This arrived on a few distro-specific lists, but it seems to me to be very much a cross-distro sort of problem. So reposting here to make people aware. There has been a fair amount of discussion following this initial mail and a more concrete and juristiction-agnostic proposal is promised. Take a look at, say https://lists.ubuntu.com/archives/ubuntu-devel/2026-March/thread.html#43515 to follow discussion so far.

----- Forwarded message from Aaron Rainbolt arraybolt3@gmail.com -----

From: Aaron Rainbolt arraybolt3@gmail.com Date: Sun, 1 Mar 2026 14:48:00 -0500 To: xdg@lists.freedesktop.org Cc: debian-devel@lists.debian.org, devel@lists.fedoraproject.org, ubuntu-devel@lists.ubuntu.com, debian-legal@lists.debian.org, legal@lists.fedoraproject.org, adrelanos@whonix.org Subject: On the unfortunate need for an "age verification" API for legal compliance reasons in some U.S. states List-Id: <debian-devel.lists.debian.org>

Given that this is related to legal stuff, I should preface this by saying I am not a lawyer.

Recently, a new law was passed in California that requires OS vendors to provide some limited info about a user's age via an API that application distribution websites and application stores can use. [1] Colorado seems to be working on a similar law. [2] The law will go into effect January 1, 2027, it is no longer a draft. I do quite a bit of work with an OS vendor (working with the Kicksecure [3] and Whonix [4] projects), and we aren't particularly interested in blocking everyone in California and Colorado from using our OSes, so we're currently looking into how to implement an API that will comply with the laws while also not being a privacy disaster. Given that other distributions are also investigating what to do with this, and the law requires us to make a "good faith effort to comply with [the] title, taking into consideration available technology", I figured it would be a good idea to bring the issue here.

At its core, the law seems to require that an "operating system" (I'm guessing this would correspond to a Linux distribution, not an OS kernel or userland) request the user's age or date of birth at "account setup". The OS is also expected to allow users to set the user's age if they didn't already provide it (because the OS was installed before the law went into effect), and it needs to provide an API somewhere so that app stores and application distribution websites can ask the OS "what age bracket does this user fall into?" Four age brackets are defined, "< 13", ">= 13 and < 16", ">= 16 and < 18", and ">= 18". It looks like the API also needs to not provide more information than just the age bracket data. A bunch of stuff is left unclear (how to handle servers and other CLI-only installs, how to handle VMs, whether the law is even applicable if the primary user is over 18 since the law ridiculously defines a user as "a child" while also defining "a child" as anyone under the age of 18, etc.), but that's what we're given to deal with.

The most intuitive place to put this functionality would be, IMO, AccountsService. The main issue with that is that stable-release distributions, and distributions based upon them, would be faced with the issue of how to get an updated version of AccountsService integrated into their software repositories, or how to backport the appropriate code. The law goes into effect on January 1, 2027, Debian Bookworm is going to be supported by ELTS until July 30, 2033, and we don't yet know if Debian will care enough about California's laws to want to backport a new feature in AccountsService into Debian Bookworm (or even Trixie). Distributions based on Debian (such as Kicksecure and Whonix) may still want to comply with the law though, so something using AccountsService-specific APIs would be frustrating. Requiring a whole separate daemon for the foreseeable future just for an age verification API would also be annoying.

Another place the functionality could go is xdg-desktop-portal. This one is a bit non-ideal for a couple of reasons; for one, the easiest place to put the call would be in the Account portal, which returns more information than the account's age bracket. This could potentially be considered non-compliant with the law, as it states that the operating system shall "[s]end only the minimum amount of information necessary to comply with this title". This also comes with the backporting disadvantages of an AccountsService-based implementation.

For this reason, I'd like to propose a "hybrid" approach; introduce a new standard D-Bus interface, `org.freedesktop.AgeVerification1`, that can be implemented by arbitrary applications as a distro sees fit. AccountsService could implement this API so that newer versions of distros will get the relevant features for free, while distros with an AccountsService too old to contain the feature can implement it themselves as a stop-gap solution.

