California's Bot Disclosure Act (SB 1001, effective July 1, 2019) requires anyone operating an automated online account to clearly and conspicuously disclose that it is a bot if they are using the bot to mislead people about its artificial identity for the purpose of inducing a commercial purchase or influencing a vote in an election.
A "bot" is defined as "an automated online account where all or substantially all of the actions or posts of that account are not the result of a person." The law was the first US bot-disclosure statute and continues to inform broader state-level AI transparency rulemaking.