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

# Extract Keys

> Extract the keys of objects from an array of child objects

The Extract Keys command (Command Type: 1011) extracts the keys of objects from an array of child objects and returns them in a simplified format.

## Overview

The Extract Keys command provides functionality for:

* Extracting object keys from nested child arrays
* Wrapping extracted keys under a specified property name
* Simplifying complex nested structures

## Command Type

**Command Type ID:** 1011

## Parameters

| Parameter    | Type   | Description                                                                | Required |
| ------------ | ------ | -------------------------------------------------------------------------- | -------- |
| **childKey** | string | The property name to use as a wrapper for the extracted keys in the output | Yes      |

## Usage Examples

### Extract Keys from Children

```json theme={null}
{
  "command": "extract-keys",
  "params": {
    "childKey": "markets"
  }
}
```

### Extract Keys with Custom Wrapper

```json theme={null}
{
  "command": "extract-keys",
  "params": {
    "childKey": "attributes"
  }
}
```

## Common Use Cases

* **Structure Simplification**: Flatten nested object key arrays into a simpler format
* **Key Discovery**: Extract what keys are present in dynamic or schema-less child objects
* **Pipeline Preparation**: Prepare key lists for downstream mapping or filtering

## Related Commands

* [Key Mapping](/stream/commands/parse/key-mapping) - Map extracted keys to new names
* [Json Path](/stream/commands/parse/json-path) - Navigate into extracted structures
* [Object Mapper](/stream/commands/parse/object-mapper) - Transform extracted key output