Token airdrops are one of the most effective strategies for distributing tokens, building community engagement, and bootstrapping network effects. TRON's low transaction costs and high throughput make it an ideal blockchain for large-scale airdrop campaigns. In this comprehensive guide, we'll build a production-ready TRC-20 token airdrop system from scratch.
Whether you're launching a new project, rewarding loyal users, or conducting a marketing campaign, this guide covers everything from smart contract development to backend implementation and security best practices.
Why Build an Airdrop System on TRON?
Before diving into implementation, let's understand why TRON is particularly well-suited for airdrop campaigns compared to other blockchains.
Cost Advantages
TRON's fee structure makes large-scale token distribution economically viable:
- Near-zero transaction fees - TRC-20 transfers cost fractions of a cent with sufficient Energy
- Energy rental markets - Rent Energy at competitive rates for batch operations
- No gas price volatility - Predictable costs unlike Ethereum's fluctuating gas fees
- Free daily bandwidth - 1,500 free bandwidth points per account daily
A typical airdrop to 10,000 addresses on Ethereum might cost $5,000-$50,000 in gas fees. On TRON, the same operation could cost under $100 with proper optimization. For understanding TRON's resource model in depth, see our Advanced Energy and Bandwidth Optimization Guide.
Speed and Scalability
TRON's technical capabilities support high-volume distributions:
- 2,000 TPS capacity - Process thousands of transfers per second
- 3-second block time - Fast transaction confirmations
- No mempool congestion - Consistent processing times
- Reliable infrastructure - 99.9%+ network uptime
System Architecture Overview
A production airdrop system consists of multiple interconnected components working together to ensure secure, efficient, and verifiable token distribution.
Core Components
┌─────────────────────────────────────────────────────────────┐
│ AIRDROP SYSTEM ARCHITECTURE │
├─────────────────────────────────────────────────────────────┤
│ │
│ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │
│ │ Frontend │───▶│ Backend │───▶│ Database │ │
│ │ (React) │ │ (Node.js) │ │ (PostgreSQL) │ │
│ └──────────────┘ └──────────────┘ └──────────────┘ │
│ │ │ │
│ │ │ │
│ ▼ ▼ │
│ ┌──────────────┐ ┌──────────────┐ │
│ │ TronLink │ │ TronWeb.js │ │
│ │ Wallet │ │ SDK │ │
│ └──────────────┘ └──────────────┘ │
│ │ │ │
│ └───────────────────┘ │
│ │ │
│ ▼ │
│ ┌──────────────────┐ │
│ │ Smart Contracts │ │
│ │ - Airdrop.sol │ │
│ │ - MerkleAirdrop │ │
│ └──────────────────┘ │
│ │ │
│ ▼ │
│ ┌──────────────────┐ │
│ │ TRON Blockchain │ │
│ │ (Mainnet) │ │
│ └──────────────────┘ │
└─────────────────────────────────────────────────────────────┘
No-Code Alternative: CreateTronToken
Before we dive into custom development, it's worth mentioning that not every project needs a custom-built solution. For many use cases, a no-code platform can save significant development time and resources.
Why Consider No-Code?
www.createtrontoken.com offers a comprehensive token creation platform that's ideal for teams without dedicated blockchain developers:
- No coding required - Create fully-featured TRC-20 tokens through an intuitive interface
- Built-in security - Pre-audited smart contracts with industry-standard security
- Advanced features included - Mintable, burnable, pausable tokens with one click
- Instant deployment - Your token live on TRON mainnet in minutes
- Cost-effective - Significantly cheaper than hiring a development team
Creating Your Token for Airdrop
If you need a token to airdrop but don't have one yet, CreateTronToken provides everything you need:
- Visit www.createtrontoken.com
- Configure your token parameters (name, symbol, supply, decimals)
- Select features like mintable supply for future airdrops
- Deploy to TRON mainnet with TronLink
- Receive your token contract address instantly
Once your token is created, you can use the airdrop system we'll build in this guide to distribute it efficiently. For a detailed review, see our CreateTronToken Platform Review.
Smart Contract Development
Now let's build the core smart contracts for our airdrop system. We'll start with a basic implementation and progressively add advanced features.
