macOS – How to Create an Executable File for AppleScript

on run
    set cat to value of variable "cat" of front workflow (*I have already defined the variable elsewhere in the workflow*)
    set num to {}
    set myString to ""
    tell application "Contacts"
        repeat with i in cat
            set inGroup to group i
            set phoneProps to value of phones of inGroup's people
            repeat with i in phoneProps
                try
                    set myString to myString & "\n" & first item of i (*gets first number only*)
                on error
                    set myString to myString & "\n" & "blank field" (*covers for empty phone number, otherwise would halt on error*)
                end try
            end repeat
        end repeat
        return myString
    end tell  
end run

After few different attempts and hacks I found good solution to solve my problem. First - implement the script. Then open the Automator.app and create new application. Then combine Get Specified Finder Items action and Run AppleScript. So now open -a my_automator_app /path/to/file will pass /path/to/file/ to my script. And that's cool.

P. S. in the argv will be stored the alias to the file, not the posix file path. To convert it from alias to posix you should use

set aliasPath to item 1 of item 1 of argv
set filePath to (the POSIX path of aliasPath)

Oh and don't forget that you might want to get the quoted form of filePath in case it contains some special characters (like space or ~).

You can get more information about alias/posix paths here