The New York City Council voted unanimously on Thursday to give freelance workers a set of protections against wage theft that are believed to be the first of their kind in the country.

Known as the Freelance Isn’t Free Act, the measure requires anyone hiring a freelance worker to agree in writing to a timetable and procedure for payment, and increases the potential awards to freelancers bringing legal complaints against those who have failed to pay them promptly.

The bill represents one of the earliest policy efforts to grapple directly with the growth in the so-called gig economy — a term that typically refers to the likes of temporary workers, contract workers, independent contractors and freelance workers. According to one estimate by the economists Lawrence Katz and Alan Krueger, this group grew to almost 16 percent of the work force in late 2015 from roughly 10 percent in early 2005.

“New York is in some ways at the center of the gig economy, of the evolution of the economy to more independent and contingent work,” Brad Lander, the councilman who introduced the legislation, said.