SAN FRANCISCO — California Gov. Gavin Newsom signed a first-in-the-nation law on Monday that will force major AI companies to reveal their safety protocols — marking the end of a lobbying battle with big tech companies like ChatGPT maker OpenAI and Meta and setting the groundwork for a potential national standard.

The proposal was the second attempt by the author, ambitious San Francisco Democrat and state Sen. Scott Wiener, to pass such legislation after Newsom vetoed a broader measure last year that set off an international debate.