One way to create globally available custom errors as a service in SailsJS

CustomErrors.js

'use strict';

/**
 * Indicates an error where an invalid argument or input to a method.
 * @param {string} message The error message.
 * @param {string} stack   The stack trace.
 */
function InvalidArgumentException(message, stack) {
	this.name = 'InvalidArgumentException';
	this.message = message || 'Invalid Argument';
	this.stack = stack;
}
InvalidArgumentException.prototype = new Error();
InvalidArgumentException.prototype.constructor = InvalidArgumentException;

module.exports = {

	InvalidArgumentException: InvalidArgumentException

}

You'd place this file in your api/services directory, and then you would the do this later on:

throw new CustomErrors.InvalidArgumentException('Invalid argument', new Error().stack);