Liveline

Real-time animated charts for React. Line, multi-series, and candlestick modes, canvas-rendered, 60fps, zero CSS imports.

Install

pnpm add liveline

Peer dependency: react >=18.

Quick Start

import { Liveline } from 'liveline'
import type { LivelinePoint } from 'liveline'

function Chart() {
  const [data, setData] = useState<LivelinePoint[]>([])
  const [value, setValue] = useState(0)

  // Feed data from WebSocket, polling, etc.
  // Each point: { time: unixSeconds, value: number }

  return (
    <div style={{ height: 300 }}>
      <Liveline data={data} value={value} color="#3b82f6" theme="dark" />
    </div>
  )
}

The component fills its parent container. Set a height on the parent. Pass data as a growing array of points and value as the latest number — Liveline handles smooth interpolation between updates.

Props

Data

Appearance

Features

Candlestick

When mode="candle", pass candles (committed OHLC bars) and liveCandle (the current bar, updated every tick). candleWidth sets the time bucket in seconds. The lineMode prop smoothly morphs between candle and line views — candle bodies collapse to close price, then the line extends outward. Provide lineData and lineValue (tick-level resolution) for a smooth density transition during the morph.

The onModeChange prop renders a built-in line/candle toggle next to the time window buttons.

Multi-series

Pass series instead of data/value to draw multiple lines sharing the same axes. Each series gets its own color, label, and endpoint dot. Toggle chips appear automatically when there are 2+ series — clicking one hides/shows that line with a smooth fade. The Y-axis range adjusts when series are hidden. Badge, momentum arrows, and fill are disabled in multi-series mode.

State

When loading flips to false with data present, the loading line morphs into the actual chart shape. In line mode, the fill, grid, and badge animate in. In candle mode, flat lines expand into full OHLC bodies while the morph line fades out. When data is empty and loading is false, a minimal "No data" empty state is shown.

Time

Crosshair

Orderbook

Advanced

Examples

Basic (line + badge)

<Liveline data={data} value={value} color="#3b82f6" theme="dark" />

Candlestick (minimal)

<Liveline
  mode="candle"
  data={ticks}
  value={latestTick}
  candles={candles}
  candleWidth={60}
  liveCandle={liveCandle}
  color="#f7931a"
  formatValue={(v) => `$${v.toLocaleString('en-US', { minimumFractionDigits: 2 })}`}
/>

Candlestick (line mode toggle + time windows)

<Liveline
  mode="candle"
  data={ticks}
  value={latestTick}
  candles={candles}
  candleWidth={60}
  liveCandle={liveCandle}
  lineMode={showLine}
  lineData={ticks}
  lineValue={latestTick}
  onModeChange={(mode) => setShowLine(mode === 'line')}
  color="#f7931a"
  formatValue={(v) => `$${v.toLocaleString('en-US', { minimumFractionDigits: 2 })}`}
  windows={[
    { label: '5m', secs: 300 },
    { label: '15m', secs: 900 },
    { label: '1h', secs: 3600 },
  ]}
/>

Crypto-style (momentum + degen + exaggerate)

<Liveline
  data={data}
  value={value}
  color="#f7931a"
  exaggerate
  degen
  showValue
  valueMomentumColor
  formatValue={(v) => `$${v.toLocaleString('en-US', { minimumFractionDigits: 2 })}`}
/>

Dashboard (showValue + windows + no badge)

<Liveline
  data={data}
  value={value}
  badge={false}
  showValue
  windows={[
    { label: '15s', secs: 15 },
    { label: '30s', secs: 30 },
    { label: '2m', secs: 120 },
    { label: '5m', secs: 300 },
  ]}
  onWindowChange={(secs) => console.log('window:', secs)}
/>

Multi-series (prediction market)

<Liveline
  data={[]}
  value={0}
  series={[
    { id: 'yes', data: yesData, value: yesValue, color: '#3b82f6', label: 'Yes' },
    { id: 'no', data: noData, value: noValue, color: '#ef4444', label: 'No' },
  ]}
  grid
  scrub
  pulse
  windowStyle="rounded"
  formatValue={(v) => v.toFixed(1) + '%'}
  onSeriesToggle={(id, visible) => console.log(id, visible)}
  windows={[
    { label: '10s', secs: 10 },
    { label: '30s', secs: 30 },
    { label: '1m', secs: 60 },
  ]}
/>

Loading + pause

<Liveline
  data={data}
  value={value}
  loading={isConnecting}
  paused={!isTabVisible}
/>

Orderbook (orderbook data + particles)

<Liveline
  data={data}
  value={value}
  color="#f7931a"
  orderbook={{ bids: [[100, 2], [99, 5]], asks: [[101, 3], [102, 4]] }}
  degen
  showValue
/>

How It Works

• Canvas rendering — single <canvas> element, no DOM nodes per data point
• requestAnimationFrame loop pauses when the tab is hidden
• Fritsch-Carlson monotone splines for smooth curves — no overshoots beyond local min/max
• Frame-rate-independent lerp on value, Y-axis range, badge color, and scrub opacity
• Candlestick rendering — OHLC bodies + wicks with bull/bear coloring, smooth live candle updates
• Line/candle morph — candle bodies collapse to close price, morph line extends center-out, coordinated alpha crossfade
• Multi-series — overlapping lines with per-series toggle, smooth alpha fade, and dynamic Y-axis range
• ResizeObserver tracks container size — no per-frame layout reads
• Theme derivation — full palette from one accent color + light/dark mode
• Binary search interpolation for hover value lookup

No CSS imports. No external dependencies beyond React.

License

© 2026 Benji Taylor

Licensed under MIT