Is it common to ask early employee of a startup to sign a contract containing non-compete clauses?
I am against our employee, but I have a little concern on our competitor as they have money to lure our employee away from our startup.
What are the fair terms?
Absolutely. Just make sure that the Non-compete isn't too strict, as that may drive away employees. I signed a non-compete when I started at my current job. I'm not allowed to work for a competitor while I'm still employed or for two years afterward.
However, we defined "competitor" very narrowly (only direct competitors, not all tech companies), so I'm not worried that it will be cumbersome if I decide to move on. However, it's still effective against those that would try and steal our employees.