Basic Airdrop Contract
The simplest airdrop contract allows the owner to distribute tokens to multiple addresses in a single transaction:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
contract BasicAirdrop is Ownable, ReentrancyGuard {
IERC20 public token;
event AirdropExecuted(
address indexed sender,
uint256 recipientCount,
uint256 totalAmount
);
event SingleTransfer(
address indexed recipient,
uint256 amount
);
constructor(address _token) {
require(_token != address(0), "Invalid token address");
token = IERC20(_token);
}
/**
* @notice Execute airdrop to multiple recipients
* @param recipients Array of recipient addresses
* @param amounts Array of amounts for each recipient
*/
function airdrop(
address[] calldata recipients,
uint256[] calldata amounts
) external onlyOwner nonReentrant {
require(
recipients.length == amounts.length,
"Arrays length mismatch"
);
require(recipients.length > 0, "Empty recipients");
require(recipients.length <= 200, "Too many recipients");
uint256 totalAmount = 0;
// Calculate total amount needed
for (uint256 i = 0; i < amounts.length; i++) {
totalAmount += amounts[i];
}
// Verify sufficient allowance
require(
token.allowance(msg.sender, address(this)) >= totalAmount,
"Insufficient allowance"
);
// Execute transfers
for (uint256 i = 0; i < recipients.length; i++) {
require(recipients[i] != address(0), "Invalid recipient");
require(amounts[i] > 0, "Zero amount");
bool success = token.transferFrom(
msg.sender,
recipients[i],
amounts[i]
);
require(success, "Transfer failed");
emit SingleTransfer(recipients[i], amounts[i]);
}
emit AirdropExecuted(msg.sender, recipients.length, totalAmount);
}
/**
* @notice Withdraw any stuck tokens
*/
function withdrawTokens(
address _token,
uint256 amount
) external onlyOwner {
IERC20(_token).transfer(msg.sender, amount);
}
}
Batch Transfer Optimization
For large-scale airdrops, we need to optimize gas usage. Here's an enhanced version with several optimizations:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract OptimizedAirdrop is Ownable {
IERC20 public immutable token;
// Use bitmap to track claimed addresses (gas efficient)
mapping(uint256 => uint256) private claimedBitmap;
// Batch execution tracking
uint256 public currentBatch;
uint256 public totalDistributed;
event BatchCompleted(
uint256 indexed batchId,
uint256 recipientCount,
uint256 totalAmount
);
constructor(address _token) {
token = IERC20(_token);
}
/**
* @notice Optimized airdrop with uniform amounts
* @dev Use this when all recipients get the same amount
*/
function airdropUniform(
address[] calldata recipients,
uint256 amountPerRecipient
) external onlyOwner {
uint256 len = recipients.length;
require(len > 0 && len <= 500, "Invalid batch size");
uint256 totalRequired = len * amountPerRecipient;
require(
token.balanceOf(address(this)) >= totalRequired,
"Insufficient balance"
);
// Use unchecked for gas savings (safe with length check)
unchecked {
for (uint256 i = 0; i < len; ++i) {
token.transfer(recipients[i], amountPerRecipient);
}
totalDistributed += totalRequired;
currentBatch++;
}
emit BatchCompleted(currentBatch, len, totalRequired);
}
/**
* @notice Airdrop with packed data for calldata optimization
* @param packedData Tightly packed recipient+amount data
*/
function airdropPacked(
bytes calldata packedData
) external onlyOwner {
require(packedData.length % 32 == 0, "Invalid data length");
uint256 entries = packedData.length / 32;
uint256 totalAmount = 0;
for (uint256 i = 0; i < entries; i++) {
// Each entry: 20 bytes address + 12 bytes amount
address recipient;
uint96 amount;
assembly {
let offset := add(packedData.offset, mul(i, 32))
let data := calldataload(offset)
recipient := shr(96, data)
amount := and(data, 0xffffffffffffffffffffffff)
}
token.transfer(recipient, amount);
totalAmount += amount;
}
totalDistributed += totalAmount;
currentBatch++;
emit BatchCompleted(currentBatch, entries, totalAmount);
}
/**
* @notice Deposit tokens for airdrop
*/
function depositTokens(uint256 amount) external onlyOwner {
token.transferFrom(msg.sender, address(this), amount);
}
/**
* @notice Withdraw remaining tokens
*/
function withdrawRemaining() external onlyOwner {
uint256 balance = token.balanceOf(address(this));
if (balance > 0) {
token.transfer(msg.sender, balance);
}
}
}
Merkle Tree Whitelist Implementation
For claim-based airdrops where users claim their own tokens, Merkle trees provide an elegant and gas-efficient solution.