Taking inspiration from the File Manager D-Bus interface [5], I think something like the following might work:

<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd"> <node name="/org/freedesktop/AgeVerification1"> <interface name="org.freedesktop.AgeVerification1"> <method name="SetAge"> <arg type="s" name="User" direction="in"/> <arg type="u" name="YearsOfAge" direction="in"/> </method> <method name="SetDateOfBirth"> <arg type="s" name="User" direction="in"/> <arg type="s" name="Date" direction="in"/> </method> <method name='GetAgeBracket'> <arg type="s" name="User" direction="in"/> <arg type="u" name="AgeBracket" direction="out"/> </method> </interface> </node>

* The 'User' argument would, in all instances, be expected to be the UNIX account username of the user in question. This user account must not be a system account (i.e. its UID must fall between UID_MIN and UID_MAX as defined by /etc/login.defs). If a user is specified that does not exist or whose UID is out of range, these methods will return the error 'org.freedesktop.AgeVerification1.Error.NoSuchUser'. If the specified user is not the same as the user making the method call, and the user making the method call is not root, these methods will return the error 'org.freedesktop.AgeVerification1.Error.PermissionDenied'. * The 'YearsOfAge' argument of the 'SetAge' method should be an unsigned integer specifying the age of the user in years at the time of the method call. (The law specifically allows providing simply an age value rather than a birth date if desired.) * The 'Date' argument of the 'SetDateOfBirth' method should be a string in ISO8601 format (i.e. YYYY-MM-DD) indicating the day on which the user was born. If the argument is invalid, the method will return the error 'org.freedesktop.AgeVerification1.Error.InvalidDate'. * The 'AgeBracket' output argument of the 'GetAgeBracket' method will be an unsigned integer between 1 and 4 inclusive, where 1 indicates that the user is under 13 years old, 2 indicates that the user is at least 13 and under 16 years old, 3 indicates that the user is at least 16 and under 18 years old, and 4 indicates that the user is 18 years old or older. If no age has been configured for the user yet, the method will return the error 'org.freedesktop.AgeVerification1.Error.AgeUndefined'.

I propose that the exact way in which age information is stored by the daemon should be left implementation-defined. For Kicksecure, the way we implement it will almost certainly store only the age bracket and require users to explicitly reconfigure their age once they are old enough to move from one age bracket to another. Other implementations may choose to store the date of birth or the age and date on which the age was set so that they can automatically update the age bracket as time passes. This interface will be provided *on the system bus* (NOT the session bus!), and the D-Bus service that provides these services should run as root. The file containing the user-to-age mappings should be owned by root and should not be world-readable, to prevent leaking the user's specific age to malicious applications.

Some things I did think about when writing the above but ultimately decided to not propose:

* Detailed permission gating for the 'GetAgeBracket' method. The only reason to do this would be for additional privacy, and privacy-conscious users can simply lie about their age or the age of the intended user. There isn't anything in the law (that I can tell) that prevents the user from just saying "I'm 18" when the prompt appears and going with it. This would also be really difficult to implement outside of the context of xdg-desktop-portal, and would probably only work with sandboxed apps if it was implemented that way. * UX for actually requesting the age from the user. IMO this is out of scope for FreeDesktop; individual distros should see to it that they prompt for the user's age or birth date at "account setup" (whatever that happens to be defined as for the distro in question), nudge the user to provide the information later on for existing installations, etc. Furthermore, this mechanism needs to work even on CLI-only installs and maybe even on server installs, depending on how one defines "general purpose computing device" (as specified by the law in question), so defining any specific UX is likely infeasible. (If this is required on servers, end-users will probably want to auto-provision the age information somehow, and specifying how to do that in a distribution-agnostic way is impossible given that Ubuntu uses cloud-init, Fedora uses Kickstart and Ignition, etc.) * Omitting the 'SetDateOfBirth' method. It can be lived without legally, but without the method, it becomes difficult for software that already records the user's date of birth to accurately implement automatic age bracket adjustment as time passes. This isn't a feature Kicksecure would use, but it's a feature some projects might be interested in.

Thanks for taking a look at this.

-- Aaron

[1] https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202520... [2] https://leg.colorado.gov/bill_files/110990/download [3] https://www.kicksecure.com/ [4] https://www.whonix.org/ [5] https://www.freedesktop.org/wiki/Specifications/file-manager-interface/

----- End forwarded message ----- Wookey