Post

Introducing ruby gem 'gasfree_sdk' – Send USDT without TRX or Energy on TRON

Learn how to send USDT TRC-20 on the TRON blockchain without needing TRX or energy using the Ruby gem gasfree_sdk. Discover how to build gasless transactions and simplify your Web3 dApp UX.

If you’re building Web3 applications on TRON, and especially dealing with USDT TRC‑20, you know the hassle: you need TRX to pay for bandwidth and energy, or buy and burn it—even for free transfers! With gasfree_sdk, you can use your own USDT to cover those fees, and your users don’t need to buy or rent TRX at all.


⚡ Why Gasless USDT Transfers?

  • Zero TRX needed – No more buying TRX or estimating resources.
  • Use USDT directly – Fees are deducted from the USDT you’re sending.
  • Simplified UX – Lower friction for onboarding and micro‑transfers.

What’s changed on TRON?

  1. Tron network introduced “Gas‑Free” USDT transfers: Justin Sun announced a feature enabling USDT to cover gas costs directly—no TRX required (cryptotimes.io, coincodex.com, ironwallet.io, the-blockchain.com, coinscan.com, chainwire.org).
  2. Press coverage confirms launch: Multiple outlets like Crypto Times, Crypto News Flash, The Blockchain News, and more noted that “Gas Free” would start in late Feb 2025, letting wallets and dApps send USDT without TRX (cryptotimes.io, binance.com).
  3. Pilot rollouts have begun: Wallets like IronWallet and Tonkeeper Pro now support gasless USDT-TRC20 transactions, confirming user benefits (coincodex.com).

🚀 What gasfree_sdk Lets You Do

  1. Backend signs USDT meta-tx You pay using USDT, and all TRX energy/bandwidth is covered transparently.

  2. Integrated with Gelato Relay The script handles EIP‑712‑style signing and payload preparing for gasless relay.

  3. True “gasless UX” Your users only interact with USDT—they never touch TRX.


🛠️ How It Works

1. Install

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gem install gasfree_sdk
# or in Gemfile:
gem 'gasfree_sdk'

2. Configure

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require 'gasfree_sdk'

GasfreeSdk.configure do |config|
  config.api_key = "your-api-key"
  config.api_secret = "your-api-secret"
  config.api_endpoint = "https://open.gasfree.io/tron/"
end

3. Initialize

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client = GasfreeSdk.client
# Get supported tokens
puts "Supported Tokens:"
tokens = client.tokens
tokens.each do |token|
  puts "  #{token.symbol} (#{token.token_address})"
  puts "    Activation Fee: #{token.activate_fee}"
  puts "    Transfer Fee: #{token.transfer_fee}"
end

# Get service providers
puts "\nService Providers:"
providers = client.providers
providers.each do |provider|
  puts "  #{provider.name} (#{provider.address})"
  puts "    Max Pending Transfers: #{provider.config.max_pending_transfer}"
  puts "    Default Deadline: #{provider.config.default_deadline_duration}s"
end

4. Get your Gasless USDT address

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user_private_key = "your-private-key"
user_address = "your-address"

puts "\nGasFree Account Info:"
account = client.address(user_address)
puts "  GasFree Address: #{account.gas_free_address}"
puts "  Active: #{account.active}"
puts "  Nonce: #{account.nonce}"

5. Prepare Meta-Transaction

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token = tokens.first
provider = providers.first

deadline_int = Time.now.to_i + provider.config.default_deadline_duration
message = {
  token: token.token_address,
  serviceProvider: provider.address,
  user: user_address,
  receiver: "TQ7ew8mijfJoQ2qSAqSXmjUx1KbB96oMqc",
  value: "100000000", # 100 USDT (6 decimals)
  maxFee: "2000000", # Activation fee + transfer fee
  deadline: deadline_int.to_s,
  version: 1,
  nonce: account_nonce
}

6. Sign the message

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sig = TronEIP712Signer.sign_typed_data(user_private_key, message)

7. Send It

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sdk_message = {
  token: message[:token],
  service_provider: message[:serviceProvider],
  user: message[:user],
  receiver: message[:receiver],
  value: message[:value],
  max_fee: message[:maxFee],
  deadline: message[:deadline].to_i,
  version: message[:version],
  nonce: message[:nonce]
}

request = GasfreeSdk::Models::TransferRequest.new(
  sdk_message.merge(sig: sig)
)

5. Verify & Monitor

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response = client.submit_transfer(request)
  puts "  ✅ Transfer submitted successfully!"
  puts "  Transfer ID: #{response.id}"
  puts "  State: #{response.state}"
  puts "  Estimated Fees:"
  puts "    Activation: #{response.estimated_activate_fee}"
  puts "    Transfer: #{response.estimated_transfer_fee}"

  # Monitor transfer status
  puts "\nMonitoring Transfer Status:"
  5.times do
    status = client.transfer_status(response.id)
    puts "  State: #{status.state}"
    puts "  Transaction Hash: #{status.txn_hash}" if status.txn_hash
    break if %w[SUCCEED FAILED].include?(status.state)

    sleep 2
  end

✅ Use Cases

  • Wallets & dApps wanting seamless USDT pickups
  • Micro‑payments where TRX friction kills UX
  • Platforms enabling DAO votes or community payouts

📢 TRON Gasless News Coverage

  • Tron to Enable Gas-Free USDT Transfers Next Week” — Crypto Times & others confirm feature by Justin Sun (mpost.io, binance.com, the-blockchain.com, cryptotimes.io).
  • Tron Introduces ‘Gas-Free’ USDT Transfers” — detailed blog coverage on full removal of TRX gas (coinscan.com).
  • Gasless USDT‑TRC20 Transactions in Tonkeeper Pro Are Now Live” — live support in wallets confirms real rollout (chainwire.org).

📝 Contribute & Feedback

Want to add features or tweak behaviors? PRs welcome in the repo. Ensure you include tests!


💡 Final Thoughts

TRON is now officially gas-free for USDT transactions, and gasfree_sdk empowers Ruby devs to leverage this natively. Send USDT, not TRX—streamlined, low-cost, and easy.


📚 References

This post is licensed under CC BY 4.0 by the author.

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