Why Use Merkle Trees?
- Gas efficiency - Store only the root hash on-chain, not the entire list
- Scalability - Support millions of recipients without increasing contract storage
- Verifiability - Users can independently verify their eligibility
- Privacy - Full recipient list doesn't need to be public on-chain
Generating Merkle Proofs
First, let's create a utility to generate the Merkle tree and proofs:
// utils/merkle.js
const { MerkleTree } = require('merkletreejs');
const keccak256 = require('keccak256');
const { ethers } = require('ethers');
class AirdropMerkleTree {
constructor(recipients) {
// recipients: [{ address: string, amount: string }]
this.recipients = recipients;
this.leaves = recipients.map(r =>
this.hashLeaf(r.address, r.amount)
);
this.tree = new MerkleTree(this.leaves, keccak256, {
sortPairs: true
});
}
hashLeaf(address, amount) {
return Buffer.from(
ethers.utils.solidityKeccak256(
['address', 'uint256'],
[address, amount]
).slice(2),
'hex'
);
}
getRoot() {
return '0x' + this.tree.getRoot().toString('hex');
}
getProof(address, amount) {
const leaf = this.hashLeaf(address, amount);
return this.tree.getProof(leaf).map(p =>
'0x' + p.data.toString('hex')
);
}
verify(address, amount, proof) {
const leaf = this.hashLeaf(address, amount);
const root = this.tree.getRoot();
return this.tree.verify(proof, leaf, root);
}
// Export for storage/API
exportTree() {
return {
root: this.getRoot(),
recipients: this.recipients.map(r => ({
...r,
proof: this.getProof(r.address, r.amount)
}))
};
}
}
// Usage example
const recipients = [
{ address: 'TXYZabc123...', amount: '1000000000000000000' },
{ address: 'TXYZdef456...', amount: '2000000000000000000' },
// ... more recipients
];
const merkleTree = new AirdropMerkleTree(recipients);
console.log('Merkle Root:', merkleTree.getRoot());
// Export to JSON for API/database storage
const exported = merkleTree.exportTree();
fs.writeFileSync('airdrop-tree.json', JSON.stringify(exported, null, 2));
module.exports = { AirdropMerkleTree };
Merkle Airdrop Contract
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
contract MerkleAirdrop is Ownable, ReentrancyGuard {
IERC20 public immutable token;
bytes32 public merkleRoot;
// Efficient claim tracking with bitmap
mapping(uint256 => uint256) private claimedBitMap;
// Campaign management
uint256 public campaignEndTime;
uint256 public totalClaimed;
bool public paused;
event Claimed(
address indexed account,
uint256 amount,
uint256 indexed index
);
event MerkleRootUpdated(bytes32 oldRoot, bytes32 newRoot);
event CampaignExtended(uint256 newEndTime);
constructor(
address _token,
bytes32 _merkleRoot,
uint256 _duration
) {
token = IERC20(_token);
merkleRoot = _merkleRoot;
campaignEndTime = block.timestamp + _duration;
}
/**
* @notice Check if an index has been claimed
*/
function isClaimed(uint256 index) public view returns (bool) {
uint256 wordIndex = index / 256;
uint256 bitIndex = index % 256;
uint256 word = claimedBitMap[wordIndex];
uint256 mask = (1 << bitIndex);
return word & mask == mask;
}
/**
* @notice Mark an index as claimed
*/
function _setClaimed(uint256 index) private {
uint256 wordIndex = index / 256;
uint256 bitIndex = index % 256;
claimedBitMap[wordIndex] |= (1 << bitIndex);
}
/**
* @notice Claim airdrop tokens
* @param index Recipient index in the merkle tree
* @param amount Amount of tokens to claim
* @param merkleProof Proof of inclusion
*/
function claim(
uint256 index,
uint256 amount,
bytes32[] calldata merkleProof
