Frequently Asked Questions

Answers to the most common questions about the Registry Broker and the @hashgraphonline/standards-sdk.

General Questions

What is the Registry Broker?

The Registry Broker is a hosted discovery and relay service that indexes AI agents across multiple protocols and networks. It exposes a unified REST API and a typed TypeScript client (RegistryBrokerClient) for discovery, registration, chat relay, analytics, and billing workflows.

Which features require credits?

Free endpoints: keyword search, vector search, metadata facets, registry listings, adapter catalogues, protocol detection, and public stats. Vector search is rate limited; supply an API key—even for anonymous discovery—to receive a dedicated bucket keyed to your key/account rather than the shared IP bucket.
Credit-gated endpoints: agent updates, chat relay (including history operations), UAID utilities, and metrics snapshots. The broker also offers a limited complimentary allowance for evaluation-oriented base registrations and selected lightweight chat paths, but registrations that publish to additional registries and higher-volume usage require credits. See Free Tier for the public policy overview.

Which protocols are supported?

The broker normalises agents registered via A2A, MCP, ERC-8004 networks (multiple L1/L2 chains), OpenRouter-compatible sources, and Hedera-backed UAIDs. See the API reference for the latest protocol utilities.

Technical Questions

How do I get started quickly?

Follow the Quick Start Guide to install the SDK, load environment variables, run keyword and vector searches, and open a chat session.

How do I register or update an agent?

Use the First Agent Registration tutorial for initial publishing, then Update an Agent Registration for updateAgent workflows and completion polling.

What is a UAID?

UAID (Unique Agent Identifier) is the canonical identifier for registered agents. It follows the pattern uaid:aid:{protocol}:{network}:{agent-id} and is returned by registerAgent, resolveUaid, search results, and registration progress APIs.

See the HCS-14 UAID specification for the normative definition and reserved segments.

How does chat relay work?

1. Create a session: client.chat.createSession({ uaid }).
2. Send messages (optionally streaming): client.chat.sendMessage({ sessionId, message }).
3. Read history: client.chat.getHistory(sessionId).
4. Compact history if needed: client.chat.compactHistory({ sessionId, preserveEntries }).
5. End the session: client.chat.endSession(sessionId).

client.chat.createSession is UAID-based. Use a UAID for all current integrations.

Billing & Credits

How do I add credits?

Purchase credits through the billing portal or call client.purchaseCreditsWithHbar with Hedera credentials. Credits become available instantly once the ledger transaction reaches consensus.

What happens if I run out of credits?

Paid endpoints respond with HTTP 402 (Payment Required). The SDK surfaces this as RegistryBrokerError—inspect error.status === 402 and top up credits manually or configure registrationAutoTopUp / historyAutoTopUp.

Can I move credits between projects?

Contact support via the billing portal or the community channel listed below. Credits do not expire and can be reassigned by the operations team.

Development Questions

Which languages are supported?

The official SDK targets TypeScript/JavaScript. Any language can integrate by calling the REST API directly. Community-maintained SDKs exist for select runtimes—check GitHub discussions for links.

Do I need a Hedera account?

Search and discovery work without Hedera credentials. You need a Hedera account and private key to auto-purchase credits, verify ledger challenges, or run registrations that rely on ledger authentication.

How should I handle errors?

import {
  RegistryBrokerClient,
  RegistryBrokerError,
  RegistryBrokerParseError,
} from '@hashgraphonline/standards-sdk';

const client = new RegistryBrokerClient({
  apiKey: process.env.REGISTRY_BROKER_API_KEY,
});

try {
  await client.search({ q: 'agent' });
} catch (error) {
  if (error instanceof RegistryBrokerError) {
    console.error('HTTP error', error.status, error.body);
  } else if (error instanceof RegistryBrokerParseError) {
    console.error('Payload validation failed', error.cause);
  } else {
    throw error;
  }
}

The client only throws two bespoke error classes; all other failures bubble up as the original exception.

Operations Questions

How do I monitor my agents?

• client.stats() returns global registry aggregates such as total agents and registries (/stats endpoint).
• client.dashboardStats() surfaces account-level adapter and registry totals (/dashboard/stats endpoint).
• client.metricsSummary() provides HTTP/search/registration latency and counts directly from the /metrics endpoint.
• For individual agent status, poll client.getRegistrationProgress(attemptId) or client.waitForRegistrationCompletion(attemptId) during registrations.

How do I update or remove an agent?

Use client.updateAgent(uaid, payload) for updates, then follow progress polling if the response is pending. For removals, open a support ticket with ownership proof; self-service deregistration is currently handled through support.

How do I check registration progress?

Call client.getRegistrationProgress(attemptId) or client.waitForRegistrationCompletion(attemptId) after receiving a pending response. Progress data includes per-network statuses and error messages.

Troubleshooting

My agent is not appearing in search results.

• Verify the registration attempt completed successfully in the dashboard.
• Call client.getRegistrationProgress(attemptId) for detailed status.
• Ensure your query matches the agent metadata (name, capabilities, tags).
• Allow a few minutes for the search index to refresh after completion.

Chat sessions are failing.

• Confirm the agent endpoint is reachable and implements the declared protocol.
• Check account credits (HTTP 402 indicates a shortfall).
• For UAID sessions, confirm client.getUaidConnectionStatus(uaid).connected returns true.

I am hitting rate limits.

• Respect the 429 response with exponential backoff.
• Cache discovery responses when possible.
• Avoid overly aggressive polling; space out registration progress checks.

Do I need an XMTP private key to chat with an XMTP agent?

Not when you chat through the Registry Broker.

• Broker-mediated chat (recommended): users call the broker chat endpoint (/api/v1/chat/message) via RegistryBrokerClient using ledger auth or API keys/credits. The broker relays to XMTP using its own XMTP adapter credentials.
• Direct XMTP chat (without the broker): users must have a wallet/signer (private key or equivalent) to create an XMTP client and encrypt/decrypt messages.

Support & Community

• Documentation & tutorials: this directory.
• Community chat: Hashgraph Online Telegram.
• Issue tracking: GitHub Issues.
• Feature requests and roadmap updates: GitHub Discussions.