API · /hederatopic-api

Hedera Topic API

healthy 4,043 Subscribers

Read the Hedera Consensus Service (HCS) live from the public Hedera mirror node — no key. HCS is Hedera's signature feature: a decentralized, ordered, timestamped message log that powers audit trails, supply-chain tracking, oracles and tokenization registries — the layer that account- and token-readers miss entirely. Look up any topic for its memo, admin/submit-key control, auto-renew and deleted state; read a topic's most recent messages, decoded from base64 to text, each with its consensus sequence number, timestamp and the account that paid to submit it; or discover the topics that are actively receiving messages right now. The consensus-messaging layer for Hedera wallets, explorers, dApps and auditors. Live from the mirror node; short cache only.

#hedera #hcs #consensus #topic #hbar #onchain #crypto

api.oanor.com/hederatopic-api

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Machine-readable spec so AI agents can integrate this API.

/api/hederatopic-api/openapi.json

/api/hederatopic-api/llms.txt

Discovery: GET /api/index.json lists every API.

Hedera Topic API — live data on the oanor API marketplace

API health

healthy

Uptime: 100.00%; Server probes · 24h
Avg latency: 122 ms; Server probes · 24h
Subscribers: 4,043; active
Total calls: 28; last 7 days

Full status page → · 12 probes/24h

Pricing

Pick a tier — billed monthly, cancel anytime.

Free

6,700 calls / month
3 requests / second
Hard cap (429 above quota, no overage)
6,700 calls/month
3 req/sec
Topic + messages + recent
No credit card

Starter

€8.70 /month

125,500 calls / month
8 requests / second
Hard cap (429 above quota, no overage)
125.5k calls/month
8 req/sec
Decoded consensus messages
Email support

Pro

€31.50 /month

747,000 calls / month
20 requests / second
Hard cap (429 above quota, no overage)
747k calls/month
20 req/sec
Active-topic discovery
Priority support

Business

€91.00 /month

4,705,000 calls / month
50 requests / second
Hard cap (429 above quota, no overage)
4.705M calls/month
50 req/sec
Commercial use
Dedicated SLA

Built by

PremiumApi

Related APIs

Other APIs with overlapping tags.

Hedera Network & Nodes API

Read Hedera's network layer live from the public Hedera Mirror Node — no key. Hedera runs on a permissioned set of council-operated consensus nodes; the Hedera on-chain reader resolves account, token and HBAR-supply state, but it does not surface the node set, the live HBAR/USD exchange rate the network itself uses, or the current network fee schedule. This opens that. List the consensus nodes with their node id, account, operator description (e.g. "Hosted by Google | US"), current and min/max stake in HBAR, rewarded vs not-rewarded stake and whether they decline rewards; read the live HBAR↔USD rate the network pins for fee calculation — current and next period, with a derived USD-per-HBAR price — the protocol's own oracle rate, not a market ticker; and read the current network gas fee schedule per transaction type. Stake is reported in HBAR (1 HBAR = 100,000,000 tinybars). The network / validator / economics layer for Hedera explorers, staking dashboards, wallets and analytics. Distinct from the Hedera on-chain reader (account / token / supply), the HCS topic reader and the HTS token browser. Live from the mirror node; short cache only.

api.oanor.com/hederanetwork-api

Hedera HTS Token & NFT API

Browse the Hedera Token Service (HTS) live from the public Hedera Mirror Node — no key. The Hedera on-chain reader resolves a single token's details by id and the tokens an account holds, but it cannot browse the token universe, list the serials inside an NFT collection, or list who holds a token. This opens that. Discover and filter HTS tokens — fungible vs NFT collection, search by name; list the minted serials inside any NFT collection, each with its current owner account and decoded per-serial metadata (often an IPFS or HCS pointer) and whether it has been burned; and list the holders of any token with their decimal-adjusted balances, largest first. Every token and account is a shard.realm.num id like 0.0.107597. The discovery and NFT layer for Hedera wallets, token explorers, NFT marketplaces and analytics. Distinct from the Hedera on-chain reader (per-token-id details and per-account holdings) and from the Hedera Consensus Service topic reader. Live from the mirror node; short cache only.

