Scripting v2

MMT scripts are evaluated against historical and realtime market data, then emit plots and entities to the chart.

All v2 scripts must start with the version directive:

//@version=2

Quick Example

//@version=2
indicator("SMA Crossover", true)

const fastLen = input.int("Fast Length", 9, { min: 1 })
const slowLen = input.int("Slow Length", 21, { min: 1 })
const candles = subscribe(data.OHLCV)

function onBar(index) {
    const fast = ta.sma(candles.close(), fastLen)
    const slow = ta.sma(candles.close(), slowLen)

    const a = plot("Fast SMA", fast, { color: color.blue, width: 2 })
    const b = plot("Slow SMA", slow, { color: color.red, width: 2 })
    fill(a, b, { color: color.transp(color.blue, 85) })
}

Script Behavior

• Top-level code runs once when the script loads or changes
• onBar(index) runs for history warmup and realtime updates
• Built-in functions inside ta.*, math.*, str.*, and color.* are available in every script
• Higher-timeframe access is done with subscribe(..., { timeframe }), and higher-timeframe derived values should use subscription.calc(...)
• New plot labels may be blocked after history warmup, so declare labels early

API Map

• Execution Model
• Inputs
• Alerts
• Data Sources
• Examples
• Plotting
• Entities
• Globals
• Technical Analysis
• Math
• Strings
• Colors
• Timeframes
• Data
• Drawing
• Context
• v1 to v2 Migration

Key Limits

• Inputs: 256
• Subscriptions: 30
• Plot series labels: 64
• Plot commands per bar: 64
• Fill pairs per bar: 16
• Alert definitions: 32
• Alert fields per definition: 32
• Entities: 2000 each for Line, Box, Label, Marker, Arrow
• History retention, Free: 10,000 bars for non-BOOK sources, 5,000 for BOOK
• History retention, Pro: 20,000 bars for non-BOOK sources, 10,000 for BOOK

For LLMs

Fetch docs.mmt.gg/scripting/llms.txt for a page index, then pull individual pages as needed via /llms.mdx/{slug} (for example /llms.mdx/scripting/inputs).