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Core Concept5 min read
Understanding kScript’s type system and the fundamental data types available for building trading algorithms.

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Primitive Data Types

The fundamental data types that form the building blocks of kScript. These are the basic values you’ll work with in your trading algorithms.

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number

Represents numerical values including integers and floating-point numbers. Used for prices, volumes, calculations, and mathematical operations. 
var price = 45000.50;
var volume = 1000;

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string

Text data used for labels, symbols, exchange names, and configuration values. Essential for identifying assets and displaying information. 
var symbol = "BTCUSDT";
var exchange = "BINANCE";

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boolean

True/false values used for conditional logic, flags, and decision making. Critical for implementing trading conditions and control flow. 
var isUptrend = true;
var showSignals = false;

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na

Represents “not a number” or missing values. When used in plots, those data points won’t be rendered, creating gaps in the visualization. Perfect for conditional indicators. 
plotLine(value=(condition ? value : na), width=2, colors=["red"], label=["Conditional"], desc=["Conditional Value"])

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Core kScript Types

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TimeSeries

The fundamental data structure for time-aligned market data. All price data and indicators are TimeSeries. This is how kScript handles historical data with indexing support. 
timeseries ohlcvData = ohlcv(currentSymbol, currentExchange);
timeseries rsiData = rsi(source=ohlcvData.close, period=14);
Key Features:
  • Historical Access: Use ts[0], ts[1], ts[n] for current and past values
  • Multi-field Data: OHLCV exposes .open, .high, .low, .close, .volume
  • Immutable: Values cannot be changed once set
  • Global Scope: Must be declared at the top level

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Input & Configuration Types

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select

Dropdown selection type for input parameters with predefined choices. Used with input() function to create user-friendly dropdown menus. 
var plotType = input(name="mode", type="select", options=["Line", "Bar"], defaultValue="Bar", label="Plot Type")

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DataSource

String identifiers for different types of market data available in the platform. Used with source() function to specify what data to fetch.
IdentifierDescription
"ohlcv"Price and volume data
"funding_rate"Funding rates
"liquidations"Liquidation data

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Position

Determines where your indicator appears on the chart interface. Used in the define() function.
ValueDescription
"onchart"Plotted on the main price chart
"offchart"Plotted in a separate panel below

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Visual & Plotting Types

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color

Color values for chart visualization and plotting. Supports hex codes, named colors, and RGB values. 
var lineColor = "#FF6B35";
var fillColor = "#008080";
var colors = ["red", "green", "blue"];

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ShapeType

Defines the type of shape to render when using plotShape function for marking signals and annotations. 
plotShape(value=close, shape="circle", width=2, colors=["red"], fill=true, label=["Close"], desc=["Close Price Shape"]);

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Practical Examples

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Color Arrays for Multi-Line Plots

Use color arrays to style multiple data series with different colors: 
//@version=2

define(title="Multi-MA Indicator", position="onchart", axis=true);

timeseries trade = ohlcv(symbol=currentSymbol, exchange=currentExchange);

// Calculate multiple moving averages
timeseries sma20 = sma(source=trade.close, period=20);
timeseries sma50 = sma(source=trade.close, period=50);

// Use color arrays for different lines
var colors = ["#FF6B35", "#3B82F6", "#10B981"];

plotLine(value=sma20, width=2, colors=colors, colorIndex=0, label=["SMA 20"], desc=["20-period Simple Moving Average"]);
plotLine(value=sma50, width=2, colors=colors, colorIndex=1, label=["SMA 50"], desc=["50-period Simple Moving Average"]);

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Conditional Plotting with na

Combine boolean conditions with na to create indicators that only show when specific conditions are met: 
//@version=2

define(title="50BTC Limit", position="offchart", axis=true);

timeseries trade = ohlcv(symbol=currentSymbol, exchange=currentExchange);

var limit = 50;

// Only plot when volume exceeds limit, otherwise use na
plotLine(value=(trade.volume > limit ? trade.close : na), width=2, colors=["red"], label=["Volume Filtered"], desc=["Volume Filtered Price"])

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Type Conversion & Indexing

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TimeSeries Indexing

Access specific price components from OHLCV data:
IndexField
0Timestamp
1Open
2High
3Low
4Close
5Volume

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Creating TimeSeries

Extract specific data from multi-dimensional TimeSeries: 
timeseries trade = ohlcv(currentSymbol, currentExchange);

// Extract close prices
var close = trade.close;

// Extract volume
var volume = trade.volume;

// Using ShapeType for plotting
plotShape(value=close, shape="circle", width=2, colors=["red"], fill=true, label=["Close"], desc=["Close Price Shape"]);

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Best Practices

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Use Descriptive Names

Choose clear variable names that indicate the data type and purpose: 
timeseries trade = ohlcv(currentSymbol, currentExchange);
var close = trade.close;

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Use Appropriate Types

Choose the right data type for your use case to ensure type safety: 
var showMA = input("showMA", "boolean", true);