Count the events for a pixel, a project or a DelivrDSP campaign over a time window, optionally narrowed by a filter or reduced to the distinct values of one field. Use it to size a window before you pull rows with the tier routes.

Counts only, and not billed. The response is a number, never event rows.

Scope. Name one of pixel_id or project_id (source=pixel, the default), or campaign_id with source=dsp. A project counts across all its pixels.

Window. start_ms and end_ms are required, and the maximum window depends on the query:

• A plain count: 168 hours.
• A count with filter or distinct: 75 hours.
• With include_cold=true: 92 days, for either kind.

A wider window returns 400.

Example. Count the page views on one pixel over one day:

GET /api/v2/event_counts?pixel_id=px_123&start_ms=1792022400000&end_ms=1792108800000&filter=event_type:eq:page_view