@rarcifa/cronos-evm-client/README.md

A Node.js client library for interacting with the Cronos EVM, facilitating operations on both CRC20 and CRC721 tokens.

# Cronos EVM Client

The Cronos EVM Client is a TypeScript/JavaScript library designed to facilitate easy and efficient interactions with the Cronos Ethereum Virtual Machine (EVM). This client library provides methods to interact with CRC20 and CRC721 tokens, allowing developers to fetch balances, token metadata, and perform other contract interactions seamlessly.

![npm](https://img.shields.io/npm/v/@rarcifa/cronos-evm-client)

## Features

- Simple and intuitive API for interacting with the Cronos blockchain.
- Supports both CRC20 and CRC721 token standards.
- Configurable client instances tailored to your specific blockchain endpoint and security needs.

## Installation

To install the package, run the following command in your project directory:

```bash
npm install @rarcifa/cronos-evm-client
```

## Usage

Here’s how you can use the Cronos EVM Client in your project:

### Configuring the Client

```ts
import { createClient } from 'cronos-evm-client';

const client = createClient({
  endpoint: 'CRONOS_RPC_ENDPOINT',
  apiKey: 'OPPTIONAL_API_KEY', // optional
});
```

### Fetching CRC20 Token Balance

```ts
const fetchCrc20Balance = async (accountAddress, contractAddress) => {
  try {
    const balance = await client.crc20.getBalanceOf(
      accountAddress,
      contractAddress
    );
    console.log('CRC20 Token Balance:', balance);
  } catch (error) {
    console.error('Error fetching CRC20 balance:', error);
  }
};
```

### Interacting with CRC721 Tokens

```ts
const fetchCrc721Owner = async (contractAddress) => {
  try {
    const owner = await client.crc721.getOwnerOf(contractAddress);
    console.log('CRC721 Owner Address:', owner);
  } catch (error) {
    console.error('Error fetching CRC721 owner:', error);
  }
};
```

## Using the Cronoscan API

You can use the `cronoscan API` method to interact with the Cronos blockchain and fetch transaction data.

### Configuring the Client for Cronoscan

```ts
const client = createClient({
  endpoint: 'https://api.cronoscan.com',
  apiKey: 'API_KEY',
});
```

### Fetching Unique Transactions

```ts
const fetchUniqueTransactions = async (address, startBlock, endBlock) => {
  try {
    const transactions = await client.transactions.getUniqueTransactions(
      address,
      startBlock,
      endBlock
    );
    console.log('Transactions:', transactions);
  } catch (error) {
    console.error('Error fetching transactions:', error);
  }
};
```

### Fetching Block by Timestamp

```ts
const fetchBlockByTimestamp = async (timestamp) => {
  try {
    const blockNumber = await client.transactions.getBlockByTimestamp(
      timestamp
    );
    console.log('Block number:', blockNumber);
  } catch (error) {
    console.error('Error fetching block by timestamp:', error);
  }
};
```

### Counting Unique Transactions (UAW)

```ts
const countUniqueTx = async (
  contractAddresses,
  startBlock,
  endBlock,
  chunkSize = 5000
) => {
  try {
    const uniqueWallets = await client.transactions.countUniqueTransactions(
      contractAddresses,
      startBlock,
      endBlock,
      chunkSize
    );
    console.log('Unique wallets:', uniqueWallets.length);
  } catch (error) {
    console.error('Error counting unique transactions:', error);
  }
};
```

## API

### CRC20 Methods

- `getBalance(accountAddress)`: Fetches the balance of the main token for an account.
- `getBalanceOf(accountAddress, contractAddress)`: Fetches the balance of a specified CRC20 token for an account.
- `getName(contractAddress)`: Fetches the name of the CRC20 token.
- `getSymbol(contractAddress)`: Fetches the symbol of the CRC20 token.
- `getTotalSupply(contractAddress)`: Fetches the total supply of the CRC20 token.

### CRC721 Methods

- `getBalanceOf(accountAddress, contractAddress)`: Fetches the balance of specified CRC721 tokens for an account.
- `getOwnerOf(contractAddress)`: Fetches the owner address of a specific CRC721 token.
- `getTokenUri(contractAddress)`: Fetches the URI pointing to the metadata of the CRC721 token.

### Transactions Methods

- `getUniqueTransactions(address, startBlock, endBlock)`: Fetches unique transactions for a given address between specified blocks.
- `getBlockByTimestamp(timestamp)`: Fetches the block number closest to a given timestamp.
- `countUniqueTransactions(contractAddresses, startBlock, endBlock, chunkSize)`: Counts unique transactions for a list of contract addresses within a specified block range.

## Contributing

Contributions are welcome! If you'd like to contribute, please fork the repository and use a feature branch. Pull requests are warmly welcome.

## Licensing

The code in this project is licensed under MIT license.

## Contact

If you have any questions or comments about the library, please feel free to open an issue or a pull request on our GitHub repository.