Quote from maxchinaski:
hello,
not sure what do mean with changes ?
if you mean rollover, you can define a rollover day offset
relative to expiry.
upgrades are free within same major release 1.xxxx
TWSLink installs various samples that demonstrate usage.
so much source code provided (TradeStation, excel, MetaTrader, perl,c#, vb.net, eSignal, etc.)