This guide contains a summary of best practices as well as some ideas to consider when writing an API for your library.
The guide is mostly authored by the Kotlin Libraries team, and is based on the practices the team follows when developing and maintaining Kotlin standard and official libraries.
You can read it at kotl.in/api-guide
You are welcome to join the discsussion about existing guidelines or to propose a new one. Feel free to join the discussions or submit your requests to issues.