Errors are an inevitable part of API integration, and providing not only a robust set of clear and meaningful API error response codes, but a clear listing of these codes for developers to follow and learn from is essential.

API errors are directly related to frustration during developer integration, the more friendly and meaningful they are, the greater the chance a developer will move forward after encountering an error. Put a lot of consideration into your error responses and the documentation that educates developers.

Source: US OD