Diagnose before changing anything. Most openalgo-charts bugs are one of a small set of known causes, and guessing at a fix usually adds a second bug on top of the first.
Step 1 - ground yourself in the actual install
node -p "require('./node_modules/openalgo-charts/package.json').version" 2>/dev/null || echo "not a consumer app"
rg -n "from 'openalgo-charts" src app --glob '!node_modules'
You need the version and the exact set of tier imports before you can reason about anything. Never diagnose from memory of the API.
Step 2 - match the symptom
| Symptom | First suspect | Confirm |
|---|---|---|
| Nothing renders, no error | container has zero height | inspect the element's computed height |
Nothing renders after setData |
data is empty, or times are not numbers | log series.getData().length and the first item |
| Bars bunched at the far left or right | time is in milliseconds |
a value above 1e12 is milliseconds |
| Bars overlap or a candle draws twice | two bars share a time | times must be unique and ascending per series |
| Axis and crosshair show the wrong hours | the chart is on its default zone, Asia/Kolkata |
chart.timezone(); set timezone or call setTimezone |
| VWAP restarts mid-afternoon, or a pivot frame spans two sessions | the chart's zone is not the instrument's | chart.timezone(); a timeFormatter relabels but does not move the calendar |
unknown series type "kagi" |
transform tier not imported | rg "openalgo-charts/transform" |
addIndicator throws |
indicators tier not imported | rg "openalgo-charts/indicators" |
| A tier is imported but its feature is missing | deep import created a second registry | check for any path containing /dist/ or /src/ in an import |
| Indicator plots misaligned with price | indicator on a different data set, or bar times differ | compare the first and last bar times |
| Series fills or is squashed into part of the pane | price-scale margins | margins are fractions of pane height, not data span |
| A volume overlay swallows the price series | overlay scale margins | priceScaleId: '' plus marginTop |
| Drawings drift after zoom or a session gap | anchors stored in pixels | anchors must be { time, price } |
| A drawing shortcut does nothing | the library installs no key listener | the host must call matchDrawingShortcut |
| Chart does not resize | no ResizeObserver, or container is not measurable |
call chart.applySize(w, h) manually |
| Custom primitive is blurry or offset | media px not multiplied by dpr |
inspect the draw implementation |
| Live ticks never appear | subscription filter, or the builder was never seeded | log inside the tick handler before the builder |
| Live candle duplicates the last history bar | builder started unseeded | pass seedFrom: lastHistoryBar |
| Hidden-tab chart opens at the wrong zoom | old initial-size handling or an explicit host fit | 2.1.3 defers its first fit; inspect applySize, navigation.defaultVisibleBars and later host writes |
| Drawing preview disappears past the last candle, or a future freehand stroke is discarded | no hovered bar time in empty chart space | 2.1.5 maps the pointer through coordinateToTime; custom drawing hosts must provide it. Keep candle/tooltip time null where no bar exists |
| Plot drags stop vertical movement | explicit or saved horizontal preference, including a 2.1.3 layout | 2.1.4 defaults to 'both'; select Axes > Mouse drag > Time and price or set navigation.mousePan: 'both', preserving other preferences |
| Time-axis drag behaves differently on one page | stale copied or bundled runtime | left expands, right compresses; compare deployed bundle hashes and run the website navigation check |
| Replay suddenly reveals future bars | a host history/polling/reconnect writer bypasses replay | inspect every setData, update and prependData; see host integration |
| Old symbol data or resources return after closing | stale async continuation | verify generation, chart identity and disposed state after every await |
| Custom indicator intermittently missing on a split pane | registration marked ready before imports finish | await one shared pending registration promise |
| Chart snaps to the right edge on every update | setData called per tick |
use series.update(bar) |
| Viewport jumps when older history loads | re-fitting after prepend | prependData preserves the window; do not fitContent |
| A linked crosshair marks the wrong bar | a logical index was copied between charts | it lines up only while both charts hold identical bars; the sync must convert index to time and back |
| Linked charts show different periods after a pan | the same index copy, on the viewport | use the group, or followerRange, never setVisibleLogicalRange(other.getVisibleLogicalRange()) |
| A linked chart shows no crosshair at all | the instant is outside its coverage, or whenMissing: 'hide' |
group.crosshairIndex(chart) returns null; an instant past its first/last bar is refused by design |
| Symbol sync changes nothing | no onSymbol on the member, or the host never reports the change |
the engine has no instrument concept; check both halves |
| The last price is stale after switching symbols and back | a cache serving the forming bar | withBarCache never stores it; a hand-rolled cache usually does |
| Every load is cold out of hours | to is "now", past the entry's coverage |
cap to at the newest bar the session table says can exist |
UnknownIntervalError at subscribe time |
the interval code is not built in and was never registered | it is the intended behaviour, not a regression; registerInterval or fix the code |
| A monthly chart buckets into minutes | intervalToSeconds on a calendar code |
it throws now; use resolveInterval + bucketStartOf |
| A cut deleted nothing, or copied "into the void" | the async result was not awaited | await draw.cut() and check the boolean; read draw.clipboard().lastError() |
| Orders do not reach the broker | wrong layer | chart.trading is visualization only |
| Blank page in Next.js or SSR | chart created during server render | client-only component, create in an effect |
| Bare specifier fails in the browser | no bundler resolution | a path into dist/, an import map, or the script-tag files |
openalgo-charts.<tier>.standalone.js needs ... loaded before it |
a script-tag tier loaded before the base, or the widget before the draw tier | load the files in the order the message names, each once |
ERR_REQUIRE_ESM from require('openalgo-charts') |
a Node older than 20.19 or 22.12 cannot require ESM | await import('openalgo-charts'), or a newer Node |
pitfalls has the full verified list with the reason behind each. Host integration covers request ownership, replay and lifecycle checks.
Step 3 - read the console
The library throws named errors that identify the cause precisely rather than failing silently. Quote the exact message back to the user; it usually names the missing tier or the unknown id. Do not paraphrase it.
Step 4 - narrow with the smallest possible repro
Strip to a chart, one series, and static bars. If that renders, add back one thing at a time. This resolves ambiguous cases faster than reading more of the host's code.
import { createChart, generateBars } from 'openalgo-charts';
const chart = createChart(el);
chart.addSeries('candlestick').setData(generateBars(1700000000, 200, 3600));
chart.fitContent();
If generateBars renders and the user's data does not, the bug is in the data, not the chart.
Step 5 - report
State the cause, the evidence you have for it, and the one-line fix. If you could not reproduce or could not confirm the cause, say so rather than offering a speculative fix - a wrong fix to a charting bug is expensive to unwind.
Do not apply changes unless the user asked you to fix it, not just diagnose it.