Create Lookalike Audience - Markifact

Create a Meta lookalike audience from an existing source custom audience. Use meta_list_custom_audiences first to find origin_audience_id. The origin audience must have at least 100 people.


App	Meta Ads
Operation ID	`meta_create_lookalike_audience`
Type	Action
Connection	`meta_ads` (required)
Credits per run	2
Agent / MCP tool	Yes
Requires approval	Yes (write operation)

Inputs

Field	Type	Required	Default	Description
`account`	DynamicAccount	Yes	-	Select Meta Ads account, ask the user for it if not provided.
`name`	string	Yes	-	Name for the lookalike audience.
`description`	string	No	-	Optional audience description.
`origin_audience_id`	string or SelectItem	Yes	-	Source custom audience ID used as the seed. Use meta_list_custom_audiences to find it. Meta requires the origin audience to have at least 100 people.
`country`	string or SelectItem	No	-	Two-letter country code for the simple lookalike spec, e.g. US, AE, GB. Required unless lookalike_spec is provided.
`ratio`	number	No	`0.01`	Simple lookalike size as a decimal from 0.01 to 0.20 in 0.01 increments. 0.01 means the top 1% most similar audience in the selected country.
`starting_ratio`	number	No	-	Optional start percentage for a lookalike range. Example: starting_ratio=0.01 and ratio=0.02 creates a 1%-2% lookalike. Must be less than ratio.
`allow_international_seeds`	boolean	No	-	Optional Meta flag for simple specs. If true, Meta can use seed members from another country when the selected country has fewer than 100 seed members.
`lookalike_spec`	object or string	No	-	Advanced Meta lookalike_spec object as a dict/object or string. Use this only when simple country/ratio fields are not enough. Must include either country or location_spec, and either ratio or type. Examples: {‘country’: ‘US’, ‘ratio’: 0.01}; {‘country’: ‘US’, ‘starting_ratio’: 0.01, ‘ratio’: 0.02}; {‘location_spec’: {‘geo_locations’: {‘countries’: [‘US’, ‘CA’]}}, ‘ratio’: 0.01}; {‘country’: ‘US’, ‘type’: ‘similarity’}. Do not include origin_audience_id, account_id, name, or subtype.

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.

Output

Type: Dict Returns created lookalike audience id and name. Fields: audience_id, name