Data API

The Data API is GA4's programmatic endpoint for pulling report data, metrics, and dimensions out of a property with code instead of the web interface.

You call it with a request that names the dimensions, metrics, date range, and filters you want, and it returns the same aggregated numbers the reports show, as structured data. It is what sits behind custom dashboards, automated exports into a spreadsheet, and any tool that needs GA4 figures without a person opening the reports.

Suppose leadership wants sessions and conversions by channel emailed every Monday. Instead of exporting by hand, you write a small script that calls the Data API for last week's numbers, drops them into a sheet, and sends it. The report builds itself while you sleep.

The API answers with the same sampling and thresholding as the interface. On large properties it can sample high-cardinality queries or withhold rows to protect identity, so the totals may not tie out to the raw BigQuery export exactly.

It automates the reports, not the raw data.