Events

Nexus WFS API service returns raw or reduced (thinned out) timeseries events.

GET /wfs/?world={world_alias}&timeseries_id={timeseries_id}&token={web_api_token}

Parameters¶

Parameter	Mandatory	Meaning	Default value
`world`	Yes	Alias of world	-
`timeseries_id`	Yes	ID of timeseries in Nexus (retrieve through WFS `timeseries` feature type)	-
`view`	No	Type of view: `raw` or `reduced`	`raw`
`count`	No	Number of events to return	`100000`
`startindex`	No	Starting point for counting events (normally combined with `count`)	`0`
`sortby`	No	Sort property and order. Options: `timestamp d`, `timestamp a`, `value d`, `value a`	`timestamp d`
`range`	No	Applicable time domain, specified as `<start>/<end>`. Optional, but mandatory with `reduced` view.	-
`bucket_interval`	No	Only for the `reduced` view, bucket size for selecting min-max events, specified as for example `P1D`	-

Example

Request:

curl "https://nexus.stellaspark.com/api/v1/events/?world=sandbox&timeseries_id=13&count=3&token={web_api_token}"

Response:

timestamp,value
2025-10-21 00:00:00+00,16.1
2025-10-20 00:00:00+00,17.1
2025-10-19 00:00:00+00,14.2

Views¶

By default, the API returns all events of a timeseries (raw view). In addition, there is a reduced view, which returns a thinned out set of events. The data reduction algorithm divides the original raw timeseries in a certain amount of time buckets, defined by bucket_interval. For each time bucket two events are selected: the one with highest and with the lowest value. The left-most bucket is aligned with the left side of the range. So for example, for a range 2025-01-01T12:00:00Z/2025-01-02T12:00:00Z and bucket interval P2H, the initial bucket is between 2025-01-01T12:00:00Z and 2025-01-01T14:00:00Z.

If a bucket does not contain any events, logically nothing is returned for that bucket. In case the event with highest value within a bucket is the same as the event with lowest value, the event is returned only once (no duplicates).

Data chunking¶

Be aware that data volumes in Nexus can be huge. If you request all events of a timeseries at once, it may result in a truly large output file (especially for long series and/or high-frequency data). A core concept when you are working with the API is therefore to iterate over the content to gather everything that you are interested in.

This means that when you access data, you will retrieve it in parts. With the count parameter, you tell the API how much data you want to see at once. Together with the offset you can tell the API from where it should start counting in order to get the next chunk of data.

Example

Request:

curl "https://nexus.stellaspark.com/api/v1/events/?world=sandbox&timeseries_id=13&count=3&startindex=10&token={web_api_token}"

Response:

timestamp,value
2025-10-11 00:00:00+00,16.2
2025-10-10 00:00:00+00,17.5
2025-10-09 00:00:00+00,16.7

Note

By default, Nexus limits the number of returned rows to 100000.

Range¶

Optionally, a range can be specified as <start>/<end> to only select timeseries events in a limited window. The range may be defined as a static set of dates, timestamps, or relative offsets. Time range must be specified according to ISO 8601 standard. An ISO 8601 period string prefixed with a '+' or '-' indicates an offset relative from now, whereas an ISO 8601 period string without prefix indicates a relative offset from either the start or end of the range.

Example

Examples of valid ranges (unencoded):

- -P3D/+P1D (from 3 days ago until 1 day ahead)
- -P5M/P2M (from 5 months ago until 3 months ago)
- 2020-01-03T13:00/P3D (from January 3rd, 2020 until January 6th, 2020)
- 2020-01-03/2020-02-05 (static dates)

Bucket interval¶

The bucket_interval is specified as an ISO 8601 duration. Supported durations are weeks, days, hours, minutes and seconds. Durations don't need to be whole numbers, decimals are allowed.

Example

Examples of valid bucket intervals:

- P3D (3 days)
- PT6H (6 hours)
- P2DT6H30M (2 days, 6 hours and 30 minutes; this is equivalent to `P2DT6.5H`)