Settings & Export

Chart Settings

Click the settings icon in the toolbar to open the settings drawer. Changes apply immediately to the chart. On an existing trend, click Save in the drawer footer to persist them. On a trend you haven't saved yet, the drawer shows Done instead, and the settings are saved when you create the trend.

Sampling

Sampling controls how raw data points are aggregated when viewing large time ranges.

Window Period determines the time bucket size:

Auto: the system picks a window that fills the chart's width with data points, based on the visible range
Custom: choose a fixed window: Raw (no aggregation), 1s, 5s, 10s, 30s, 1m, 5m, 15m, or 1h

Aggregate Function reduces each window to a single value:

Auto: uses Mean
Custom: choose from Mean, Median, Last, First, Min, Max, or Sum

Fill Missing Values carries the last known value forward to fill gaps and produce a continuous line. Disabled in Raw mode.

Raw mode on large time ranges

Selecting Raw over days or weeks can result in very large data transfers and slow rendering. Use it for short, focused time windows.

Display

Setting	Range	Default
Show legend	On / Off	Off
Legend position	Top, Bottom, Left, Right	Top
Fill area under lines	On / Off	Off
Fill opacity	0 – 1.0	0.1
Line width	0.5 – 5.0	1
Point size	0 – 5.0 (0 hides points)	1.5
Line smoothing	0 (sharp) – 0.5 (smooth)	0.15
Show events	On / Off	On

Exporting Data

Click the export icon in the toolbar to open the export drawer. The same export can be run from a script with the Python API Client, including a size estimate before you commit to a large range.

Configuration

Date range: defaults to the chart's visible range, or check Export all data to export complete history
Tag selection: all plotted tags are included by default; uncheck any you don't need, or add tags that aren't in the trend
Mode: Raw exports every data point as stored; Resampled aggregates to regular intervals (1s–1h) with a chosen aggregate function
Format: CSV, JSON, or Parquet
Split into daily files: creates one file per calendar day, packaged as a ZIP

Formats

Format	Timestamps	Best for
CSV	Text, ISO 8601	Spreadsheets and anything that reads plain text
JSON	Text, ISO 8601	Scripts and integrations
Parquet	A real timestamp column	Analysis tools, which read it back typed rather than parsing text

Every tag you select gets a column, whether or not it has readings in the range. A tag with no data in the range appears with an empty column rather than being left out of the file.

Downloading

The download starts as soon as you confirm the export, and your browser saves it while it is still being produced. There is no waiting for a file to be built first and no second step to remember: it appears in your browser's downloads straight away and fills in as the data is read.

Because your browser owns the transfer, everything it normally does applies — pausing and resuming, and a destination you choose. Moving to another page or closing the export panel does not interrupt it.

While the export runs, the panel shows how much of the date range has been read. A large export can take several minutes, and the size is not known in advance, so your browser can only report the bytes it has received — the panel is what tells you how far through the data it is. It closes itself when the export finishes.

Nothing is left on the server

The export is produced as it is sent, so there is no copy kept afterwards, nothing to expire, and no record of it beyond the audit trail. Run the export again whenever you need it.

An interrupted export does not leave a partial file

If the connection drops or the data cannot be read part-way through, your browser reports the download as failed rather than keeping what arrived. A file that finishes downloading is a complete export.

Very large exports are still refused before they start — see Size Limits. The check runs when you confirm, so an export that grew past the limit while the panel was open is caught then rather than half-way through.

Permission

Exporting trend data requires the Can export trend data permission, which also covers the size estimate. On upgrade it is granted to every role that can already manage trends, so nobody loses access they had. See Roles & Permissions.

Size Limits

Koios estimates the export size before starting:

Threshold	Behavior
Under 200 MB	Proceeds normally
200 MB – 10 GB	Warning: may take a while
Over 10 GB	Blocked: narrow the date range or reduce tags

The server applies the 10 GB limit to every export, including requests made through the API or the Python client, and a refused export says how large it was estimated to be. The export panel applies the same limit before you start. The warning between 200 MB and 10 GB appears only in the export panel.

Because the export is sent as it is produced, its size is no longer limited by what has to fit anywhere — the ceiling is about how long one should reasonably run. What is limited instead is how many run at once: each one occupies part of the server while it produces data, so an export started while several others are already running is refused, and the panel says so rather than starting a download that fails.

A raw export's estimate counts the readings stored in the date range. If that count cannot be completed, the server refuses the export rather than start one of unknown size: try again, or narrow the date range.

What's Next

Trends: overview and chart navigation
Traces & Axes: add tags and configure multi-axis layouts

Traces & Axes Dashboard