@tetherto/wdk-wallet-tron-gasfree

Note: This package is currently in beta. Please test thoroughly in development environments before using in production.

A simple and secure package to manage BIP-44 wallets for the Tron blockchain with gas-free TRC20 token transfers. This package provides a clean API for creating, managing, and interacting with Tron wallets using BIP-39 seed phrases and Tron-specific derivation paths, with support for gas-free operations via a service provider.

🔍 About WDK

This module is part of the WDK (Wallet Development Kit) project, which empowers developers to build secure, non-custodial wallets with unified blockchain access, stateless architecture, and complete user control.

For detailed documentation about the complete WDK ecosystem, visit docs.wallet.tether.io.

🌟 Features

• Gas-Free Transactions: Support for gas-free transactions using TRC20 tokens
• Tron Derivation Paths: Support for BIP-44 standard derivation paths for Tron
• Multi-Account Management: Create and manage multiple accounts from a single seed phrase
• TRC20 Support: Query native TRX and TRC20 token balances using smart contract interactions
• Message Signing: Sign and verify messages using Tron cryptography

⬇️ Installation

To install the @tetherto/wdk-wallet-tron-gasfree package, follow these instructions:

You can install it using npm:

npm install @tetherto/wdk-wallet-tron-gasfree

🚀 Quick Start

Importing from @tetherto/wdk-wallet-tron-gasfree

Creating a New Gas-Free Wallet

import WalletManagerTronGasfree, { 
  WalletAccountTronGasfree, 
  WalletAccountReadOnlyTronGasfree 
} from '@tetherto/wdk-wallet-tron-gasfree'

// Use a BIP-39 seed phrase (replace with your own secure phrase)
const seedPhrase = 'test only example nut use this real life secret phrase must random'

// Create wallet manager with required configuration
const wallet = new WalletManagerTronGasfree(seedPhrase, {
  // Tron network configuration
  chainId: '728126428', // Tron chain ID
  provider: 'https://api.trongrid.io', // or any other Tron RPC provider
  // Gas-free service configuration
  gasFreeProvider: 'https://gasfree.provider.url', // Gas-free provider's URL
  gasFreeApiKey: 'your-gasfree-api-key', // Gas-free provider's API key
  gasFreeApiSecret: 'your-gasfree-api-secret', // Gas-free provider's API secret
  serviceProvider: 'T...', // Service provider's address
  verifyingContract: 'T...', // Verifying contract's address
  
  // Optional configuration
  transferMaxFee: 10000000n // Maximum fee in sun (optional)
})

// Get a full access account
const account = await wallet.getAccount(0)

// Convert to a read-only account
const readOnlyAccount = await account.toReadOnlyAccount()

Managing Multiple Accounts

import WalletManagerTronGasfree from '@tetherto/wdk-wallet-tron-gasfree'

// Assume wallet is already created
// Get the first account (index 0)
const account = await wallet.getAccount(0)
const address = await account.getAddress()
console.log('Account 0 address:', address)

// Get the second account (index 1)
const account1 = await wallet.getAccount(1)
const address1 = await account1.getAddress()
console.log('Account 1 address:', address1)

// Get account by custom derivation path
// Full path will be m/44'/195'/0'/0/5
const customAccount = await wallet.getAccountByPath("0'/0/5")
const customAddress = await customAccount.getAddress()
console.log('Custom account address:', customAddress)

// Note: All addresses are Tron addresses (T...)
// All accounts inherit the provider configuration from the wallet manager

Checking Balances

Owned Account

For accounts where you have the seed phrase and full access:

import WalletManagerTronGasfree from '@tetherto/wdk-wallet-tron-gasfree'

// Assume wallet and account are already created
// Get native TRX balance (in sun)
const balance = await account.getBalance()
console.log('Native TRX balance:', balance, 'sun') // 1 TRX = 1000000 sun

// Get TRC20 token balance
const tokenContract = 'T...'; // TRC20 contract address
const tokenBalance = await account.getTokenBalance(tokenContract);
console.log('TRC20 token balance:', tokenBalance);

// Note: Provider is required for balance checks
// Make sure wallet was created with a provider configuration

