In the web UI subplots add ability to define static line graphs

[mrigi]

Describe your environment

• Operating system: Linux
• Python Version: 3.12.7
• CCXT version: 4.4.48
• Freqtrade Version: docker-2025.1-dev-aceb3ac7

Describe the enhancement

In the web UI subplots add ability to define static line graphs

Let's say you want to display scatter line with value of 20 at percentage subplot.
Right now you can add dataframe['20'] = 20 but it would me more logical to make it within config because this is purely decoration thing.
Maybe add "y" attribute? Something like this:
"20": { "y":"20", "color": "grey", "type":"scatter", "scatterSymbolSize":"2" }

And ofc this should not be displayed in overlay at all.

[xmatthias]

Transferring this to where it belongs (freqUI repo).

I'm not sure about the purpose of this if i'm honest - freqUI is designed to show indicators that are relevant to the bot - a line can be visually appealing - but usually also has meaning.

So if "20" is your value - it's most likely a "rsi cross" level.
Now this is a "magic" value, really - so the "20" could just as well be optimized to be 21 or 22 or 19.

by having this in the dataframe - the UI will automatically be updated with potential changes.
Having this configured in the UI however means that it's a static value - so while the UI shows a line at 20 - the strategy was using 19 instead, as recent tests show that value to work better.

[mrigi]

I hardly see developing a strategy without looking at charts and analyzing where indicators are when buy/sale happened. So it certainly has a meaning.

[xmatthias]

well as said - i don't disagree with this - but if "20" has a meaning, it should be in the dataframe and used from there - otherwise what you see can VERY quickly deviate from what the strategy is actually doing.