Using the Amplitude Dashboard REST API, I am attempting to get a count of all unique times a custom event was triggered with a filter of a custom event property. However I am unable to even get the simplest event segmentation to run, though all other endpoint hits (except Funnels which also use the e event parameter) are working as expected. In other words, my auth is working and I'm able to successfully get data from all the endpoints that don't require the e event parameter.
Here is an example of a constructed endpoint using event segmentation that is as simple as I believe it could possible be and which is failing with a 400 error.
https://amplitude.com/api/2/events/segmentation?e=\{"event_type":"_active"\}&start=20170401&end=20170402
While the call I want to do is ultimately more complex and involves a filter, I'm unable to just get this call which is one of the simplest event segmentation calls possible, considering the e, start, and end parameters are all required.
Try properly percent escaping the e parameter.
https://amplitude.com/api/2/events/segmentation?e=%7B%22event_type%22%3A%22_active%22%7D&start=20170401&end=20170402