Hi Team,

Looking at the following documentation:

https://developers.klaviyo.com/en/docs/using_the_query_metric_aggregates_endpoint#unique-opens-unique_opens-for-all-sent-messages

The  Metric Aggregates API is used with a GROUP BY `$message`. According to the documentation:

> The results will be grouped by message ID (using "by": ["$message"] as an attribute).

However, when doing some local tests using my own data, it seems to be that the campaign ID is returned, and not the message ID. This means, either the document is wrong, or the API response is wrong.

Would it be possible to get some clarity on this? Knowing which ID is being returned is crucial in our data pipelines.

All the best,

Louis