Interesting. 🤨 While the Supreme Court declined to rule on whether APIs are subject to copyright, it ruled in Oracle v. Google in 2021 that, depending on certain factors, re-implementation of an API, particularly for the purpose of connecting and extending products, is protected under fair use.

https://arstechnica.com/tech-policy/2021/04/how-the-supreme-court-saved-the-software-industry-from-api-copyrights/