Read-Only Account

For addresses where you don't have the seed phrase:

import { WalletAccountReadOnlyTronGasfree } from '@tetherto/wdk-wallet-tron-gasfree'

// Create a read-only account
const readOnlyAccount = new WalletAccountReadOnlyTronGasfree('T...', { // Tron address
  chainId: '728126428',
  provider: 'https://api.trongrid.io', // Required for balance checks
  gasFreeProvider: 'https://gasfree.provider.url',
  gasFreeApiKey: 'your-gasfree-api-key',
  gasFreeApiSecret: 'your-gasfree-api-secret',
  serviceProvider: 'T...'
})

// Check native TRX balance
const balance = await readOnlyAccount.getBalance()
console.log('Native TRX balance:', balance, 'sun')

// Check TRC20 token balance using contract
const tokenBalance = await readOnlyAccount.getTokenBalance('T...') // TRC20 contract address
console.log('TRC20 token balance:', tokenBalance)

// Note: TRC20 balance checks use the standard balanceOf(address) function
// Make sure the contract address is correct and implements the TRC20 standard

Sending Transactions

⚠️ Important Note: Direct transaction sending using sendTransaction() is not supported in WalletAccountTronGasfree. This is a gas-free implementation that handles transactions through a gas-free provider instead of direct blockchain transactions.

For sending tokens, please use the transfer() method instead.

Token Transfers (Gas-Free)

Transfer TRC20 tokens and estimate fees using WalletAccountTronGasfree. Uses gas-free operations via service provider.

// Transfer TRC20 tokens using gas-free transactions
const transferResult = await account.transfer({
  token: 'T...',      // TRC20 contract address
  recipient: 'T...',  // Recipient's Tron address
  amount: 1000000n     // Amount in TRC20's base units (use BigInt for large numbers)
}, {
  transferMaxFee: 1000000n // Optional: Maximum fee allowed for the transfer
});
console.log('Transfer hash:', transferResult.hash);
console.log('Transfer fee:', transferResult.fee, 'sun');

// Quote token transfer fee
const transferQuote = await account.quoteTransfer({
  token: 'T...',      // TRC20 contract address
  recipient: 'T...',  // Recipient's Tron address
  amount: 1000000n     // Amount in TRC20's base units
})
console.log('Transfer fee estimate:', transferQuote.fee, 'sun') // Includes both transfer and activation fees if needed

// Note: Gas fees are handled by the gas-free service provider
// Ensure proper gas-free service configuration before transfers

Message Signing and Verification

Sign and verify messages using WalletAccountTronGasfree.

// Sign a message
const message = 'Hello, Tron!'
const signature = await account.sign(message)
console.log('Signature:', signature)

// Verify a signature
const isValid = await account.verify(message, signature)
console.log('Signature valid:', isValid)

Fee Management

Retrieve current fee rates using WalletManagerTronGasfree.

// Get current fee rates
const feeRates = await wallet.getFeeRates();
console.log('Normal fee rate:', feeRates.normal, 'sun');
console.log('Fast fee rate:', feeRates.fast, 'sun');

Memory Management

Clear sensitive data from memory using dispose methods in WalletAccountTronGasfree and WalletManagerTronGasfree.

// Dispose wallet accounts to clear private keys from memory
account.dispose()

// Dispose entire wallet manager
wallet.dispose()

📚 API Reference

Table of Contents

| Class | Description | Methods | |-------|-------------|---------| | WalletManagerTronGasfree | Main class for managing Tron wallets with gas-free features. Extends WalletManager from @tetherto/wdk-wallet. | Constructor, Methods | | WalletAccountTronGasfree | Individual Tron wallet account implementation with gas-free features. Extends WalletAccountReadOnlyTronGasfree and implements IWalletAccount from @tetherto/wdk-wallet. | Constructor, Methods, Properties | | WalletAccountReadOnlyTronGasfree | Read-only Tron wallet account with gas-free features. Extends WalletAccountReadOnly from @tetherto/wdk-wallet. | Constructor, Methods |

WalletManagerTronGasfree

The main class for managing Tron wallets with gas-free features.
Extends WalletManager from @tetherto/wdk-wallet.

