InternalServerError creates a new API error representing an internal server error (HTTP 500).

InvalidData converts a data validation error into an API error (HTTP 400).

LoadMessages reads a YAML file containing error templates.

NewHTTPError creates a new APIError with the given HTTP status code, error code, and parameters for replacing placeholders in the error template.

NotFound creates a new API error representing a resource-not-found error (HTTP 404).

Unauthorized creates a new API error representing an authentication failure (HTTP 401).

APIError represents an error that can be sent in an error response.