TONAPI

TONAPI (tonapi.io) is a public indexed TON API: on top of raw blockchain data, it adds normalised jetton/NFT semantics, event search, and ready-made transaction grouping into “operations”.

How it differs from Toncenter

Toncenter is raw JSON-RPC over liteservers: you see cells, opcodes, low-level transaction structure. TONAPI is the index layer above: you see “Alice sent Bob 100 USDT, fee 0.02 TON”. For DApp UI and analytics, TONAPI usually saves you a lot of parsing.

Key endpoints

• /v2/accounts/<address>/events — normalised account operations (TON-transfer, jetton-transfer, NFT-transfer, etc.).
• /v2/jettons/<master>/holders — top jetton holders.
• /v2/nfts/<collection>/items — NFT collection with metadata.
• /v2/blockchain/... — raw data, when you need it.

An API key is required (free tier with rate limit), available from the tonapi.io dashboard.

Tiers and limits

Tier	RPS	Price	When
Free	~1 RPS	0	prototypes, personal projects
Pro	10-50 RPS	$19-49/mo	production DApps, analytics
Enterprise	by contract	from $500/mo	exchanges, custodial services

The key is passed in the header Authorization: Bearer <key>. Without a key, limits are stricter and there’s no SLA.

Subscribing to events

TONAPI exposes two real-time channels:

• WebSocket — wss://tonapi.io/v2/websocket for account-event subscriptions. Latency ~1-2 seconds from finality.
• SSE (Server-Sent Events) — https://tonapi.io/v2/sse/accounts/<addr>/transactions for one-way streams, convenient for bot notifications and backend watchers.

Example SSE subscription in Node:

import { EventSource } from 'eventsource';
const es = new EventSource(
  `https://tonapi.io/v2/sse/accounts/${addr}/transactions`,
  { headers: { Authorization: `Bearer ${KEY}` } },
);
es.onmessage = (e) => {
  const tx = JSON.parse(e.data);
  console.log('new tx', tx.hash, 'value', tx.value);
};

This pattern powers production bots like @CryptoBot and wallet notification services.

When TONAPI beats Toncenter

• You need jetton operations in human-readable form (USDT-transfer, not raw cells).
• Working with NFT collections — TONAPI returns metadata, owner, history in one call.
• Operation search — e.g. “all swaps for this address over the last week”.
• Ready-made aggregation — fiat balance, total inflows over a period.

When Toncenter is better:

• You need raw BoC / cell to parse a custom smart contract.
• You need runGetMethod against fresh state (TONAPI indexes with a 1-2 second lag).
• You need to broadcast external messages (sendBoc) — TONAPI is indexing-only, not a broadcast endpoint.