The deal is worth $600,000, a source told ESPN.com's Pierre LeBrun.
The Kings announced the deal Friday for Hunter, the longtime New York Islanders forward.
Hunter spent parts of the last nine seasons with the Islanders, scoring 229 points in 459 career games. He missed most of last season after surgery on his injured left knee, playing in just 17 games.
The Islanders traded Hunter in July to the New Jersey Devils, who waived him four days later. Hunter joined the Kings on a tryout contract two weeks ago, impressing coach Terry Murray in his bid to earn a roster spot as a depth forward.
Hunter has scored 99 career goals.
Information from The Associated Press was used in this report.