api.oanor.com/hederatokens-api

Hedera API

Live on-chain data from the Hedera network (HBAR), the enterprise public ledger built on hashgraph consensus, via the public Hedera Mirror Node. Hedera identifies every account, token and contract by a shard.realm.num id like 0.0.2 — not a hash address — and this API speaks that native form. Resolve an account's whole state: HBAR balance, the node or account it stakes to, whether it declines rewards and its pending reward, its auto-renew and token-association settings, memo and EVM nonce. Get the HTS tokens an account holds, each decimal-adjusted with token id and freeze/KYC status. Read any HTS token's details — name, symbol, decimals, total and max supply, treasury account and whether it's a fungible token or an NFT collection. Get the live HBAR supply, released and total. Live, no key, nothing stored. Distinct from the XRP Ledger, Stellar, TRON, Aptos, Algorand, Tezos, Cardano, Solana and EVM on-chain APIs and from price feeds — this is Hedera account state, staking, HTS-token holdings, token details and HBAR supply. Perfect for wallets, explorers, treasury, HTS-token and analytics apps.

api.oanor.com/hedera-api

Nano Representatives & Consensus API

Nano's Open Representative Voting (ORV) consensus — the representative layer — live from the public Nano RPC, no key, nothing cached. Nano has no miners and no staking rewards: every account delegates its balance as voting weight to a representative, and online representatives vote to confirm transactions, with a quorum threshold securing the network. The base Nano reader covers accounts, blocks and history, but not the representative layer; this opens it. Rank the online representatives by delegated voting weight (in NANO), each with its share of total online stake and whether it clears the 0.1%-of-online-stake principal-representative threshold that earns a vote in consensus. Look up a single representative by address for its weight, stake share, principal status and whether it is currently online and voting. And read the live confirmation quorum — the total online voting stake, the trended and peer stake, the quorum delta and percentage, and the minimum weight a representative needs to count. The consensus-and-voting layer for Nano wallets, representative dashboards, delegators and analytics. Live from rpc.nano.to and peer nodes.

api.oanor.com/nanoreps-api

Frequently asked questions

Quick answers about pricing, quotas, and integration.

How do I get an API key for Hedera Topic API?

Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Hedera Topic API with the x-oanor-key header. No credit card needed for the free tier.

What's the rate limit for Hedera Topic API?

Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.

How much does Hedera Topic API cost?

Hedera Topic API has a free tier with 100 calls / month. Paid plans start at €8.70 / month with higher quotas and faster rate limits.

Can I cancel my subscription anytime?

Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.

Is Hedera Topic API GDPR-compliant?

All requests to Hedera Topic API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.

HCS 3

Meta 1

Pick an endpoint from the list on the left to see its details and try it.

GET /v1/messages

A topic's recent decoded messages

Playground

Parameters

Custom headers

Language: Client:

GET /v1/recent

Topics actively receiving messages right now

Playground

Parameters

Custom headers

Language: Client:

GET /v1/topic

HCS topic metadata (omit id for the demo topic)

Playground

Parameters

Custom headers

Language: Client:

GET /v1/meta

Service metadata & live sample

Playground

Custom headers

Language: Client:

Code snippets

curl https://api.oanor.com/hederatopic-api/SOME_PATH \
  -H "x-oanor-key: oanor_test_..."

const res = await fetch("https://api.oanor.com/hederatopic-api/SOME_PATH", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();

$ch = curl_init("https://api.oanor.com/hederatopic-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);

import requests
r = requests.get(
    "https://api.oanor.com/hederatopic-api/SOME_PATH",
    headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())

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Hedera Topic API

API health

Pricing

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Related APIs

Hedera Network & Nodes API

Hedera HTS Token & NFT API

Hedera API

Nano Representatives & Consensus API

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