) external nonReentrant {
require(!paused, "Campaign paused");
require(block.timestamp < campaignEndTime, "Campaign ended");
require(!isClaimed(index), "Already claimed");
// Verify merkle proof
bytes32 leaf = keccak256(
abi.encodePacked(index, msg.sender, amount)
);
require(
MerkleProof.verify(merkleProof, merkleRoot, leaf),
"Invalid proof"
);
// Mark as claimed and transfer
_setClaimed(index);
totalClaimed += amount;
require(token.transfer(msg.sender, amount), "Transfer failed");
emit Claimed(msg.sender, amount, index);
}
/**
* @notice Batch claim for multiple users (admin function)
*/
function batchClaimFor(
uint256[] calldata indices,
address[] calldata accounts,
uint256[] calldata amounts,
bytes32[][] calldata proofs
) external onlyOwner nonReentrant {
require(
indices.length == accounts.length &&
accounts.length == amounts.length &&
amounts.length == proofs.length,
"Array length mismatch"
);
for (uint256 i = 0; i < indices.length; i++) {
if (isClaimed(indices[i])) continue;
bytes32 leaf = keccak256(
abi.encodePacked(indices[i], accounts[i], amounts[i])
);
if (MerkleProof.verify(proofs[i], merkleRoot, leaf)) {
_setClaimed(indices[i]);
totalClaimed += amounts[i];
token.transfer(accounts[i], amounts[i]);
emit Claimed(accounts[i], amounts[i], indices[i]);
}
}
}
// Admin functions
function updateMerkleRoot(bytes32 _newRoot) external onlyOwner {
bytes32 oldRoot = merkleRoot;
merkleRoot = _newRoot;
emit MerkleRootUpdated(oldRoot, _newRoot);
}
function extendCampaign(uint256 additionalTime) external onlyOwner {
campaignEndTime += additionalTime;
emit CampaignExtended(campaignEndTime);
}
function setPaused(bool _paused) external onlyOwner {
paused = _paused;
}
function withdrawUnclaimed() external onlyOwner {
require(block.timestamp >= campaignEndTime, "Campaign active");
uint256 balance = token.balanceOf(address(this));
if (balance > 0) {
token.transfer(msg.sender, balance);
}
}
}
Backend API Implementation
The backend serves as the bridge between users and the blockchain, providing proof generation, eligibility checking, and transaction management.
API Architecture
// server/index.js
const express = require('express');
const TronWeb = require('tronweb');
const { Pool } = require('pg');
const { AirdropMerkleTree } = require('./utils/merkle');
const rateLimit = require('express-rate-limit');
const app = express();
app.use(express.json());
// Rate limiting
const limiter = rateLimit({
windowMs: 15 * 60 * 1000, // 15 minutes
max: 100 // limit each IP to 100 requests per window
});
app.use('/api/', limiter);
// TronWeb instance
const tronWeb = new TronWeb({
fullHost: 'https://api.trongrid.io',
privateKey: process.env.PRIVATE_KEY
});
// Database connection
const pool = new Pool({
connectionString: process.env.DATABASE_URL
});
// Load merkle tree
let merkleTree;
async function loadMerkleTree() {
const result = await pool.query(
'SELECT address, amount, index FROM airdrop_recipients'
);
merkleTree = new AirdropMerkleTree(result.rows);
console.log('Merkle tree loaded, root:', merkleTree.getRoot());
}
// API Endpoints
/**
* Check eligibility and get claim data
*/
app.get('/api/eligibility/:address', async (req, res) => {
try {
const { address } = req.params;
// Validate TRON address
if (!tronWeb.isAddress(address)) {
return res.status(400).json({
eligible: false,
error: 'Invalid TRON address'
});
}
// Check database
const result = await pool.query(
'SELECT index, amount, claimed FROM airdrop_recipients WHERE address = $1',
