(I'd be) happy to (do something)
Glad or eager to do something. Sure, I'd be happy to help! What do you need? Always happy to help.
(I'd be) happy to (do something).
and Be happy to (do something).I would do it with pleasure. (The something is often replaced with a description of an activity.) John: I tried to get the book you wanted, but they didn't have it. Shall I try another store? Mary: No, never mind. John: I'd be happy to give it a try. Alice: Would you fix this, please? John: Be happy to.