Illustrator cannot recognize svg code without <svg> and </svg> How to do

If every code is one file you could use a decent text editor and add the codes in batch mode with Find/Change and its RegEx or GREP function of the editor…

I'm on Windows and would perhaps use Notepad++ for this task.

Don't know what's the appropriate tool on a Mac.

( If you are fancy you could even use a tool like Calibre. )

Advanced:

If you know some ExtendScript you could do it with Illustrator:

Open text files, adding text, saving to new name and closing files.

Regards,
Uwe Laubender

( ACP )

What keeps you from adding the tags to the code?

SVG is just plain XML. Every text editor would fit your needs.

Regards,
Uwe Laubender

( ACP )