[address]
);
if (result.rows.length === 0) {
return res.json({
eligible: false,
message: 'Address not in airdrop list'
});
}
const recipient = result.rows[0];
if (recipient.claimed) {
return res.json({
eligible: false,
claimed: true,
message: 'Already claimed'
});
}
// Generate proof
const proof = merkleTree.getProof(address, recipient.amount);
res.json({
eligible: true,
index: recipient.index,
amount: recipient.amount,
proof: proof,
merkleRoot: merkleTree.getRoot()
});
} catch (error) {
console.error('Eligibility check error:', error);
res.status(500).json({ error: 'Internal server error' });
}
});
/**
* Record successful claim
*/
app.post('/api/claim/confirm', async (req, res) => {
try {
const { address, txHash } = req.body;
// Verify transaction on-chain
const tx = await tronWeb.trx.getTransaction(txHash);
if (!tx || tx.ret[0].contractRet !== 'SUCCESS') {
return res.status(400).json({
error: 'Transaction not confirmed'
});
}
// Update database
await pool.query(
'UPDATE airdrop_recipients SET claimed = true, claim_tx = $1, claimed_at = NOW() WHERE address = $2',
[txHash, address]
);
res.json({ success: true });
} catch (error) {
console.error('Claim confirmation error:', error);
res.status(500).json({ error: 'Internal server error' });
}
});
/**
* Get airdrop statistics
*/
app.get('/api/stats', async (req, res) => {
try {
const stats = await pool.query(`
SELECT
COUNT(*) as total_recipients,
COUNT(*) FILTER (WHERE claimed) as total_claimed,
SUM(amount) as total_tokens,
SUM(amount) FILTER (WHERE claimed) as tokens_claimed
FROM airdrop_recipients
`);
res.json(stats.rows[0]);
} catch (error) {
res.status(500).json({ error: 'Internal server error' });
}
});
// Start server
const PORT = process.env.PORT || 3000;
app.listen(PORT, async () => {
await loadMerkleTree();
console.log(`Airdrop API running on port ${PORT}`);
});
Database Schema Design
-- migrations/001_create_airdrop_tables.sql
CREATE TABLE airdrop_campaigns (
id SERIAL PRIMARY KEY,
name VARCHAR(255) NOT NULL,
token_address VARCHAR(42) NOT NULL,
contract_address VARCHAR(42),
merkle_root VARCHAR(66),
total_amount NUMERIC(78, 0) NOT NULL,
start_time TIMESTAMP NOT NULL,
end_time TIMESTAMP NOT NULL,
created_at TIMESTAMP DEFAULT NOW(),
status VARCHAR(20) DEFAULT 'pending'
);
CREATE TABLE airdrop_recipients (
id SERIAL PRIMARY KEY,
campaign_id INTEGER REFERENCES airdrop_campaigns(id),
index INTEGER NOT NULL,
address VARCHAR(42) NOT NULL,
amount NUMERIC(78, 0) NOT NULL,
claimed BOOLEAN DEFAULT FALSE,
claim_tx VARCHAR(66),
claimed_at TIMESTAMP,
created_at TIMESTAMP DEFAULT NOW(),
UNIQUE(campaign_id, address),
UNIQUE(campaign_id, index)
);
CREATE INDEX idx_recipients_address ON airdrop_recipients(address);
CREATE INDEX idx_recipients_claimed ON airdrop_recipients(claimed);
CREATE TABLE airdrop_transactions (
id SERIAL PRIMARY KEY,
campaign_id INTEGER REFERENCES airdrop_campaigns(id),
tx_hash VARCHAR(66) NOT NULL UNIQUE,
batch_number INTEGER,
recipient_count INTEGER,
total_amount NUMERIC(78, 0),
status VARCHAR(20) DEFAULT 'pending',
gas_used NUMERIC(78, 0),
created_at TIMESTAMP DEFAULT NOW(),
confirmed_at TIMESTAMP
);
Claim Verification Endpoint
// server/routes/verify.js
const express = require('express');
const router = express.Router();
/**
* Verify claim before submission
* Helps users avoid failed transactions
*/
router.post('/verify-claim', async (req, res) => {
const { address, index, amount, proof } = req.body;
try {
// 1. Verify address format
