The agent, who has been dating Spears since 2009, made the news official in a text to his friend and TV anchor Billy Bush, reports contactmusic.com.
“Yes, we are engaged,” wrote Trawick, adding that he was “over the moon”.
Trawick revealed he proposed to the singer in front of her sons — Sean Preston, six, and Jayden James, five, so that they could witness the special moment.
Spears also indirectly confirmed the good news through a post on micro-blogging site Twitter.
“Omg (Oh my god). Last night Jason surprised me with the one gift I’ve been waiting for. Can’t wait to show you!” tweeted Spears.
Trawick proposed during a dinner to celebrate his 40th birthday Thursday night.
The couple has been dating for two years.
Spears, popular for songs like “Baby one more time” and “Toxic”, was previously married to dancer Kevin Federline for two years, with whom she has two children.
The singer also spontaneously married childhood friend Jason Alexander during a trip to Las Vegas in 2004. That marriage lasted 55 hours before the singer annulled the union.