I got a module that is used for server side scripts and client side scripts, there are some functions that are only for client side context. What can I add to the code to be able to detect if the module is used in the client side context or server side context

You could possibly check for existence of

window

. It'll exist client side.

You can also use the

N/runtime

module and its

executionContext

property: https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_4296531348.html#runtime.executionContext