Sources with direct knowledge tell TMZ ... Nikki has been making calls since Friday, and we're told her intention is to file to end her marriage to Artem Chigvintsev.

Nikki began the search a day after Artem allegedly attacked her, resulting in some physical injury that triggered his arrest for felony domestic violence.

As we reported, Nikki has not been wearing her wedding ring since the incident. She hosted the Chestnut/Kobayashi hot dog eating contest over the weekend in Vegas, and her finger was bare.

Our sources also say Artem is not staying at the family home ... we're told he's been staying at a friend's house. Nikki is in the family house with their 4-year-old son Matteo.

TMZ broke the story ... Artem was arrested Thursday for felony corporal injury to a spouse or cohabitant after he called paramedics to request medical assistance for the alleged victim. Radio dispatch audio confirms he called for, then canceled, the visit ... but cops still showed up at the house.

Officers say they observed obvious injuries on the victim's body, and they arrested Artem for the felony. He was released on bail hours after his arrest.

Nikki and Artem met in 2017 when they competed together on season 28 of "Dancing with the Stars" ... kicking off a romantic relationship several years later when she split with John Cena.

Their son Matteo was born in 2020, and the 2 married in 2022 ... celebrating their second anniversary just days before AC's arrest.