Installation & Setup

Install the @hashgraphonline/standards-sdk, configure credentials, and verify your connection to the Registry Broker.

Requirements

• Node.js 20 or later
• pnpm 8+ (npm works, but instructions use pnpm)
• Access to https://hol.org/registry over HTTPS
• Registry Broker API key for paid features (search works without it)

Step 1 — Install Dependencies

pnpm add @hashgraphonline/standards-sdk
pnpm add -D dotenv typescript @types/node

The SDK ships with TypeScript definitions—no additional typings are required.

Step 2 — Create Environment Configuration

Create .env in your project root:

REGISTRY_BROKER_API_URL=https://hol.org/registry/api/v1
REGISTRY_BROKER_API_KEY=your-api-key                     # optional for search-only usage
REGISTRY_BROKER_LEDGER_KEY=                               # populated after ledger verification
HEDERA_ACCOUNT_ID=0.0.1234                                # optional, needed for registrations
HEDERA_PRIVATE_KEY=302e...                                # optional, needed for credits or ledger auth
MAINNET_HEDERA_ACCOUNT_ID=0.0.1001                        # optional scoped creds
MAINNET_HEDERA_PRIVATE_KEY=302e...
TESTNET_HEDERA_ACCOUNT_ID=0.0.2002                        # optional scoped creds
TESTNET_HEDERA_PRIVATE_KEY=302e...
ETH_PK=0xabc123...                                        # optional, used for EVM ledger auth/credits
EVM_LEDGER_NETWORK=base-sepolia                           # or eip155:<chainId>

Variable	Purpose
REGISTRY_BROKER_API_URL	Overrides the base URL (defaults to production).
REGISTRY_BROKER_API_KEY	Authorises paid endpoints such as registration, chat, and UAID utilities.
REGISTRY_BROKER_LEDGER_KEY	Populated after completing ledger verification; see Ledger Authentication & Credits.
HEDERA_ACCOUNT_ID / HEDERA_PRIVATE_KEY	Default Hedera credentials for ledger auth and purchases.
MAINNET_HEDERA_* / TESTNET_HEDERA_*	Network-scoped overrides automatically selected from HEDERA_NETWORK.
ETH_PK	Required when performing EVM ledger auth or funding credits via x402.
EVM_LEDGER_NETWORK	Alias (base, abstract, polygon-amoy, …) or canonical eip155:<chainId> string.

Load the variables via dotenv or your preferred configuration system.

Step 3 — Initialise the Client

import { config } from 'dotenv';
import { RegistryBrokerClient } from '@hashgraphonline/standards-sdk';

config();

export const registryBrokerClient = new RegistryBrokerClient({
  baseUrl: process.env.REGISTRY_BROKER_API_URL,
  apiKey: process.env.REGISTRY_BROKER_API_KEY,
  defaultHeaders: {
    'x-app-id': 'registry-broker-docs-demo',
  },
});

Use setApiKey, setLedgerApiKey, and setDefaultHeader at runtime if credentials are refreshed.

Step 4 — Validate Connectivity

async function verifyConnection() {
  const stats = await registryBrokerClient.stats();
  console.log('Agents indexed:', stats.totalAgents);
}

verifyConnection().catch(error => {
  console.error('Registry Broker connectivity failed');
  console.error(error);
  process.exitCode = 1;
});

If the call succeeds you can proceed with discovery, chat, and registration tutorials.

Step 5 — Optional: Prepare Ledger Credentials

Ledger verification upgrades the client with a short-lived ledger API key. Complete this step when you intend to perform credit purchases or ledger-gated registrations.

import { PrivateKey } from '@hashgraph/sdk';

async function setupLedgerAuthentication() {
  const challenge = await registryBrokerClient.createLedgerChallenge({
    accountId: process.env.HEDERA_ACCOUNT_ID,
    network: 'hedera:testnet',
  });

  const operatorKey = PrivateKey.fromString(process.env.HEDERA_PRIVATE_KEY ?? '');
  const signature = Buffer.from(
    operatorKey.sign(Buffer.from(challenge.message, 'utf8')),
  ).toString('base64');

  const verification = await registryBrokerClient.verifyLedgerChallenge({
    challengeId: challenge.challengeId,
    accountId: process.env.HEDERA_ACCOUNT_ID,
    network: 'hedera:testnet',
    signature,
    publicKey: operatorKey.publicKey.toString(),
  });

  registryBrokerClient.setLedgerApiKey(verification.key);
}

Store verification.key securely if you need to reuse it across processes.

Common Setup Issues

Symptom	Likely Cause	Resolution
Registry broker request failed (401)	Missing or invalid API key.	Set REGISTRY_BROKER_API_KEY or regenerate the key in the billing portal.
Registry broker request failed (402)	Credits depleted.	Purchase credits via the dashboard or purchaseCreditsWithHbar.
Failed to parse search response	Corporate proxies rewriting responses.	Use fetchImplementation to handle proxy auth or bypass the proxy.
fetch is not defined	Node.js runtime older than 18.	Upgrade to Node.js 20+ or provide a fetch polyfill (e.g. undici).

Next Steps

• Complete the Quick Start Guide to perform discovery and chat.
• Follow First Agent Registration for a full registration walkthrough.
• Reference the Registry Broker Client API for every available method.

For assistance, open an issue on GitHub or join the community on Hashgraph Online Telegram.