alt Hacker NewsThat's not my understanding. This is what the bill says: Provide a developer who has requested a signal with respect to a particular user with a digital signal via a reasonably consistent real-time application programming interface that identifies [the age group].
So the app requests a signal (like, calling an API), and the OS returns the signal (returning the age group).
Regarding API vs installation lock, TBH I don't think the law concerns that level of details. An OS or app-store installation lock that checks app ratings can be considered as a valid implementation.
The California law is horrible because it forces everyone to let tech companies and governments decide what's suitable for children, rather than let parents decide. It's telling parents to give every app their child's age and trust that the apps will do the right thing. It also legitimizes personal data collection (in this case, the user's age) for every app and service on the Internet that wants to know your age.
The password-based app installation lock I proposed in my original comment doesn't require any kind of age checking at all, so it naturally doesn't fit the California law. The device owner (in this case, the parent who buys the device for their child) gets to decide what apps can be installed on their child's phone on an app-by-app basis using a password set by the parent. The app store doesn't need to know, and the apps don't need to know.