Coming at it from a different angle, what claim do the other owners have on your code? You own all code you write unless you do it under a work-for-hire agreement or have assigned ownership under an agreement like this one: https://www.upcounsel.com/intellectual-property-assignment-a...
Talking to a lawyer will be your best bet though.
Like I mentioned above I have NOT signed any agreement. I'm working on meeting with a lawyer now.