Constructor

new WalletManagerTronGasfree(seed, config)

Parameters:

• seed (string | Uint8Array): BIP-39 mnemonic seed phrase or seed bytes
• config (object, optional): Configuration object
  • chainId (string): The blockchain's id
  • provider (string | TronWeb): Tron RPC endpoint URL or TronWeb instance (e.g., 'https://api.trongrid.io')
  • gasFreeProvider (string): The gasfree provider's url
  • gasFreeApiKey (string): The gasfree provider's api key
  • gasFreeApiSecret (string): The gasfree provider's api secret
  • serviceProvider (string): The address of the service provider
  • verifyingContract (string): The address of the verifying contract
  • transferMaxFee (number | bigint, optional): Maximum fee amount for transfer operations (in sun)

Example:

const wallet = new WalletManagerTronGasfree(seedPhrase, {
  chainId: '728126428',
  provider: 'https://api.trongrid.io',
  gasFreeProvider: 'https://gasfree.trongrid.io',
  gasFreeApiKey: 'your-api-key',
  gasFreeApiSecret: 'your-api-secret',
  serviceProvider: 'T...', // Service provider address
  verifyingContract: 'T...', // Verifying contract address
  transferMaxFee: '10000000' // Maximum fee in sun
})

Methods

| Method | Description | Returns | |--------|-------------|---------| | getAccount(index) | Returns a wallet account at the specified index | Promise<WalletAccountTronGasfree> | | getAccountByPath(path) | Returns a wallet account at the specified BIP-44 derivation path | Promise<WalletAccountTronGasfree> | | getFeeRates() | Returns current fee rates for transactions | Promise<{normal: bigint, fast: bigint}> | | dispose() | Disposes all wallet accounts, clearing private keys from memory | void |

getAccount(index)

Returns a gas-free Tron wallet account at the specified index using BIP-44 derivation path m/44'/195'.

Parameters:

• index (number, optional): The index of the account to get (default: 0)

Returns: Promise<WalletAccountTronGasfree> - The gas-free Tron wallet account

Example:

const account = await wallet.getAccount(0)
const address = await account.getAddress()
console.log('Gas-free Tron account address:', address)

getAccountByPath(path)

Returns a gas-free Tron wallet account at the specified BIP-44 derivation path.

Parameters:

• path (string): The derivation path (e.g., "0'/0/0", "1'/0/5")

Returns: Promise<WalletAccountTronGasfree> - The gas-free Tron wallet account

Example:

const account = await wallet.getAccountByPath("0'/0/1")
const address = await account.getAddress()
console.log('Custom path gas-free address:', address)

getFeeRates()

Returns current fee rates for Tron transactions (used by service provider for gas-free operations).

Returns: Promise<{normal: bigint, fast: bigint}> - Object containing fee rates in sun

• normal: Standard fee rate for normal confirmation speed
• fast: Higher fee rate for faster confirmation

Example:

const feeRates = await wallet.getFeeRates()
console.log('Normal fee rate:', feeRates.normal, 'sun')
console.log('Fast fee rate:', feeRates.fast, 'sun')

// Note: These fees are typically covered by the service provider in gas-free transactions

dispose()

Disposes all gas-free Tron wallet accounts and clears sensitive data from memory.

Returns: void

Example:

wallet.dispose()
// All gas-free accounts and private keys are now securely wiped from memory

WalletAccountTronGasfree

Represents an individual wallet account with gas-free features. Implements IWalletAccount from @tetherto/wdk-wallet.

