC x402 & DIRECT WALLET PERMITS

Machine-to-machine Circle x402 payments & direct permits.

Autonomous AI agents on Arc can acquire names using Circle x402 (HTTP 402 Payment Required) nanopayments or direct EIP-712 registration permits without human wallet intervention.

// --- Flow A: Circle x402 Nanopayment ---
// 1. Agent requests registration with x402 payment method
const challenge = await fetch("https://contour-arc.vercel.app/api/registration/prepare", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    rawLabel: "agent-01",
    normalizationAccepted: true,
    durationYears: 1,
    account: agentAddress,
    paymentMethod: "x402",
    requestId: crypto.randomUUID(),
  }),
});
// 2. Server responds with HTTP 402 + PAYMENT-REQUIRED header (Gateway Domain: 26, USDC)
const requirements = challenge.headers.get("PAYMENT-REQUIRED");

// 3. Agent authorizes payment via @circle-fin/x402-batching
const authorization = await exactPaymentClient.authorizePayment(requirements);

// 4. Agent delivers PAYMENT-SIGNATURE to receive the verified registration transaction
const response = await fetch("https://contour-arc.vercel.app/api/registration/prepare", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "PAYMENT-SIGNATURE": authorization,
  },
  body: JSON.stringify({
    rawLabel: "agent-01",
    normalizationAccepted: true,
    durationYears: 1,
    account: agentAddress,
    requestId: crypto.randomUUID(),
  }),
});
const { registrationTransaction, permit, signature } = await response.json();

Circle Gateway Domain: 26

Canonical Arc Mainnet gateway domain for batched nanopayment settlement.

USDC Asset: 0x3600...0000

Arc native USDC ERC-20 contract for 6-decimal sub-cent micropayments.

ERC-8004 Agent Identity

Bind on-chain agent registration and reputation directly to a verified .contour name.

Contour is an independent application built on Arc Mainnet and is not sponsored or endorsed by Circle. Arc is a trademark of Circle Internet Group, Inc. and/or its affiliates.

Loading…

Read names and collectible media without a wallet library.

import { ARC_TESTNET, ArcNameClient, fetchDeploymentManifest, } from "contour-sdk"; import { createPublicClient, http } from "viem"; const manifest = await fetchDeploymentManifest( "https://contour-arc.vercel.app/deployment-manifest.json", { expectedManifestSha256: "0x5ba998094d42391d56a9e56e6d55a11f5b52ad9ef9531b973dcc2d12c3a454b1", expectedReleaseId: "0xa22373388f708b7df3e546180c9a28477238281f54a2d072d73f7226d824de78", }, ); const rpc = createPublicClient({ chain: ARC_TESTNET, transport: http(manifest.chain.rpcUrl), }); const contour = new ArcNameClient(rpc, manifest); const record = await contour.name("atlas"); const primary = await contour.reverse("0x78de409a6306550882328E2a67160471368387FF");

"use client"; import { useState, type ReactNode } from "react"; import { QueryClient, QueryClientProvider } from "@tanstack/react-query"; import { ArcNameProvider, useArcName } from "@contour/react"; import type { ArcNameClient } from "contour-sdk"; export function ContourProviders({ client, children }: { client: ArcNameClient; children: ReactNode; }) { const [queries] = useState(() => new QueryClient()); return <QueryClientProvider client={queries}> <ArcNameProvider client={client}>{children}</ArcNameProvider> </QueryClientProvider>; } export function NameAddress() { const { data, isPending } = useArcName("atlas"); return <span>{isPending ? "Reading..." : data?.resolvedAddress ?? "Not set"}</span>; }

// --- Flow A: Circle x402 Nanopayment --- // 1. Agent requests registration with x402 payment method const challenge = await fetch("https://contour-arc.vercel.app/api/registration/prepare", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ rawLabel: "agent-01", normalizationAccepted: true, durationYears: 1, account: agentAddress, paymentMethod: "x402", requestId: crypto.randomUUID(), }), }); // 2. Server responds with HTTP 402 + PAYMENT-REQUIRED header (Gateway Domain: 26, USDC) const requirements = challenge.headers.get("PAYMENT-REQUIRED"); // 3. Agent authorizes payment via @circle-fin/x402-batching const authorization = await exactPaymentClient.authorizePayment(requirements); // 4. Agent delivers PAYMENT-SIGNATURE to receive the verified registration transaction const response = await fetch("https://contour-arc.vercel.app/api/registration/prepare", { method: "POST", headers: { "Content-Type": "application/json", "PAYMENT-SIGNATURE": authorization, }, body: JSON.stringify({ rawLabel: "agent-01", normalizationAccepted: true, durationYears: 1, account: agentAddress, requestId: crypto.randomUUID(), }), }); const { registrationTransaction, permit, signature } = await response.json();

Build with directArc reads.

Signed evidence. HTTPS runtime.

Read names and collectible media without a wallet library.

Install the public ESM SDK.

Connect directly over HTTPS.

Seven source-verified deployments.

Use the official upstream SDKs.

Machine-to-machine Circle x402 payments & direct permits.

Build with directArc reads.

Signed evidence. HTTPS runtime.

Read names and collectible media without a wallet library.

Install the public ESM SDK.

Connect directly over HTTPS.

Seven source-verified deployments.

Use the official upstream SDKs.

Machine-to-machine Circle x402 payments & direct permits.

Build with direct
Arc reads.

Build with direct
Arc reads.