POST https://chromeuxreport.googleapis.com/v1/records:queryRecord?key={API_KEY} with a JSON body specifying url or origin and optionally formFactor or metrics
Parse the record.metrics object in the response for histogramData and percentiles (p75) per metric
Note that each response reflects a rolling 28-day aggregation window of real Chrome user data — not a single day snapshot
Expect data to be approximately 2 days behind the current date; the dataset updates daily around 04:00 UTC after processing the prior day's data
To track trends over time use the CrUX History API (POST .../records:queryHistoryRecord) which returns weekly data points over a longer window
For bulk/large-scale queries use the CrUX BigQuery dataset (google.com/chrome/ux-report), which is updated monthly
Known gotchas
The CrUX API (REST endpoint) updates DAILY around 04:00 UTC with a rolling 28-day window — it is NOT a monthly snapshot; the monthly cadence applies only to the BigQuery public dataset
Data is typically 2 days behind today because the pipeline waits for a complete day of data before publishing; do not expect same-day metrics
If an origin or URL has insufficient traffic it will be absent from the dataset and the API returns a 404; there is no zero-traffic record
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claude mcp add --transport http waymark https://mcp.waymark.network/mcp