svanas

const Client: IWeb3 = TWeb3.Create('https://mainnet.infura.io/v3/your-project-id');
web3.eth.call(Client, '0xB8c77482e45F1F44dE1745F52C74426C631bDD52', 'symbol()', [], procedure(tup: TTuple; err: IError)
begin
  if Assigned(err) then
  begin
    TThread.Synchronize(nil, procedure
    begin
      MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)
    end);
    EXIT;

svanas

uses
  // Delphi
  System.Classes,
  System.JSON,
  System.UITypes,
  // FireMonkey
  FMX.Controls,
  FMX.Controls.Presentation,
  FMX.Dialogs,
  FMX.Forms,

svanas

var client: IWeb3 := TWeb3.Create('https://<your-node-name>.discover.quiknode.pro/<your-token>/');
web3.eth.blockNumber(client, procedure(num: BigInteger; err: IError)
begin
  TThread.Synchronize(nil, procedure
  begin
    if Assigned(err) then
      MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)
    else
      MessageDlg(num.ToString, TMsgDlgType.mtInformation, [TMsgDlgBtn.mbOK], 0);
  end);

svanas

web3.eth.write(Client,
  TPrivateKey('b5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7'), // from private key
  '0x1a306890df22c0965b0b1515a8082f8301d3d18e',                                    // to smart contract
  'setNumber(uint256)', [143],
  procedure(rcpt: ITxReceipt; err: IError) begin end);

svanas

web3.eth.write(Client,
  TPrivateKey('b5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7'), // from private key
  '0x1a306890df22c0965b0b1515a8082f8301d3d18e',                                    // to smart contract
  'incrementNumber()', [],
  procedure(rcpt: ITxReceipt; err: IError) begin end);

svanas

web3.eth.call(Client,
  '0x1a306890df22c0965b0b1515a8082f8301d3d18e',
  'getNumber()', [], procedure(qty: BigInteger; err: IError)
begin
  TThread.Synchronize(nil, procedure
  begin
    if Assigned(err) then
      MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)
    else
      ShowMessage(qty.ToString);

svanas

var
  Client: IWeb3;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Client := TWeb3.Create(Sepolia.SetRPC('https://sepolia.infura.io/v3/your-project-id'));
end;

svanas

// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.8.0;

contract ArithValue {
    uint number;
    constructor () {
        number = 100;
    }
    function setNumber(uint value) public {

svanas

  web3.eth.call(TWeb3.Create(
    Sepolia.SetRPC(                                   // Sepolia test net
    'https://sepolia.infura.io/v3/your-project-id')), // RPC access to Sepolia
    '0x643C9Db08aBE4D95e4F2Afc733F78b601b84007A',     // smart contract address
    'myFirstHelloWorld()', [], procedure(tup: TTuple; err: IError)
  begin
    TThread.Synchronize(nil, procedure
    begin
      if Assigned(err) then
        MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)

svanas

// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.8.0;

contract HelloWorld {
    function myFirstHelloWorld() public pure returns (string memory) {
        return 'Hello World!';
    }
}