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

# Update Custom Audience Users

> Adds or removes users in a Reddit Ads custom audience using emails or mobile advertising IDs (hashed automatically); one identifier kind per call

Adds or removes users in a Reddit Ads custom audience using emails or mobile advertising IDs (hashed automatically); one identifier kind per call. Find audience IDs with reddit\_ads\_list\_custom\_audiences.

|                       |                                           |
| --------------------- | ----------------------------------------- |
| **App**               | Reddit Ads                                |
| **Operation ID**      | `reddit_ads_update_custom_audience_users` |
| **Type**              | Action                                    |
| **Connection**        | `reddit_ads` (required)                   |
| **Credits per run**   | 1                                         |
| **Agent / MCP tool**  | Yes                                       |
| **Requires approval** | Yes (write operation)                     |

## Inputs

| Field               | Type                       | Required | Default | Description                                                                                                                                                                                                                                       |
| ------------------- | -------------------------- | -------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `account`           | DynamicAccount             | Yes      | -       | Select the Reddit Ads account that owns the audience.                                                                                                                                                                                             |
| `audience_id`       | string or SelectItem       | Yes      | -       | ID of the custom audience to update. Find audience IDs with reddit\_ads\_list\_custom\_audiences.                                                                                                                                                 |
| `action`            | string or SelectableOption | Yes      | -       | Whether to add or remove the users. Options: 'ADD', 'REMOVE'.                                                                                                                                                                                     |
| `emails`            | string or array of string  | No       | -       | Email addresses as a list or comma/newline separated text. Plain emails are normalized (whitespace removed, lowercased) and SHA-256 hashed automatically; already-hashed 64-hex values pass through. Use emails or mobile\_device\_ids, not both. |
| `mobile_device_ids` | string or array of string  | No       | -       | Mobile advertising IDs (IDFA / AAID) as a list or comma/newline separated text; hashed automatically. Use emails or mobile\_device\_ids, not both.                                                                                                |

### SelectItem

| Field   | Type   | Required | Default | Description                                                                                          |
| ------- | ------ | -------- | ------- | ---------------------------------------------------------------------------------------------------- |
| `value` | string | Yes      | -       | The value of the selectable item.                                                                    |
| `label` | string | Yes      | -       | The label of the selectable item, used for display purposes. If not provided, defaults to the value. |

### SelectableOption

| Field   | Type   | Required | Default | Description |
| ------- | ------ | -------- | ------- | ----------- |
| `value` | string | Yes      | -       |             |
| `label` | string | Yes      | -       |             |

## Output

**Type**: `Dict`

Returns the action and user counts.

**Fields**: `audience_id`, `action`, `identifier_type`, `user_count`