program plugin based (plugin base)?

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C#

plugin

hi
I’m writing a program which is based on plugin, generally we have a database which has customer list like name and etc plugin written for this project is supposed to calculate the incoming data (information) , assume that there are 4 individuals which are going to write 4 plugins for this program , for instance one obtains the number of customers and the second plugin calculates the debts and etc The thing is how can I enter the customer list in the interface input in a way that ones who write plugins won’t get involved in database and have the information from the interface input and do their job subsequently

namespace PluginBasdeApp.PluginDefenition{
public interface IPlugin
{
     string Name { get;  }


    List<IAction> Actions { get; }


}
}

namespace PluginBasdeApp.PluginDefenition{
public interface IAction
{
    string Name { get; }

    List<Customer> Run(List<Customer> customers );
}
}