Epic Games announced this week that it is launching the Fortnite Data API, which makes several data points about Fortnite islands public for creators to access. This data includes engagement and retention metrics, allowing other creators to better understand what makes certain kinds of games successful with players. According to Epic, it plans to reveal more about the data’s uses at the upcoming Unreal Fest in Orlando.

The Fortnite Data API includes various data points on each island, including:

• Total minutes played by all players
• Average total minutes per unique player
• Number of game sessions played
• Number of times players favorited the island
• Number of times players recommended the island (previously “Likes”)
• Peak concurrent player count
• Number of distinct players
• Day-over-day retention
• Week-over-week retention

Each of these data points is available for third-party analysis and insights, for a period of up to seven days. It’s publicly accessible and doesn’t require authentication to access.

According to Epic’s FAQ, this new change only applies to islands made by Epic itself, including Fortnite Battle Royale, at least currently. On June 9, it plans to expand to include all creator-made islands, and the same FAQ also notes that there’s no way for creators to opt out of the sharing of this information: “Data transparency applies equally to all islands published in the Fortnite ecosystem, which is why we’re sharing data from Epic-made islands as well.”