Unfortunately not possible, at least not securely, and not in a way that users would expect. I really tried.

We could include _a_ fingerprint sensor, and even include a special secure/tamper-proof chip, but it would never be able to work with things like Apple Pay. It would probably be able to do some things like log you in to your Mac by spoofing itself as a card reader or secure key. But because we can’t communicate with Apple’s Secure Enclave it would never be a seamless experience.

Maybe someday Apple could open up Touch ID like they do with Find My. But for now it’s pretty much a non-starter.