---
sidebar_position: 2
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import PrivateKeyNote from '@site/src/components/_private-key-note.mdx';

# Quickstart

## Getting Started

The TronWeb is a JavaScript library for building Web3 projects on TRON. It consists of 4 main parts:
1. TransactionBuilder for building transactions with client side integrity check.
2. Trx for requesting data from nodes or sign transactions etc.
3. Contract for interacting with contracts.
4. others useful Utils like in web3.js or ethers.js.

### Installation

#### Node.js

```bash
npm install tronweb
```

or

```bash
yarn add tronweb
```

#### Browser

Then easiest way to use TronWeb in a browser is to install it as above and copy the dist file to your working folder. For example:

```
cp node_modules/tronweb/dist/TronWeb.js ./js/tronweb.js
```

so that you can call it in your HTML page as

```
<script src="./js/tronweb.js"></script>
```

### Instantiation

Then, in your JavaScript file, define TronWeb:

```js
const TronWeb = require('tronweb');
```

When you instantiate TronWeb you can set

- fullHost

Supposing you are using a server which provides everything, like TronGrid, you can instantiate TronWeb as:

```js
const tronWeb = new TronWeb({
  fullHost: 'https://api.trongrid.io',
  headers: { 'TRON-PRO-API-KEY': 'your api key' },
  privateKey: 'your private key'
});
```

Like infura API Key, you can sign up for [TronGrid](https://www.trongrid.io/) and create your API key on the dashboard to access TRON Network data.

<PrivateKeyNote />

### Querying the Tron network

You can query data of Tron network with tronweb.trx easy as follow:

```js
> tronWeb.trx.getBlockByNumber(12345).then(result => {console.log(result)});
Promise { <pending> }
> {
  blockID: '000000000000303987c7c8ab3f5967c107a619fa47819940597e9938811a1764',
  block_header: {
    raw_data: {
      number: 12345,
      txTrieRoot: '0000000000000000000000000000000000000000000000000000000000000000',
      witness_address: '414b4778beebb48abe0bc1df42e92e0fe64d0c8685',
      parentHash: '0000000000003038c0a3aa1806236bc5b281633728b5fe8a14a51062522e651d',
      timestamp: 1529928585000
    },
    witness_signature: 'cb889103aa9ce691d39df8030b54b50b12b77984684281f3490e0b802cbc364c13af773ede8d9314add0fa4d247165be82fa28721f17493c88761b7039ba1c1100'
  }
}
```

### Creating a transaction

TronWeb provide fully apis to satisfy your transaction building demands. No worry about the transaction would be tampered because we do a client side integrity check behind, before the result hands in your hand. See the example:

```js
const transaction = await tronWeb.transactionBuilder.sendTrx("TVDGpn4hCSzJ5nkHPLetk8KQBtwaTppnkr", 100, "TNPeeaaFB7K9cmo4uQpcU32zGK8G1NYqeL");
>{
    "visible": false,
    "txID": "9f62a65d0616c749643c4e2620b7877efd0f04dd5b2b4cd14004570d39858d7e",
    "raw_data": {
        "contract": [
            {
                "parameter": {
                    "value": {
                        "amount": 100,
                        "owner_address": "418840e6c55b9ada326d211d818c34a994aeced808",
                        "to_address": "41d3136787e667d1e055d2cd5db4b5f6c880563049"
                    },
                    "type_url": "type.googleapis.com/protocol.TransferContract"
                },
                "type": "TransferContract"
            }
        ],
        "ref_block_bytes": "0add",
        "ref_block_hash": "6c2763abadf9ed29",
        "expiration": 1581308685000,
        "timestamp": 1581308626092
    },
    "raw_data_hex": "0a020add22086c2763abadf9ed2940c8d5deea822e5a65080112610a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412300a15418840e6c55b9ada326d211d818c34a994aeced808121541d3136787e667d1e055d2cd5db4b5f6c880563049186470ac89dbea822e"
}
```

### Signing a transaction

TronWeb will automatically use the privateKey you provided when you initializing tronweb. Or you can provide an optional privateKey as a second argument.

```js
const signedTransaction = await tronWeb.trx.sign(transaction, privateKey);
```

### Broadcasting

Broadcasting is as easy as follow:

```js
tronWeb.trx.sendRawTransaction(signedTransaction);
```

### Contracts

First, load a contract:
```js
const abi = [...];       
const instance = await tronWeb.contract(abi,'contractAddress');
```

Call read-only methods:

```js
const result = await contract.function_name(para1,para2,...).call();
```

Call state changing methods:

```js
const result = await contract.function_name(para1,para2,...).send({
  feeLimit:100_000_000,
  callValue:0,
  tokenId:1000036,
  tokenValue:100,
  shouldPollResponse:true
});
```