if (!tronWeb.isAddress(address)) {
return res.json({
valid: false,
error: 'Invalid address format'
});
}
// 2. Check on-chain claim status
const contract = await tronWeb.contract().at(
process.env.AIRDROP_CONTRACT
);
const claimed = await contract.isClaimed(index).call();
if (claimed) {
return res.json({
valid: false,
error: 'Already claimed on-chain'
});
}
// 3. Verify merkle proof locally
const isValidProof = merkleTree.verify(address, amount, proof);
if (!isValidProof) {
return res.json({
valid: false,
error: 'Invalid merkle proof'
});
}
// 4. Check campaign status
const campaignEnd = await contract.campaignEndTime().call();
if (Date.now() / 1000 > campaignEnd) {
return res.json({
valid: false,
error: 'Campaign has ended'
});
}
// 5. Estimate energy required
const energyEstimate = await estimateClaimEnergy(
address, index, amount, proof
);
res.json({
valid: true,
energyEstimate,
message: 'Ready to claim'
});
} catch (error) {
console.error('Verification error:', error);
res.status(500).json({
valid: false,
error: 'Verification failed'
});
}
});
module.exports = router;
Gas Optimization Techniques
Efficient gas usage is critical for large-scale airdrops. Here are advanced optimization techniques specific to TRON.
Calldata Optimization
// Packed data format reduces calldata size by ~40%
function packAirdropData(recipients) {
// Each entry: 20 bytes (address) + 12 bytes (amount) = 32 bytes
let packed = '0x';
for (const r of recipients) {
// Remove 'T' prefix and convert to hex
const addressHex = tronWeb.address
.toHex(r.address)
.slice(2)
.padStart(40, '0');
// Amount as 12-byte hex (max ~79 billion tokens with 18 decimals)
const amountHex = BigInt(r.amount)
.toString(16)
.padStart(24, '0');
packed += addressHex + amountHex;
}
return packed;
}
// Decode in contract (see airdropPacked function above)
Batch Size Tuning
// Optimal batch sizes for different scenarios
const BATCH_CONFIGS = {
// Uniform amounts - most efficient
uniform: {
maxRecipients: 500,
energyPerRecipient: 15000,
recommendedEnergy: 7500000
},
// Variable amounts
variable: {
maxRecipients: 200,
energyPerRecipient: 20000,
recommendedEnergy: 4000000
},
// Merkle claims (user-initiated)
merkleClaim: {
maxProofLength: 20,
energyEstimate: 50000
}
};
async function calculateOptimalBatchSize(totalRecipients, availableEnergy) {
const config = BATCH_CONFIGS.uniform;
const maxByEnergy = Math.floor(
availableEnergy / config.energyPerRecipient
);
return Math.min(maxByEnergy, config.maxRecipients, totalRecipients);
}
Energy Rental Strategy
For large airdrops, renting Energy is more cost-effective than burning TRX:
// Energy rental calculation
async function calculateEnergyRental(totalRecipients, amountType = 'uniform') {
const config = BATCH_CONFIGS[amountType];
const totalEnergy = totalRecipients * config.energyPerRecipient;
// Current rental rates (example)
const RENTAL_RATE = 0.00005; // TRX per Energy per day
const RENTAL_DURATION = 3; // days
const rentalCost = totalEnergy * RENTAL_RATE * RENTAL_DURATION;
// Compare with burn cost
const burnCost = totalEnergy * 0.00042; // ~420 sun per Energy
return {
totalEnergy,
rentalCost,
burnCost,
savings: burnCost - rentalCost,
recommendation: rentalCost < burnCost ? 'rent' : 'burn'
};
}
// Example: 10,000 recipients
// Total Energy: 150,000,000
// Rental: ~22,500 TRX for 3 days
// Burn: ~63,000 TRX
// Savings: ~40,500 TRX (64%)
Frontend Integration
A user-friendly claim interface is essential for a successful airdrop campaign.
