Discover audiences from a segment catalog

Third-party audiences on Adprime Zero come from a real catalog of 43,175 segment rows across 13 provider ids. You search, you pick returned ids, and unknown keys are rejected.

The catalog was expanded on June 25, 2026 from a 50-row seed by a live refresh from the exchange. It is not a guessed list of friendly names.

Dashboard targeting, GET /targeting/reference/segments, and the discover_segments tool all read the same catalog. Query by the words you mean, set a limit, and read the results.

Use the returned id as the segment key. Do not type the display name into create_targeting. Show estimated data CPM and reach before you create the targeting set. Data CPM is part of the buy. Hiding it until the first invoice is how a "cheap" remnant test stops being cheap.

POST /targeting and MCP create_targeting resolve every submitted segment key into audit rows with data CPM, reach, and policy tier. An unknown key fails the request. It is not dropped. Dropping was the failure mode we refused, because an agent that sends a typo would launch a broader or empty audience and call it targeted.

Segments in a sensitive tier have to be reviewed and acknowledged before use, including when a chat asks for them. An agent may discover and propose. It should not attach a sensitive segment to a live campaign because a prompt said "find me buyers."

Activation still needs prepaid balance and the rest of the campaign checks. A segment-targeted campaign must not activate broader than requested. Segment targeting has been live in the product since June 25, 2026. Creating targeting returns a warning for any segment whose data provider has not yet served an ad on our exchange account, so check segment_summary.serving_warnings before you launch.

Geography is still set on the targeting object, as countries or as states and provinces. Segments do not replace "USA only" if that is what you meant.

It is not a promise that a named segment will convert. It is not a replacement for reading remnant quality after launch. A precise audience on a clicky domain is still a clicky domain. Read performance without fooling yourself still applies.

The Lab writeup of the same catalog is Segment targeting from a real catalog. This guide is the buyer job: search, pick ids, show CPM, refuse unknown keys.

Example REST shape from the public quickstart. Over MCP, the same two steps are discover_segments and create_targeting.

GET /targeting/reference/segments?q=automotive&limit=5

POST /targeting
{"name":"US auto intenders","geo":{"include_countries":["USA"]},"audience_segments":{"include_segments":["alliant-167430"],"exclude_segments":[]}}

Use a key you actually received from discover. The alliant-167430 example is a documented quickstart id, not a recommendation for your product.