ATTACHES an audience to a campaign or ad group (or removes it) — the missing link that makes your audience lists actually do something. Creating a remarketing/customer-match/lookalike list does NOT affect delivery until it is attached to a campaign; until now they were built but never connected.

audience = one of TWO different things, and the tool works out which: • YOUR OWN remarketing / customer-match / lookalike list — name or ID from list_audiences. Works at campaign AND ad-group level. • A GOOGLE-DEFINED segment — an in-market, affinity, life-event or detailed-demographic audience, given by its EXACT display name as it appears in reports and in the Google Ads interface (e.g. "Network & Enterprise Security", "Large Employer (250-10k Employees)"), or as customers/…/userInterests/92507. Campaign and ad-group level both work. Two limits come from Google: a detailed-demographic CATEGORY cannot be attached, only a leaf inside it ("Large Employer (250-10k Employees)" works, "Company Size" does not), and life-event segments are refused on Search campaigns — they exist for Display, Video and Demand Gen. NOTE: the criterion_id in an audience report is NOT the segment id — do not pass it here; pass the name. Give campaign_id OR ad_group_id. action: • attach = add the audience as a POSITIVE criterion (observe/bid on it). • exclude = add it as a NEGATIVE criterion (negative=true) → do NOT show ads to this audience (e.g. exclude people who already converted / clicked call/WhatsApp). Works at campaign AND ad-group level. • remove = detach the positive audience criterion. • remove_exclusion = remove a previously excluded audience. (remove/remove_exclusion find the exact criterion by this audience + negative flag, so the right one is removed.) mode (positive attach only): OBSERVATION = don't narrow reach, just report/bid (safe default). TARGETING = restrict reach to only the attached audiences (e.g. a search remarketing / RLSA campaign shown only to site visitors). TARGETING is a setting of the whole campaign or ad group: it narrows delivery to ALL positive audiences attached at that level, and its other targeting restrictions are kept. Empty mode = OBSERVATION for a new audience and leaves the existing setting unchanged. If the audience is already attached, attach with mode=TARGETING just switches the setting, and attach with mode=OBSERVATION switches it back to observation. bid_modifier: optional bid multiplier for a POSITIVE audience, e.g. 1.2 = +20% (invalid for exclude; 0 = none). confirm=false previews.