[1] After a few "unremarkable gigs" as a musical duo, guitarist Tony Smith and drummer Justin Wilson recruited the young Alex Kandel as a vocalist after discovering her working as a barista and, "doing Adele covers on open-mic nights."

They were invited to play The Weezer Cruise in January 2012 pairing them with musical acts such as Dinosaur Jr., Sebadoh, and Wavves.

Sleeper Agent played the Coachella Valley Music and Arts Festival in Indio, California, on April 15 and 22, 2012.

Sleeper Agent also played the Starry Nights Music Festival (hosted by Cage the Elephant) outside of Bowling Green, in late September 2012.

That same month, singer Alex Kandel was nominated for the Women who Rock competition for a spot on the cover of Rolling Stone.

On September 29, 2015, Tony Smith had posted a picture of the band on Sleeper Agents Facebook and Twitter reading "2010-2015".

Rolling Stone described the band as "Shaggy Kentucky kids whose songs are sweet, fizzy, and combustible as a can of shook soda."