uplot-ws.js

let u;

const ws = new WebSocket("ws://127.0.0.1:6789/");

ws.onmessage = function(event) {
    const data = JSON.parse(event.data);

    switch (data.type) {                   
        case 'ohlc':
            let ohlc = [data.ts, data.o, data.h, data.l, data.c];

            if (u == null)
                u = new uPlot(opts, ohlc, document.body);
            else
                u.setData(ohlc);                  
            break;
        case 'askbid':                   
            break;
        default:
            console.error("unsupported event", data);
    }
};

got even closer now. i prefer this scheme because i would not know the range of y scale before hand.

as a result of the above i am getting the following plot
edit:

when i checked the console, i get these errors / warnings. first i thought this is some rendering issue. i realised late that i am using a flat data for ohlc and not a realistic one. thats why i did not get a proper image.