# XO0412: empty wire name

A field's wire name (`name as "key": T`) is its JSON key or SqlRow column and cannot be empty. Write the key, or leave out `as` to use the field's name. See core 2.2.

## Example

```xo
struct User {
  name as "": Str
} derive Json
```

## Fix

```xo
struct User {
  name: Str
} derive Json
```

Run `xo explain XO0412` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).