Send Gasless Transaction

Send a gasless jetton transfer via the Tonapi relay, paying fees in jettons instead of TON.

This example demonstrates how to send a gasless jetton transfer. A relay pays the TON gas on behalf of the sender, and the commission is deducted from the sender’s jetton balance.

Gasless transfers use the relayer feature provided by tonapi.io and require a TonapiClient with an API key from tonconsole.com. They are only supported on mainnet and only for WalletV5 (WalletV5R1 and WalletV5Beta).

Example

from ton_core import Address, NetworkGlobalID, to_nano

from tonutils.clients import TonapiClient
from tonutils.contracts import WalletV5R1

# Tonapi API key (required for gasless transfers)
# Get one at https://tonconsole.com/
API_KEY = "YOUR_API_KEY"

# Mnemonic phrase
MNEMONIC = "word1 word2 word3 ..."

# Jetton master contract address
# This jetton is used both for the transfer and for gas payment
# Supported jettons: check https://tonapi.io/v2/gasless/config
JETTON_MASTER_ADDRESS = Address("EQ...")

# Destination address (jetton recipient)
DESTINATION_ADDRESS = Address("UQ...")

# Jetton amount in base units (respects token decimals)
# Example: 1 USDT (6 decimals) -> 1 * 10^6 = 1,000,000
JETTON_AMOUNT_TO_SEND = to_nano(1, decimals=6)


async def main() -> None:
    client = TonapiClient(network=NetworkGlobalID.MAINNET, api_key=API_KEY)
    await client.connect()

    wallet, _, _, _ = WalletV5R1.from_mnemonic(client, MNEMONIC)

    # Step 1: Estimate the gasless transfer
    # Builds a jetton transfer message, validates provider and jetton support,
    # and sends it to the Tonapi gasless estimation endpoint.
    # Parameters mirror JettonTransferBuilder.
    estimate = await wallet.gasless_estimate(
        destination=DESTINATION_ADDRESS,
        jetton_amount=JETTON_AMOUNT_TO_SEND,
        jetton_master_address=JETTON_MASTER_ADDRESS,
    )

    # Step 2: Review the estimation result before sending
    # estimate.commission — relay fee (deducted from the jetton balance)
    # estimate.relay_address — address of the relay paying gas
    # estimate.valid_until — unix timestamp, the transaction expires after this time
    # estimate.messages — messages to sign (built by the relay)
    # estimate.emulation — transaction emulation with trace and risk analysis
    print(f"Commission: {estimate.commission} nanocoins")
    print(f"Relay: {estimate.relay_address}")
    print(f"Valid until: {estimate.valid_until}")

    # Step 3: Sign and send via the gasless relay
    await wallet.gasless_send(estimate)
    print("Gasless transfer sent!")

    await client.close()


if __name__ == "__main__":
    import asyncio

    asyncio.run(main())

Always verify the estimated commission and emulation result before calling gasless_send — once sent, the transaction is irreversible.

The same example also appears in Gasless Transfers among the other wallet operations.