Constructor

new WalletAccountTronGasfree(seed, path, config)

Parameters:

• seed (string | Uint8Array): BIP-39 mnemonic seed phrase or seed bytes
• path (string): BIP-44 derivation path (e.g., "0'/0/0")
• config (object, optional): Configuration object
  • chainId (string): The blockchain's id
  • provider (string | TronWeb): Tron RPC endpoint URL or TronWeb instance
  • gasFreeProvider (string): The gasfree provider's url
  • gasFreeApiKey (string): The gasfree provider's api key
  • gasFreeApiSecret (string): The gasfree provider's api secret
  • serviceProvider (string): The address of the service provider
  • verifyingContract (string): The address of the verifying contract
  • transferMaxFee (number | bigint, optional): Maximum fee amount for transfer operations (in sun)

Methods

| Method | Description | Returns | |--------|-------------|---------| | getAddress() | Returns the account's address | Promise<string> | | sign(message) | Signs a message using the account's private key | Promise<string> | | verify(message, signature) | Verifies a message signature | Promise<boolean> | | transfer(options, config?) | Transfers TRC20 tokens to another address | Promise<{hash: string, fee: bigint}> | | quoteTransfer(options) | Estimates the fee for a TRC20 transfer | Promise<{fee: bigint}> | | getBalance() | Returns the native TRX balance (in sun) | Promise<bigint> | | getTokenBalance(tokenAddress) | Returns the balance of a specific TRC20 token | Promise<bigint> | | dispose() | Disposes the wallet account, clearing private keys from memory | void |

getAddress()

Returns the account's Tron address.

Returns: Promise<string> - The Tron address

Example:

const address = await account.getAddress()
console.log('Gas-free Tron address:', address) // TLyqzVGLV1srkB7dToTAEqgDSfPtXRJZYH

sign(message)

Signs a message using the account's private key.

Parameters:

• message (string): Message to sign

Returns: Promise<string> - Signature as hex string

Example:

const signature = await account.sign('Hello Tron Gas-Free!')
console.log('Signature:', signature)

verify(message, signature)

Verifies a message signature using the account's public key.

Parameters:

• message (string): Original message
• signature (string): Signature as hex string

Returns: Promise<boolean> - True if signature is valid

Example:

const isValid = await account.verify('Hello Tron Gas-Free!', signature)
console.log('Signature valid:', isValid)

transfer(options, config?)

Transfers TRC20 tokens to another address using gas-free operations where the service provider covers transaction fees.

Parameters:

• options (object): Transfer options
  • token (string): TRC20 contract address (e.g., 'T...')
  • recipient (string): Recipient Tron address (e.g., 'T...')
  • amount (number | bigint): Amount in TRC20's base units
• config (object, optional): Additional configuration
  • transferMaxFee (number | bigint, optional): Maximum allowed fee for this transfer

Returns: Promise<{hash: string, fee: bigint}> - Object containing hash and fee (typically 0 or covered by service provider)

Example:

const result = await account.transfer({
  token: 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t', // USDT TRC20
  recipient: 'TLyqzVGLV1srkB7dToTAEqgDSfPtXRJZYH',
  amount: 1000000n // 1 USDT (6 decimals)
})
console.log('Gas-free transfer hash:', result.hash)
console.log('Fee (covered by service provider):', result.fee, 'sun')

quoteTransfer(options)

Estimates the fee for a TRC20 token transfer (typically covered by service provider in gas-free operations).

Parameters:

• options (object): Transfer options
  • token (string): TRC20 contract address
  • recipient (string): Recipient Tron address
  • amount (number | bigint): Amount in TRC20's base units

Returns: Promise<{fee: bigint}> - Object containing estimated fee (typically 0 or covered by service provider)

Example:

const quote = await account.quoteTransfer({
  token: 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t', // USDT TRC20
  recipient: 'TLyqzVGLV1srkB7dToTAEqgDSfPtXRJZYH',
  amount: 1000000n // 1 USDT (6 decimals)
})
console.log('Estimated fee (service provider will cover):', quote.fee, 'sun')

getBalance()

Returns the account's native TRX balance in sun.

Returns: Promise<bigint> - Balance in sun

Example:

const balance = await account.getBalance()
console.log('TRX balance:', balance, 'sun')
console.log('Balance in TRX:', Number(balance) / 1e6)

getTokenBalance(tokenAddress)

Returns the balance of a specific TRC20 token.

Parameters:

• tokenAddress (string): The TRC20 token contract address

Returns: Promise<bigint> - Token balance in token's smallest unit

Example:

// Get USDT TRC20 balance (6 decimals)
const usdtBalance = await account.getTokenBalance('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t')
console.log('USDT balance:', Number(usdtBalance) / 1e6)

dispose()

Disposes the wallet account, securely erasing the private key from memory.

