by Mona Truong, Murror*
California's SB 243 took effect this year. The definition is broader than the word "companion" sounds, and most of what it asks for is stuff a decent builder would want to ship anyway.
If you're building anything where a person talks to your AI about their life — a journaling tool, a coaching app, a "supportive" assistant, a character — there's a law worth reading this month, and it's probably not the one you think. Not the EU AI Act. A California statute called SB 243. It took effect January 1st, and I'd bet most makers in this space haven't checked whether they're inside its fence. The reason to care isn't that the penalty is scary (though it's real). It's that the law quietly wrote down a definition of "companion chatbot," and the definition is broad enough that a lot of products land inside it by accident.
Here's the definition, roughly: an AI that gives adaptive, human-like responses, is capable of meeting a user's social needs, has some anthropomorphic feel to it, and can sustain a relationship across multiple sessions. Read that again as a builder, not a lawyer. "Human-like responses" is every LLM. "Sustains a relationship across sessions" is any product with memory. "Meets social needs" is the part people wave away — "we're a productivity tool, not a companion" — but if your users keep coming back to talk and feel a little better after, the label on your landing page won't be what decides it. There are carveouts (pure customer-service bots, game NPCs that can't discuss mental health, plain voice assistants), but the middle is fuzzy on purpose, and fuzzy-on-purpose is exactly where indie products live.
If you're in scope, here's what SB 243 actually requires.
*This is not legal advice.