Client libraries. Release and support good client libraries for popular programming languages. This is way more important than documenting your API at all. N

Client libraries. Release and support good client libraries for popular programming languages. This is way more important than documenting your API at all. Nobody likes having to read the gory details of how your API works and having to write a HTTP client around it. And everytime they do, error handling is badly handled, if at all. People want to start using your service right away. They want to just call one function to do a thing, without having to worry about how it works underneath. Even if this is not HTTP, think about MySQL. Used everywhere, via tons of different programming languages. Yet virtually no one knows how the protocol ("API") works. And this is completely fine. Having good client libraries also allows updating the protocol without requiring users to change their apps.