Returns: void

Example:

account.dispose()
// Private key is now securely wiped from memory

Properties

| Property | Type | Description | |----------|------|-------------| | index | number | The derivation path's index of this account | | path | string | The full derivation path of this account | | keyPair | object | The account's key pair (⚠️ Contains sensitive data) |

⚠️ Security Note: The keyPair property contains sensitive cryptographic material. Never log, display, or expose the private key.

WalletAccountReadOnlyTronGasfree

Represents a read-only wallet account with gas-free features.

Constructor

new WalletAccountReadOnlyTronGasfree(address, config)

Parameters:

• address (string): The account's Tron address
• config (object, optional): Configuration object
  • chainId (string): The blockchain's id
  • provider (string | TronWeb): Tron RPC endpoint URL or TronWeb instance
  • gasFreeProvider (string): The gasfree provider's url
  • gasFreeApiKey (string): The gasfree provider's api key
  • gasFreeApiSecret (string): The gasfree provider's api secret
  • serviceProvider (string): The address of the service provider

Methods

| Method | Description | Returns | |--------|-------------|---------| | getBalance() | Returns the native TRX balance (in sun) | Promise<bigint> | | getTokenBalance(tokenAddress) | Returns the balance of a specific TRC20 token | Promise<bigint> | | quoteTransfer(options) | Estimates the fee for a TRC20 transfer | Promise<{fee: bigint}> |

getBalance()

Returns the account's native TRX balance in sun.

Returns: Promise<bigint> - Balance in sun

Example:

const balance = await readOnlyAccount.getBalance()
console.log('TRX balance:', balance, 'sun')
console.log('Balance in TRX:', Number(balance) / 1e6)

getTokenBalance(tokenAddress)

Returns the balance of a specific TRC20 token.

Parameters:

• tokenAddress (string): The TRC20 token contract address

Returns: Promise<bigint> - Token balance in token's smallest unit

Example:

// Get USDT TRC20 balance (6 decimals)
const usdtBalance = await readOnlyAccount.getTokenBalance('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t')
console.log('USDT balance:', Number(usdtBalance) / 1e6)

quoteTransfer(options)

Estimates the fee for a TRC20 token transfer (typically covered by service provider in gas-free operations).

Parameters:

• options (object): Transfer options
  • token (string): TRC20 contract address
  • recipient (string): Recipient Tron address
  • amount (number | bigint): Amount in TRC20's base units

Returns: Promise<{fee: bigint}> - Object containing estimated fee (typically 0 or covered by service provider)

Example:

const quote = await readOnlyAccount.quoteTransfer({
  token: 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t', // USDT TRC20
  recipient: 'TLyqzVGLV1srkB7dToTAEqgDSfPtXRJZYH',
  amount: 1000000n // 1 USDT (6 decimals)
})
console.log('Estimated fee (service provider will cover):', quote.fee, 'sun')
console.log('Estimated fee in TRX:', Number(quote.fee) / 1e6)

🌐 Supported Networks

This package works with the Tron blockchain, including:

• Tron Mainnet
• Tron Shasta Testnet

🔒 Security Considerations

• Seed Phrase Security: Always store your seed phrase securely and never share it
• Private Key Management: The package handles private keys internally with memory safety features
• Provider Security: Use trusted RPC endpoints and consider running your own node for production
• Transaction Validation: Always validate transaction details before signing
• Memory Cleanup: Use the dispose() method to clear private keys from memory when done
• Fee Limits: Set transferMaxFee in config to prevent excessive transaction fees
• Gas-Free Provider: Validate gas-free provider configuration and API credentials
• Service Provider: Ensure service provider address is correct and trusted
• Contract Interactions: Verify contract addresses and token decimals before transfers

🛠️ Development

Building

# Install dependencies
npm install

# Build TypeScript definitions
npm run build:types

# Lint code
npm run lint

# Fix linting issues
npm run lint:fix

Testing

# Run tests
npm test

# Run tests with coverage
npm run test:coverage

📜 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

🆘 Support

For support, please open an issue on the GitHub repository.