Transact with a contract gaslessly

An API key is required to use RallyTransact's infrastructure to power gasless transactions. Visit to generate both Amoy and Mainnet Polygon API keys.

Contract requirements

  1. Contract is compatible with the RallyMobile SDK

    1. Contracts that are ERC2771 compatible are natively supported by the RallyMobile SDK. Those that are not ERC2771 compatible must be whitelisted by us, view the guide here.

Transact with contracts with the relay method

To gaslessly execute a transaction with a contract, create a GSN transaction object and use the relay() method to send the transaction to our relayer.

final gsnTx = GsnTransactionDetails(
    from: accountAddress,
    value: "0",
    to: contractAddress,
    gas: gas.toString(),
    maxFeePerGas: maxFeePerGas.toString(),
    maxPriorityFeePerGas: maxPriorityFeePerGas.toString(),

await amoy.relay(gsnTx)

// relay arbitrary tx through our gasless relayer. see complete example at

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