how to load injection lib in mac applications at application start?

I have a dynamic library, I intent to inject in running application & newly launched applications.

I can inject it in running applications with the help of a process running with root user permissions.

Now I am trying that library should get loaded as soon as application is launched. I know one such library开发者_开发技巧 capable of doing this called, application enhancer. I am looking for similar behavior.

Does anyone has an Idea how can this be achieved?

Look at SIMBL agent code. It adds a observer to application launch notification and then injects. You can follow the same approach.