Could I get a better rate?

Just got offer accepted less then a week ago. Everything is looking good and we struck one hell of a deal on this house thanks to my agent. He was the listing agent with the seller too and had a really great relationship with them. They worked together in the past!

Anyways, my question is, is it possible to get a better rate? I’m going through myVu(veterans united) conventional load 30yrs at 6.125%APR. Requires 5% down, and we got sellers assist as well. After downpayment and all that, total loan amount is less the $140k.

After reading some other people post on here, 6.125% APR seems pretty high. I did need a co signer due to my lack of work history. Both mine score (791), and my co-signers score (811) is extremely good. Should I shop around or ask myVU agent for more clarification on why APR is that high? We close first week of January if inspect goes well this week.