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Guidelines8 min read
Guidelines and recommendations for writing efficient, maintainable, and error-free kScript code.

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Code Structure

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Variable Declarations

Use the appropriate variable type for your data: Static variables for constants: Use for constants and values that never change across bars (e.g., periods, thresholds, multipliers). 
var period = 14;
var threshold = 70;
var multiplier = 2.0;
Regular variables for dynamic values: Use for dynamic values that change per bar but don’t need historical access. 
var signal = close > open;
var colorIndex = rsiValue > 70 ? 0 : 1;
Timeseries for historical data: Use only when absolutely necessary as they consume more memory. Declare as timeseries when you need to:
  • Store data source outputs: timeseries price_data = ohlcv(...)
  • Access past values at previous candle indices: sma_values[5]
// Only use timeseries when you need historical access
timeseries ohlcvData = ohlcv(symbol=currentSymbol, exchange=currentExchange);

// Indicator results should be var unless you need history
var currentRSI = rsi(source=ohlcvData.close, period=14);

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Technical Indicators

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Explicit Parameters

Always specify parameters explicitly for clarity. This makes your code more readable and maintainable. 
// Good - explicit parameters
var rsiValue = rsi(source=ohlcvData.close, period=14);

// Avoid - positional only (harder to read)
var rsiValue = rsi(ohlcvData.close, 14);

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Historical Data Access

Use bracket notation to access historical values safely: 
var currentClose = ohlcvData.close[0];   // Current bar
var previousClose = ohlcvData.close[1];  // Previous bar
var change = currentClose - previousClose;

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Plotting & Visualization

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Descriptive Plots

Use meaningful colors and widths to make your plots easy to distinguish: 
// Good - clear visual hierarchy
plotLine(value=fastMA, width=2, colors=["green"], label=["Fast MA"], desc=["10-period EMA"]);
plotLine(value=slowMA, width=3, colors=["red"], label=["Slow MA"], desc=["50-period EMA"]);

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Choose Appropriate Plot Types

Select the right plot function for your data type:
FunctionUse Case
plotLine()Continuous lines (MAs, RSI)
plotBar()Histogram data (volume, MACD)
plotCandle()OHLC data
plotShape()Discrete signals

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Debugging

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Use printTimeSeries for Timeseries Objects

Always use printTimeSeries() for timeseries objects instead of print(). The print() function only outputs the first value, while printTimeSeries() displays the complete structure. 
timeseries ohlcvData = ohlcv(symbol=currentSymbol, exchange=currentExchange);

// Good - shows full structure
printTimeSeries(ohlcvData);

// Limited - only shows first value
print(ohlcvData);

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Error Prevention

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Null Checking

Always check for invalid data before performing calculations: 
var safeValue = isNaN(calculation) ? 0 : calculation;

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Division by Zero

Protect against division by zero errors: 
var result = denominator != 0 ? numerator / denominator : 0;

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Array Bounds

Be careful when accessing historical data to avoid index errors: 
// Check if enough history exists
if (barIndex >= lookbackPeriod) {
  var historicalValue = data[lookbackPeriod];
}

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Performance Optimization

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Avoid Redundant Calculations

Store frequently used calculations in variables instead of recalculating: 
// Good - calculate once
var closePrice = ohlcvData.close[0];
var signal1 = closePrice > threshold1;
var signal2 = closePrice > threshold2;

// Avoid - redundant access
var signal1 = ohlcvData.close[0] > threshold1;
var signal2 = ohlcvData.close[0] > threshold2;

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Use Static Variables

For values that don’t change between bars, declare them once at the start: 
// Constants declared at start
var period = 14;
var overbought = 70;
var oversold = 30;

// Used throughout script
var rsiValue = rsi(source=ohlcvData.close, period=period);

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Limit Timeseries Creation

Only create timeseries when you actually need historical access. Regular variables are more memory-efficient: 
// Good - use var for current bar values
var currentRSI = rsi(source=ohlcvData.close, period=14);

// Only use timeseries if you need history
timeseries rsiHistory = rsi(source=ohlcvData.close, period=14);
var previousRSI = rsiHistory[1];  // Now you can access history