Errors

Errors let you define consistent domain/application errors in one place. They are useful for keeping error code and status conventions aligned across services.

Basic Syntax

Use error followed by the error name and a property block.

error UserNotFoundError {
    message: "User not found"
    code: "USER_NOT_FOUND_ERR"
    status: 404
}

Properties

Supported properties:

• message (required): string literal
• code (optional): string literal
• scope (optional): string literal
• status (optional): string literal or number literal

Type checker rules:

1. message is required.
2. code must be string if provided.
3. scope must be string if provided.
4. status must be string or number if provided.

The parser only accepts literal values here. You cannot use a model field, variable, or expression.

Example

error SignInInformationIncorrectError {
    message: "Sign-in information incorrect"
    code: "SIGNIN_INFO_INCORRECT_ERR"
    status: 400
}

error AuthorizationError {
    message: "Unauthenticated"
    code: "AUTHORIZATION_ERR"
    status: "401"
    scope: "auth"
}

Invalid Examples

error BrokenError {
    code: "BROKEN_ERR"
    status: 500
}

This fails because message is required.

error BadStatusError {
    message: "Bad"
    status: true
}

This fails because status must be a string or number literal.

error BadCodeError {
    message: "Bad"
    code: 123
}

This fails because code must be a string literal.

Common Mistakes

1. Omitting message.
2. Using non-literal values for properties.
3. Using unknown properties in error blocks.