You bet!

you bet

You can be sure; absolutely; definitely. A: "Hey Frank, do you want to come with us to the movies?" B: "You bet I do!" A: "Is it OK if Frank brings his girlfriend?" B: "You bet! Tommy's bringing Sarah as well, so it's no problem at all."
See also: bet
Farlex Dictionary of Idioms.

You bet!

 
1. Inf. Yes. Tom: Are you coming to the party? Jane: You bet! Charlie: May I borrow your hammer? Mary: You bet!
2. Inf. You're welcome. Tom: Thank you. Jane: You bet. Sally: I appreciate it. Mary: You bet.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • you bet
  • betcha
  • you betcha
  • You betcha!
  • you bet your bottom
  • straight out
  • have it out (with someone)
  • have it out with somebody
  • have it out with someone
  • talk turkey, to