Nike will unleash the application programming interface (API) for NikeFuel — the company's metric for tracking physical activity — during a music hackathon Sunday at South by Southwest.

NikeFuel is the technology behind Nike's FuelBand, a waterproof wristband introduced in January that measures a user's movement and syncs with an iPod touch or iPhone.

The API will allow third-party music developers to infuse NikeFuel features into their apps or platforms.

“Nike will be joining the Managers Hack to open up a BETA version of the NikeFuel API for the first time to developers interested in combining music with the Nike+ FuelBand,” hackathon organizer and rep at startup Backplane told Mashable Friday.

Backplane, which created Lady Gaga's new Little Monsters social network, along with music-streaming service Spotify organized the hackathon to build the future of digital music distribution.

At the event, hackers have eight hours to create and plan a demo that will be judged by a panel of music industry managers, including Lady Gaga’s manager Troy Carter (who co-founded Backplane), Justin Bieber's manager Scooter Braun and Roc Nation President Jay Brown. People from Spotify, Pandora, Nike and SoundHound also will help choose a winner.

The Managers Hack will be live streamed (see video below) starting at 3 p.m. ET.

Randi Zuckerberg, who left her role as marketing director at Facebook in August to launch RtoZ Media, will provide commentary throughout the event.

What Is Nike+ FuelBand?

Hands-On With the Nike+ FuelBand

What Is NikeFuel?