# Manage custom audience (create / update / delete) (adsap_manage_custom_audience)

Creates, updates or deletes a rule-based Meta custom audience: website visitors, Instagram or Facebook engagers, lookalikes of an existing audience, or app users.

Canonical: https://adsap.ai/docs/tools/adsap_manage_custom_audience
Updated: 2026-09-13

**Platform:** Meta · **Read or write:** Write · **Plan:** Early Access · **Consumes a task:** Yes · **Preview supported:** Yes

## What it does

Creates, updates or deletes a rule-based Meta custom audience: website visitors, Instagram or Facebook engagers, lookalikes of an existing audience, or app users. The first call is a preview; ask again to apply. Deleting is permanent and pauses any ad set that uses the audience, and the preview lists those ad sets first.

## Parameters

Descriptions are shortened from the tool schema. Your assistant sees the full text.

| Name | Type | Required | Description |
|---|---|---|---|
| `action` | one of `create`, `update`, `delete` | Yes | What to do: "create" a new rule-based audience, "update" an existing one's name/description/rule, or "delete" one permanently. |
| `ad_account_id` | string | Yes | act_<digits>. The ad account that owns (or will own) the custom audience. Used for ownership, workspace resolution, and Meta API budget. |
| `audience_type` | one of `website`, `engagement`, `lookalike`, `app` | No | Required for action=create. "website" = pixel/site visitors (WCA), "engagement" = people who engaged with your Instagram/Facebook (ECA), "lookalike" = people similar to an existing audience (LAL), "app" = mobile app users (MACA). |
| `name` | string | No | Required for action=create. The audience name shown in Ads Manager. |
| `rule` | string | No | Required for create when audience_type is website/engagement/app (NOT lookalike). A JSON-ENCODED STRING (not an object). Structure: \{"inclusions":\{"operator":"or","rules":[<rule>]\}\} (optional top-level "exclusions" with the same shape). |
| `description` | string | No | Optional description for the audience (create or update). |
| `prefill` | boolean | No | Optional (website/engagement/app create). TRUE backfills the audience with historical data. Defaults to Meta's default (true). |
| `origin_audience_id` | string | No | Required for create when audience_type=lookalike. The numeric id of the SEED audience to model on (a WEBSITE/ENGAGEMENT/APP/CUSTOM audience: NOT another lookalike). Get it from adsap_list_custom_audiences. |
| `ratio` | number | No | Lookalike only. Share of the population to match, 0.01 (1%, closest/smallest) to 0.20 (20%, broadest/largest). Defaults to 0.01. |
| `lookalike_country` | string | No | Lookalike only. ISO country code (e.g. "US", "FR", "GB"). DEPRECATED BY META (v26 / all versions from 2026-09-01): the API silently ignores it and creates a countryless parent lookalike... |
| `custom_audience_id` | string | No | Required for action=update and action=delete. The numeric id of the existing custom audience. Get it from adsap_list_custom_audiences. |
| `dry_run` | boolean | No | Preview only: the request is validated and the resolved payload returned, nothing is created or changed. |

## Example prompts

- "Create a website audience of everyone who visited the pricing page in the last 30 days."
- "Build a 1% lookalike of my Purchasers audience for the US."
- "Preview deleting the old Engagers 2024 audience and tell me which ad sets it would pause."

## Notes

Customer list uploads (hashed emails or phone numbers) are not supported here. The account must accept Meta's Custom Audience terms once before the first audience is created.

## Related tools

- `adsap_get_custom_audience_ads`: List the ads that use/target a given custom audience (live from Meta): each with its ad set and campaign id.
- `adsap_list_custom_audiences`: List custom audiences and saved audiences in a Meta ad account.

## Guide

Read [Audiences and targeting](/guides/launch/audiences) for the workflow around this tool, and the [Tool reference](/tools) for every tool.