Limiting access to source code

I've setup an online shop and have developed few files only, now what is the best way to limit access of my client's staff from messing the source code? in past they have caused me trouble by playing around with files. How can I avoid it?


Does nopCommerce have a feature to limit this?

Thanks.

This isn't a problem where the solution is found inside Nop.
How / why do they have access to the source. If necessary consider these people on the "outside" and use whatever means you would normally use to secure your server against unauthorized changes. (e.g. restricted file permissions etc )