How to send EIP712, EIP1559 transaction request

[mthinh]

Hi, I'm integrating to Lens.xyz, and need to trigger some EIP712, EIP1559 transaction. They actually have sdk for web but not Flutter yet. I check their sdk's repo and found this.
I wonder how we handle to send EIP712/EIP1559 transaction to wallet app. Sorry but I'm new to these one.

Normally, here's how I send normal transaction

Future<String> requestTransaction({
    required String chainId,
    required EthereumTransaction transaction,
  }) async {
    await switchChain(chainId: chainId);

    await Future.delayed(const Duration(milliseconds: 500));
    _w3mService.launchConnectedWallet();

    final transactionId = await _w3mService.request(
      topic: _w3mService.session?.topic ?? '',
      chainId: chainId,
      request: SessionRequestParams(
        method: 'eth_sendTransaction',
        params: [
          transaction.copyWith(data: transaction.data ?? '').toJson(),
        ],
      ),
    );
    if (transactionId is! String) {
      throw Exception('Failed to send transaction ${transactionId.toString()}');
    }
    return transactionId;
  }

@freezed
class EthereumTransaction with _$EthereumTransaction {
  EthereumTransaction._();

  @JsonSerializable(includeIfNull: false)
  factory EthereumTransaction({
    required String from,
    required String to,
    required String value,
    String? nonce,
    String? gasPrice,
    String? maxFeePerGas,
    String? maxPriorityFeePerGas,
    String? gas,
    String? gasLimit,
    String? data,
  }) = _EthereumTransaction;
}

Here's how there SDK send transaction

import { sendTransaction as sendEip1559Transaction, waitForTransactionReceipt } from 'viem/actions';
import { sendEip712Transaction } from 'viem/zksync';

async function sendTransaction(
  walletClient: WalletClient<Transport, chains.LensChain, Account>,
  request: SponsoredTransactionRequest | SelfFundedTransactionRequest,
): Promise<Hash> {
  invariant(
    walletClient.account.address === request.raw.from,
    `Account mismatch: ${walletClient.account} !== ${request.raw.from}`,
  );

  if (request.__typename === 'SponsoredTransactionRequest') {
    return sendEip712Transaction(walletClient, {
      account: walletClient.account,
      data: request.raw.data,
      gas: BigInt(request.raw.gasLimit),
      maxFeePerGas: BigInt(request.raw.maxFeePerGas),
      maxPriorityFeePerGas: BigInt(request.raw.maxPriorityFeePerGas),
      nonce: request.raw.nonce,
      paymaster: request.raw.customData.paymasterParams?.paymaster,
      paymasterInput: request.raw.customData.paymasterParams?.paymasterInput,
      to: request.raw.to,
      value: BigInt(request.raw.value),
    });
  }

  return sendEip1559Transaction(walletClient, {
    account: walletClient.account,
    data: request.raw.data,
    gas: BigInt(request.raw.gasLimit),
    maxFeePerGas: BigInt(request.raw.maxFeePerGas),
    maxPriorityFeePerGas: BigInt(request.raw.maxPriorityFeePerGas),
    nonce: request.raw.nonce,
    to: request.raw.to,
    type: 'eip1559',
    value: BigInt(request.raw.value),
  });
}

[linear]

APKTN-541 How to send EIP712, EIP1559 transaction request