> ## Documentation Index
> Fetch the complete documentation index at: https://toncenter.ness.su/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Networks, V2 vs V3, and quick example

Query TON blockchain data through the REST API. The SDK exposes two API versions via a single client — V2 for direct liteserver access and V3 for indexed data.

<Info>
  API key is optional — without a key, requests are throttled to \~1 RPS. Get a key from the [@toncenter](https://t.me/toncenter) bot.
</Info>

## Quick Example

```python theme={"theme":{"light":"github-light-default","dark":"dark-plus"}}
import asyncio

from toncenter.rest import ToncenterRestClient
from toncenter.types import Network
from toncenter.utils import to_amount


async def main() -> None:
    async with ToncenterRestClient(network=Network.MAINNET) as client:
        # V2 — current account state from liteserver
        info = await client.v2.accounts.get_address_information(
            "EQDtFpEwcFAEcRe5mLVh2N6C0x-_hJEM7W61_JLnSF74p4q2"
        )
        print(f"Balance: {to_amount(int(info.balance))} TON")

        # V3 — indexed jetton wallets
        jettons = await client.v3.jettons.get_jetton_wallets(
            owner_address=["EQDtFpEwcFAEcRe5mLVh2N6C0x-_hJEM7W61_JLnSF74p4q2"]
        )
        for jw in jettons.jetton_wallets or []:
            print(f"Jetton: {jw.jetton} — {jw.balance}")


if __name__ == "__main__":
    asyncio.run(main())
```

## Networks

| Network | Enum value        | Base URL                        |
| ------- | ----------------- | ------------------------------- |
| Mainnet | `Network.MAINNET` | `https://toncenter.com`         |
| Testnet | `Network.TESTNET` | `https://testnet.toncenter.com` |

## V2 or V3

They query the same blockchain but serve different purposes.

|                    | API V2                                           | API V3                                       |
| ------------------ | ------------------------------------------------ | -------------------------------------------- |
| **Backend**        | Direct liteserver queries via tonlib             | Indexed PostgreSQL database                  |
| **Latency**        | Real-time (latest block)                         | Near real-time (indexer delay)               |
| **Best for**       | Current state, sending transactions, get-methods | Historical data, search, filters, pagination |
| **Pagination**     | No (fixed result sets)                           | Yes (limit, offset, sort)                    |
| **Jettons/NFTs**   | Single item via get-method                       | Full query API with filters                  |
| **Traces/Actions** | Not available                                    | Full trace trees and parsed actions          |
| **Metadata**       | Not available                                    | Token metadata, address book, DNS records    |

**Use V2 when** you need the latest account state, want to send a transaction, run a smart contract get-method, or work with blocks and shards.

**Use V3 when** you need historical transactions, Jetton/NFT analytics, address book lookups, action traces, or paginated batch queries.