Jana Kramer has taken a pledge to help bring an end to domestic violence, and the actor and country singer is challenging her celebrity friends and fans to join in.

The singer and former star of TV's One Tree Hill posted to Instagram on Friday (Aug. 11) with her hands posed in front her, fists together and with both thumbs pointing downward. The nail of her ring finger is painted purple.

"Not long ago, I decided to share my experiences with domestic violence. Putting it out in the world was painful and difficult, and I wasn’t sure if I was ready," Kramer writes, adding that she has gained "peace, healing, and even strength in using my voice to speak out."

Kramer married her first husband, Michael Gambino, in 2004, and in 2016 she revealed that he abused her so badly that he was sent to prison for attempted murder for the violence she suffered at his hands. Gambino choked Kramer so intensely in 2005 that she lapsed into unconsciousness, then abandoned her outside their L.A. home.

"I’m taking the vow to #PutTheNailinIt to end domestic violence and the silence around it. Please join me, donate to @SafeHorizon to help victims, paint your ring fingernail purple to show your support, using the hashtag #PutTheNailinIt to share your vow," she urges fans, challenging Kellie Pickler, Andy Grammer and Sophia Bush to take the vow, too.

"Together we can spark a conversation that could save a life," Kramer states.

The singer gave birth to daughter Jolie in January of 2016. She split from her third husband, football player Mike Caussin, in August of 2016, but lately the couple have posted pictures together on social media. On July 30 Kramer shared a picture of herself and Caussin in the park with their daughter and their dog, writing, “Park mornings with our girl,” and adding the hashtags #modernfamily and #daybyday.

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