Script SDK Reference

Complete API reference for @chartlabs/script-sdk.

Script Base Class

Every indicator extends the Script class and implements calculate().

import { Script, input, plot, color } from '@chartlabs/script-sdk';

export default class MyIndicator extends Script {
  length = input.number('Period', 14, { min: 1, max: 200 });
  calculate() {
    plot('Value', this.sma('close', this.length), { color: color.blue });
  }
}

OHLCV Data (Current Bar)

Property	Type	Description
this.open	number	Open price of the current bar
this.high	number	High price
this.low	number	Low price
this.close	number	Close price
this.volume	number	Volume

Historical Access

Method	Returns	Description
this.get(series, barsAgo)	number	Get OHLCV value N bars ago. Series: 'open', 'high', 'low', 'close', 'volume'
this.getPlot(plotName, barsAgo)	number	Get a previously plotted value N bars ago. Essential for crossover detection

Bar Metadata

Property	Type	Description
this.bar	number	Current bar index (0 = first bar on chart)
this.isFirstBar	boolean	True when bar === 0
this.isLastBar	boolean	True on the most recent bar
this.barCount	number	Total number of bars on the chart

State Storage

Method	Description
this.setState(key, value)	Store a numeric value that persists across bars
this.getState(key, defaultValue?)	Retrieve stored value (returns defaultValue or 0 if not set)

TIP

Built-in functions (ema, rsi, macd, etc.) manage their own state internally. Only use setState/getState for your own custom running calculations.

Debug

Method	Description
this.log(...args)	Print to script console. Only outputs on the last bar to avoid flooding.

Built-in Functions

See Built-in Functions for the complete list with examples.

Moving Averages

sma, ema, wma, rma, smma, dema, tema, hma, vwma, linreg

Compound Indicators (return objects)

macd, bbands, stoch, supertrend

Single-Value Indicators

rsi, atr, cci, adx, mfi, obv, stdev

Range & Volatility

highest, lowest, sum, trueRange, change, roc, percentRank

Utility

crossOver, crossUnder, barsSince, valuewhen, rising, falling

Math

abs, max, min, round

Input Declarations

Inputs appear in the indicator settings dialog when users add your indicator to a chart.

Type	Syntax	Example
Number	input.number(label, default, {min?, max?, step?})	input.number('Period', 14, { min: 1, max: 200 })
Source	input.source(label, default?)	input.source('Source', 'close')
Boolean	input.boolean(label, default?)	input.boolean('Show MA', true)
Color	input.color(label, default?)	input.color('Line Color', '#3b82f6')
String	input.string(label, default?, {options?})	input.string('Mode', 'fast', { options: ['fast', 'slow'] })

Source options: 'close', 'open', 'high', 'low', 'volume', 'hl2', 'hlc3', 'ohlc4'

Plot Functions

See Plot Types Reference for detailed examples of each plot type.

Function	Description
plot(name, value, opts?)	Line plot
plotHistogram(name, value, opts?)	Histogram bar
plotColor(name, value, colors[], colorIndex, opts?)	Line with dynamic per-bar color
hline(name, level, opts?)	Static horizontal reference line
plotShape(name, condition, opts?)	Shape marker (triangle, circle, cross, diamond)
plotArrow(name, condition, opts?)	Directional arrow marker
plotArea(plot1, plot2, opts?)	Fill area between two plots
bgcolor(color, opts?)	Background color for current bar
barcolor(color)	Bar color for current bar

Plot Options

plot(): { color?: string, width?: number, style?: 'solid'|'dashed'|'dotted', overlay?: boolean }

plotHistogram(): { color?: string, baseValue?: number }

plotColor(): colors[] = array of color strings, colorIndex = which color this bar

plotShape(): { shape?: 'triangleup'|'triangledown'|'circle'|'cross'|'diamond', location?: 'abovebar'|'belowbar', color?: string, size?: 'tiny'|'small'|'normal'|'large', text?: string }

Color Constants

Color	Hex		Color	Hex
color.red	#ef4444		color.green	#22c55e
color.blue	#3b82f6		color.yellow	#eab308
color.orange	#f97316		color.purple	#a855f7
color.cyan	#06b6d4		color.magenta	#ec4899
color.lime	#84cc16		color.pink	#f472b6
color.teal	#14b8a6		color.gray	#6b7280
color.silver	#9ca3af		color.gold	#d97706
color.navy	#1e3a5f		color.maroon	#7f1d1d
color.aqua	#67e8f9		color.olive	#65a30d
color.white	#ffffff		color.black	#000000

You can also use any hex string: '#ff6600', 'rgba(34,197,94,0.15)'

Strategy Class

Strategies extend Strategy instead of Script and gain position management and order execution.

import { Script, Strategy, input, plot, plotShape, color } from '@chartlabs/script-sdk';

export default class MyStrategy extends Strategy {
  calculate() {
    // Access position state
    this.position.isLong   // boolean
    this.position.isShort  // boolean
    this.position.isFlat   // boolean
    this.position.size     // number
    this.position.entryPrice // number

    // Execute orders
    this.strategy.entry('Buy', 'long', { qty: 1 });
    this.strategy.exit('Sell', 'long');
    this.strategy.close('Close All');
  }
}

See Strategy Guide for complete strategy documentation.

Overlay vs Sub-pane

• Sub-pane (default): Indicators with different value ranges than price — RSI (0-100), MACD, histograms
• Overlay: Set overlay: true on any plot to draw on the price chart — moving averages, bands, channels