Install

npm install @jimzandueta/tala

Charting requires an optional peer dependency:

npm install lightweight-charts

Quick Start

import { tala } from "@jimzandueta/tala";

const result = tala()
  .sma(14)
  .ema(12)
  .rsi(14)
  .macd(
    { fastPeriod: 12, slowPeriod: 26, signalLength: 9 },
    { includeSignal: true },
  )
  .run(history);

result[0].sma14; // most recent SMA-14
result[0].rsi14; // most recent RSI (0-100)
result[0].macd; // most recent MACD line

Cross/signal events with structured output:

const { history: enriched, signals } = tala()
  .sma(14)
  .macdCross()
  .rsiCross()
  .run(history, { structured: true });

signals.macdCross; // PriceHistoryEntry[] of cross events
signals.rsiCross; // PriceHistoryEntry[] of cross events

Charting

chart() is a terminal method that renders indicators on an interactive TradingView-style page. It works in two modes.

HTML mode

Writes a self-contained HTML file. Open it in any browser — no server needed.

await tala()
  .sma(14)
  .ema(26)
  .bb(20, 2)
  .macd()
  .rsi(14)
  .chart(history, { format: "html" });

• Full candlestick chart with all indicators
• Editable data table — tweak OHLCV values and see candles update live
• Per-pane hover tooltips, legend toggles, time-scale sync, PNG export

Server mode

Starts a local HTTP server that opens the browser automatically. Adds one thing HTML mode can't do: recalculate indicators after editing data.

await tala().sma(14).rsi(14).chart(history, { format: "server", port: 3000 });

Click Data → edit OHLCV values → click Recalculate → indicators re-run on the server and the chart refreshes with new SMA, RSI, MACD, etc.

Chart output includes:

• Candlestick chart with overlay indicators (SMA, EMA, Bollinger Bands, etc.)
• Oscillator panes grouped by compatible scales: 0–100 (RSI, ADX, Stoch), centered (MACD, Williams %R, Fisher), wide-range (CCI)
• Hover tooltips per pane with all indicator values
• Sidebar legend with toggle switches for each indicator
• Time-scale sync across all panes (toggle off for independent scrolling)
• PNG export via html2canvas
• Editable data modal with server-side recalculation

Options:

| Option | Type | Default | Description | | ---------- | -------------------- | -------------------------- | -------------------------------------------------------- | | format | 'html' \| 'server' | 'server' | 'html' writes a file, 'server' starts an HTTP server | | filePath | string | './demo/tala-chart.html' | Output path for HTML mode | | port | number | 7890 | Port for server mode | | title | string | 'tala chart' | Chart title |

Run demo/test-viz.ts to generate a sample chart, or demo/test-server.ts for the live server.

Indicators

| Category | Methods | | --------------- | -------------------------------------------------------------------------------------- | | Moving Averages | .sma() .ema() .wema() .alma() .trix() | | Momentum | .macd() .rsi() .cci() .adx() .fisher() .sts() .williamsR() .stochRSI() | | Volatility | .bb() .atr() | | Volume | .obv() .vwap() | | Price Levels | .pivotT() .fibRL() | | Cross Signals | .macdCross() .rsiCross() .cciCross() .almaCross() .fisherCross() |

Each indicator appends a key to PriceHistoryEntry (for example, .sma(14) writes entry.sma14).

License

MIT