The Magpies swooped for the 20-year-old after a Premier League ruling confirmed he was no longer tied to Everton.
The Toffees verbally agreed new terms with the ex-Plymouth Argyle man, although he never put pen-to-paper with the Merseysiders.
Hughton wasted little time in making his move for the midfielder and says his conscience is completely clear on the deal.
"We are fortunate to have signed Dan and we are delighted to have him on board," explained Hughton.
"We are 100 per cent sure that we've done everything appropriately."