> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gu1.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# List itemData keys

> List the distinct keys used inside the itemData payload of a data list, useful for driving column configuration in UIs — GET /data-lists/{id}/item-data-keys.

## Overview

Returns the set of **itemData** keys observed on items (used by UIs to configure optional columns). May scan the list in the database.

## Endpoint

```
GET https://api.gu1.ai/data-lists/{id}/item-data-keys
```

## Authentication

```bash theme={null}
Authorization: Bearer YOUR_API_KEY
```

## Response

```json theme={null}
{
  "success": true,
  "itemDataKeys": ["columnA", "columnB"]
}
```

`403` when the list is not accessible via this API (e.g. certain marketplace global lists).