Claim Interface Components
// components/AirdropClaim.jsx
import { useState, useEffect } from 'react';
import { useTronLink } from '../hooks/useTronLink';
export function AirdropClaim({ contractAddress }) {
const { address, tronWeb, connected } = useTronLink();
const [eligibility, setEligibility] = useState(null);
const [claiming, setClaiming] = useState(false);
const [claimed, setClaimed] = useState(false);
const [error, setError] = useState(null);
useEffect(() => {
if (connected && address) {
checkEligibility();
}
}, [connected, address]);
async function checkEligibility() {
try {
const response = await fetch(
`/api/eligibility/${address}`
);
const data = await response.json();
setEligibility(data);
} catch (err) {
setError('Failed to check eligibility');
}
}
async function handleClaim() {
if (!eligibility?.eligible) return;
setClaiming(true);
setError(null);
try {
const contract = await tronWeb.contract().at(contractAddress);
const tx = await contract.claim(
eligibility.index,
eligibility.amount,
eligibility.proof
).send({
feeLimit: 100000000 // 100 TRX max
});
// Wait for confirmation
await waitForConfirmation(tx);
// Notify backend
await fetch('/api/claim/confirm', {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({
address,
txHash: tx
})
});
setClaimed(true);
} catch (err) {
setError(err.message || 'Claim failed');
} finally {
setClaiming(false);
}
}
if (!connected) {
return (
<div className="claim-card">
<h2>Connect Wallet to Check Eligibility</h2>
<button onClick={connectTronLink}>
Connect TronLink
</button>
</div>
);
}
if (claimed) {
return (
<div className="claim-card success">
<h2>🎉 Tokens Claimed Successfully!</h2>
<p>Your tokens have been sent to your wallet.</p>
</div>
);
}
return (
<div className="claim-card">
<h2>Airdrop Claim</h2>
{eligibility?.eligible ? (
<>
<div className="amount-display">
<span>Your Allocation</span>
<strong>
{formatTokenAmount(eligibility.amount)} TOKENS
</strong>
</div>
<button
onClick={handleClaim}
disabled={claiming}
className="claim-button"
>
{claiming ? 'Claiming...' : 'Claim Tokens'}
</button>
</>
) : (
<p className="not-eligible">
{eligibility?.message || 'Checking eligibility...'}
</p>
)}
{error && <p className="error">{error}</p>}
</div>
);
}
Wallet Connection
// hooks/useTronLink.js
import { useState, useEffect, useCallback } from 'react';
export function useTronLink() {
const [tronWeb, setTronWeb] = useState(null);
const [address, setAddress] = useState(null);
const [connected, setConnected] = useState(false);
useEffect(() => {
checkConnection();
// Listen for account changes
window.addEventListener('message', handleTronLinkMessage);
return () => {
window.removeEventListener('message', handleTronLinkMessage);
};
}, []);
function handleTronLinkMessage(e) {
if (e.data?.message?.action === 'accountsChanged') {
checkConnection();
}
}
async function checkConnection() {
if (window.tronWeb && window.tronWeb.ready) {
setTronWeb(window.tronWeb);
setAddress(window.tronWeb.defaultAddress.base58);
setConnected(true);
} else {
setConnected(false);
}
}
const connect = useCallback(async () => {
if (window.tronLink) {
try {
await window.tronLink.request({
method: 'tron_requestAccounts'
});
checkConnection();
} catch (err) {
console.error('Connection rejected:', err);
}
} else {
window.open('https://www.tronlink.org/', '_blank');
}
}, []);
return { tronWeb, address, connected, connect };
}
Security Audit Checklist
Security is paramount when handling token distributions. Use this checklist before deploying to mainnet.
