Query message statistics

Sends, engagement and attributed revenue for merchant campaigns and flows, by send cohort: a click or order counts toward the hour its message was sent, bucketed in the property's timezone. Shopper sends (campaigns, Autos, Responses) are excluded from every row and total, so source_type: flow means merchant automations; a property with more than 1,000 Shopper campaigns and automations answers 503 service_unavailable rather than totals that include them. Attribution-dependent statistics come back once per attribution model the property has; data.attribution_models flags the default. Billing figures are not served here. A query is not a mutation and takes no Idempotency-Key. At most 3 dimensions and 500 rows; past 500, data.truncated is true and rows holds the first 500 — narrow with filter rather than paging. filter.message_id requires message in group_by (400 otherwise) and narrows rows only; totals cover the other filter clauses. Only these groupings are served in the property's timezone: none, source_type, interval alone, campaign or flow, and interval: day with campaign/flow and message; every other grouping is served in UTC days and says so in timezone_reason.