yes, it works on your local computer by saving to files and reading them.
it is possible to make sending files over internet, but i do not see a sense in it.
slave script can work on accounts accessed by investor (read-only) passwords and such accounts can be accessed over internet by any trader.

in fact, i have also another solution - scripts for sending and trading signals by email. i even have a program to read those signal and execute them on GAINCapital broker. i can also build custom programs to trade signals on other brokers, if they provide API trading.