sgcQUIC Spare dir die Roundtrips. Natives QUIC.

uses
  sgcQUIC_Client;
var
  vQUIC: TsgcQUICClient;
begin
  vQUIC := TsgcQUICClient.Create(nil);
  vQUIC.Host := 'quic.example.com';
  vQUIC.Port := 4433;
  vQUIC.EnableMultiStream := True;
  vQUIC.OnQUICConnect :=
    procedure(Sender: TObject)
    var
      vStreamId: Int64;
    begin
      vStreamId := vQUIC.OpenStream;
      vQUIC.WriteData(vStreamId, 'ping');
    end;
  vQUIC.OnQUICStreamData :=
    procedure(Sender: TObject; const AStreamId: Int64; const AData: string)
    begin
      Memo1.Lines.Add(Format('stream %d: %s', [AStreamId, AData]));
    end;
  vQUIC.Active := True;
end;

uses
  sgcHTTP3_Server;

procedure TForm1.FormCreate(Sender: TObject);
begin
  FServer := TsgcHTTP3Server.Create(nil);
  FServer.Port := 443;
  FServer.QUICOptions.SSLOptions.CertFile := 'server.crt';
  FServer.QUICOptions.SSLOptions.KeyFile  := 'server.key';

  // One handler for every incoming HTTP/3 request
  FServer.OnH3Request :=
    procedure(const Ctx: TsgcHTTP3Context)
    begin
      if Ctx.Path = '/pets/42' then
        Ctx.RespondJSON(200, '{"name":"Rex"}')
      else
        Ctx.Respond(404, 'Not found');
    end;

  FServer.Active := True;
end;