California introduces age verification law for all operating systems, including Linux and SteamOS — user age verified during OS account setup

Source: Tom’s Hardware

Overview

California’s Digital Age Assurance Act (AB 1043) was signed by Governor Gavin Newsom in October 2025. The law requires every operating‑system provider in California to collect age information from users during account setup and to transmit that data to app developers via a real‑time API. The provisions take effect on January 1, 2027.

Scope of the Law

The statute defines an “operating system provider” broadly as anyone who develops, licenses, or controls the operating‑system software on a computer, mobile device, or any other general‑purpose computing device. This definition encompasses:

• Windows
• macOS
• Android and iOS
• Linux distributions
• Valve’s SteamOS

Age‑Verification Requirements

• OS providers must maintain a reasonably consistent real‑time application programming interface (API).

• The API must categorize users into four age brackets:

  1. Under 13
  2. 13 to under 16
  3. 16 to under 18
  4. 18 or older

• When an app is downloaded or launched, the provider must supply the appropriate age signal to any developer that requests it.

Implications for Linux and SteamOS

Because Linux distributions and SteamOS fall under the definition of “operating system provider,” their maintainers will need to implement the age‑verification API and integrate it into their user‑account creation flows. This represents a significant shift for open‑source and gaming platforms that have traditionally not collected personal age data at the OS level.

References

• California Digital Age Assurance Act (AB 1043) – Full Text
• Valve’s SteamOS required to register credit card for adult content (Tom’s Hardware)