# meta_add_custom_audience_users

> Add people to a customer-list (CUSTOM) audience of the selected account.

[Documentation](https://www.getmcpads.com/docs) / [Sources](https://www.getmcpads.com/docs/sources) / [Meta Ads](https://www.getmcpads.com/docs/sources/meta-ads)

Add people to a customer-list (CUSTOM) audience of the selected account. Emails and international phones are normalized and SHA-256 hashed by the server, as Meta requires; the preview and the answer carry counts, never the values. The ad account must belong to a Business and have accepted the Custom Audience terms (Meta refuses otherwise). Matching takes up to 24 hours, and a list serves only once Meta finds enough people. Local preview by default. No automatic retry. Account ownership is checked before Meta validation or mutation.

> **Warning** This tool changes the account. It is absent from the tool list on the Free plan, and it previews by default: without `confirm: true` it describes the change and applies nothing.

|  |  |
| --- | --- |
| Source | [Meta Ads](https://www.getmcpads.com/docs/sources/meta-ads) |
| Kind | Write |
| Discovery | Reachable through `search_tools` and `run_tool` |
| Account parameter | `adAccountId` |
| Endpoint | https://mcp.getmcpads.com/meta-ads/mcp |

## Parameters

| Name | Type | Required | Notes |
| --- | --- | --- | --- |
| `adAccountId` | string | Required | Selected owning ad account ID, with or without act_. Every referenced ad object must belong to it. |
| `audienceId` | string | Required | Numeric ID of the existing custom audience in this selected ad account. |
| `members` | array | Required | People who agreed to it: an email and/or an international phone each. Hashed by the server; raw values are never sent to Meta, returned or logged. |
| `confirm` | boolean | Optional | Apply only when true. Default is a local preview with no API mutation. |
| `validateOnly` | boolean | Optional | Ask Meta to validate, without creating or changing an object. Mutually exclusive with confirm. |

## Calling it

Through run_tool, since it is not announced

```json
{
  "name": "run_tool",
  "arguments": {
    "name": "meta_add_custom_audience_users",
    "args": {
      "adAccountId": "<string>",
      "audienceId": "<string>",
      "members": "<array>"
    }
  }
}
```

- [Meta Ads metrics](https://www.getmcpads.com/docs/sources/meta-ads/metrics): What you can ask for.
- [Meta Ads dimensions](https://www.getmcpads.com/docs/sources/meta-ads/dimensions): How you can break it down.

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