Smart Contract Security
- Reentrancy Protection - Use ReentrancyGuard on all state-changing functions
- Integer Overflow - Solidity 0.8+ has built-in checks; verify for older versions
- Access Control - Proper onlyOwner modifiers on admin functions
- Input Validation - Validate all inputs (addresses, amounts, array lengths)
- Merkle Root Immutability - Consider if root updates should be allowed post-launch
- Claim Index Uniqueness - Ensure indices can't be reused across different campaigns
- Time-based Conditions - Use block.timestamp carefully; miners have slight control
- Emergency Functions - Include pause mechanism for discovered vulnerabilities
Backend Security
- Rate Limiting - Prevent API abuse and DoS attacks
- Input Sanitization - Validate and sanitize all user inputs
- Private Key Management - Use hardware security modules (HSM) for production
- Database Security - Parameterized queries, encryption at rest
- HTTPS Only - Enforce TLS for all API communications
- Monitoring - Set up alerts for unusual activity patterns
Testing and Deployment
Testnet Deployment
// scripts/deploy-testnet.js
const TronWeb = require('tronweb');
async function deployToTestnet() {
const tronWeb = new TronWeb({
fullHost: 'https://api.shasta.trongrid.io',
privateKey: process.env.TESTNET_PRIVATE_KEY
});
// Deploy token first (or use existing)
const tokenContract = await tronWeb.contract().new({
abi: TokenABI,
bytecode: TokenBytecode,
parameters: ['Test Token', 'TEST', 18, 1000000000]
});
console.log('Token deployed:', tokenContract.address);
// Generate merkle tree for test recipients
const testRecipients = generateTestRecipients(100);
const merkleTree = new AirdropMerkleTree(testRecipients);
// Deploy airdrop contract
const airdropContract = await tronWeb.contract().new({
abi: MerkleAirdropABI,
bytecode: MerkleAirdropBytecode,
parameters: [
tokenContract.address,
merkleTree.getRoot(),
86400 * 30 // 30 days duration
]
});
console.log('Airdrop deployed:', airdropContract.address);
console.log('Merkle root:', merkleTree.getRoot());
// Fund the airdrop contract
const totalAmount = testRecipients.reduce(
(sum, r) => sum + BigInt(r.amount),
0n
);
await tokenContract.transfer(
airdropContract.address,
totalAmount.toString()
).send();
console.log('Contract funded with', totalAmount.toString(), 'tokens');
return { tokenContract, airdropContract, merkleTree };
}
deployToTestnet().catch(console.error);
Mainnet Launch Checklist
- Contract Audit - Professional security audit completed
- Testnet Testing - Comprehensive testing on Shasta/Nile
- Merkle Tree Verification - Double-check all recipient data
- Token Funding - Sufficient tokens deposited in contract
- Energy Preparation - Rent/stake adequate Energy for operations
- Backend Deployment - API servers scaled and monitored
- Frontend Launch - Claim page tested across browsers/devices
- Documentation - User guides and FAQs published
- Support Channels - Community support ready for launch
- Monitoring Setup - Real-time dashboards and alerts configured
Monitoring and Analytics
// monitoring/dashboard.js
async function getAirdropMetrics() {
const [
contractBalance,
totalClaimed,
claimCount,
campaignEnd
] = await Promise.all([
token.balanceOf(airdropContract.address).call(),
airdropContract.totalClaimed().call(),
pool.query('SELECT COUNT(*) FROM airdrop_recipients WHERE claimed'),
airdropContract.campaignEndTime().call()
]);
const totalRecipients = await pool.query(
'SELECT COUNT(*) FROM airdrop_recipients'
);
return {
contractBalance: formatTokens(contractBalance),
totalClaimed: formatTokens(totalClaimed),
claimRate: (claimCount / totalRecipients * 100).toFixed(2) + '%',
remainingTime: formatDuration(campaignEnd - Date.now() / 1000),
status: Date.now() / 1000 < campaignEnd ? 'Active' : 'Ended'
};
}
Conclusion and Resources
Building a production-ready airdrop system on TRON requires careful attention to smart contract security, backend architecture, and user experience. The cost advantages of TRON make it an excellent choice for large-scale token distributions.
Key Takeaways:
- Use Merkle trees for gas-efficient, scalable claim-based airdrops
- Optimize batch sizes and leverage Energy rental for cost savings
- Implement comprehensive security measures at every layer
- For simpler needs, consider no-code solutions like www.createtrontoken.com
- Test thoroughly on testnet before mainnet deployment
Additional Resources:
Ready to create a token for your airdrop? Visit www.createtrontoken.com to launch your TRC-20 token in minutes, or follow this guide to build a custom airdrop system tailored to your project's needs.
