# active is not a CSV column

CSV from a nested JSON object does not explode inner keys into headers. On the [JSON converter](https://kepttools.com/json-converter), only top-level keys become columns. A nested object is one cell. Inner quotes are doubled so the row stays valid CSV. Conversion runs in the browser.

Paste the sample array and pick CSV. `meta` is a column. `active` is not.

```csv
id,name,role,meta
1,Ada,engineer,"{""active"":true}"
2,Linus,founder,"{""active"":false}"
```

An array value follows the same rule. `{"id":1,"tags":[]}` writes a `tags` cell of `[]`.

## TypeScript still names the nest

TypeScript does not flatten `meta` either, but it does draft a child interface from the first object:

```ts
export interface Root {
  id: number;
  name: string;
  role: string;
  meta: Meta;
}

export interface Meta {
  active: boolean;
}
```

The PHP DTO types the same field as `public array $meta`. No second class is emitted. Laravel nests a PHP array under `'meta'`. If you open the CSV in a sheet and look for an `active` column, you will not find one. The boolean is still inside the JSON string in the `meta` cell.

## Empty array and broken paste

CSV rejects `[]` with `CSV conversion expects an array of objects.` Laravel still prints `[]`. TypeScript prints an empty `Root`. The PHP class stays named `DataTransferObject` with no properties. A trailing comma clears the output entirely: `{"a":1,}` yields `Expected double-quoted property name in JSON at position 7 (line 1 column 8)`. Fix the text in the [JSON formatter](https://kepttools.com/json-formatter) before you convert again.

Treat CSV as a top-level export. Treat the TypeScript and PHP blocks as drafts you rename and harden before they ship.

Guide: <https://kepttools.com/guides/json-to-typescript-php-dto-laravel>