How do I know this?
Because Tanney posted a picture of it on Twitter:
The photo comes via The Register-Mail in Galesburg, Illinois, who posted the screen-grab. Presumably it's just the standard player contract with nothing fancy in it. Rookie free agents usually don't receive much if anything in the way of signing bonuses or guaranteed money (and "not much" is a relative term...I'd suit up for the Chiefs this offseason for like $80).
Whether it's one year or three years, fourth string quarterbacks signed in June often don't even make the final roster.