Custom Scripts

Custom Scripts let you build your own indicators on the trade chart and the trade journal chart. You write a short script, in a language modeled on TradingView’s Pine Script, and the chart draws the result on every candle. There are two Custom Script indicators:

Indicator	Where it draws
MFP Custom Script	Its own pane below the price chart, like RSI or MACD.
MFP Custom Script Overlay	On top of the candles, like a moving average.

Custom Scripts are rolling out gradually. If you don’t find them in the Indicators dialog, they aren’t available on your account yet.

Add a script

Open the chart and select Indicators.
Search for MFP and choose MFP Custom Script or MFP Custom Script Overlay.
Open the indicator’s settings from its row in the chart legend.
On the Inputs tab, replace the text in the Script box with your script and select Ok.

Your script is saved with your chart layout, so it comes back when you reload the page. You can add each indicator more than once to run several scripts side by side. Scripts run only in your browser, on the candles already loaded on your chart. A script can read prices and draw on the chart. It can’t place orders, change settings, or read anything else about your account, so a script someone shares with you can’t act on your behalf.

Fix errors

If a script has a mistake, the indicator draws nothing and a notice appears at the bottom of the chart. The notice gives the line and column of the problem and, where it can, a suggestion:

Line 2, column 6: Unknown name "clsoe". Did you mean "close"?

The notice clears as soon as the script is valid. You can dismiss it with the close button; it stays hidden until a different error appears or you reload the page.

Write a script

A script is a list of statements, one per line. You can also separate statements with a semicolon. Text after // is a comment.

// Two moving averages
fast = ema(close, 9)
slow = ema(close, 21)
plot(fast, "Fast", color=color.blue)
plot(slow, "Slow", color=color.orange)

Names. fast = ema(close, 9) gives a value a name you can reuse on later lines. Each name can be set once, and a name can’t reuse a built-in value such as close or na.
One-line scripts. A script that is a single expression, such as ema(close, 21), draws that expression as a line.
Long lines. A line continues onto the next one when the next line is indented, when it starts with an operator such as + or ?, or when the line ends with an operator, a comma, or an open bracket.
History. Add [n] to read a value from n candles ago: close[1] is the previous close, and fast[5] is fast five candles back.
Missing values. na means “no value”. Math with na gives na, and a line isn’t drawn where its value is na. Early candles often have no value because a moving average needs a full window first.

Operators

Operator	Meaning
`+` `-` `*` `/` `%`	Arithmetic. Dividing by zero gives `na`.
`>` `<` `>=` `<=` `==` `!=`	Comparisons. They give `1` for true and `0` for false.
`and` `or` `not`	Logic. Any nonzero value counts as true.
`condition ? a : b`	`a` when the condition is true, otherwise `b`.

&& and ! work like and and not, and a double vertical bar works like or. true and false are the same as 1 and 0.

Draw lines

plot(value, title, color, linewidth, style) draws a line. Only the value is required; the other arguments can be passed in order or by name.

plot(rsi(close, 14), "RSI", color=color.purple, linewidth=2)
hline(70, "Overbought", color=color.gray)
hline(30, "Oversold", color=color.gray)

hline(price, title, color, linestyle, linewidth) draws a horizontal level. It is dashed unless you set linestyle.

Argument	Values
`style`	`plot.style_line`, `plot.style_linebr`, `plot.style_stepline`, `plot.style_histogram`, `plot.style_columns`, `plot.style_area`, `plot.style_areabr`, `plot.style_circles`, `plot.style_cross`
`linewidth`	A whole number from 1 to 4.
`linestyle`	`hline.style_solid`, `hline.style_dotted`, `hline.style_dashed`

A script can draw up to 8 lines between plot and hline. In the indicator’s Style tab they appear in order as Plot 1 to Plot 8; titles are for your own reference and don’t rename those rows. The style and width you set in the script apply whenever you add the indicator or edit the script. Between edits you can still change them in the Style tab.

Colors

Colors come from your script, so the Style tab has no color pickers for Custom Scripts. A line with no color uses its slot’s default color.

Form	Example
Named color	`color.red`
Hex code	`#FF5252`, or `#FF525280` with transparency
Transparency (0 is solid, 100 is invisible)	`color.new(color.green, 80)`
Red, green, blue, and optional transparency	`color.rgb(255, 82, 82, 50)`
A blend between two colors	`color.from_gradient(rsi(close, 14), 30, 70, color.red, color.green)`

The named colors are color.aqua, color.black, color.blue, color.fuchsia, color.gray, color.green, color.lime, color.maroon, color.navy, color.olive, color.orange, color.purple, color.red, color.silver, color.teal, color.white, and color.yellow. A color can change from candle to candle:

hist = ema(close, 12) - ema(close, 26)
plot(hist, "Momentum", color = hist >= 0 ? color.green : color.red, style=plot.style_columns)

Older scripts that pass transp= alongside a color are also supported.

Mark candles

plotshape(condition, title, style, location, color) draws a marker on every candle where the condition is true. A script can have up to 4 markers.

fast = ema(close, 9)
slow = ema(close, 21)
plotshape(crossover(fast, slow), "Cross up", style=shape.triangleup, location=location.belowbar, color=color.green)
plotshape(crossunder(fast, slow), "Cross down", style=shape.triangledown, location=location.abovebar, color=color.red)

Argument	Values
`style`	`shape.triangleup`, `shape.triangledown`, `shape.arrowup`, `shape.arrowdown`, `shape.labelup`, `shape.labeldown`, `shape.circle`, `shape.square`, `shape.diamond`, `shape.flag`, `shape.cross`, `shape.xcross`
`location`	`location.abovebar`, `location.belowbar`, `location.top`, `location.bottom`, `location.absolute`

With location.absolute, the marker sits at the value you pass instead of at the candle, for example plotshape(high, location=location.absolute). In MFP Custom Script, which draws in its own pane, above-bar and below-bar markers are placed at the top and bottom of that pane.

Shade the background and candles

bgcolor(color) shades the chart background behind candles. barcolor(color) recolors the candles themselves. Pass na to leave a candle unchanged.

bgcolor(rsi(close, 14) > 70 ? color.new(color.red, 85) : na)
barcolor(volume > 2 * sma(volume, 20) ? color.yellow : na)

If a script calls either function more than once, later calls take priority wherever they give a color.

Add adjustable inputs

Inputs let you change a script’s numbers without editing the script.

length = input.int(20, "Length", minval=1)
source = input.source(close, "Source")
plot(sma(source, length))

The Inputs tab has fields Input 1 to Input 8. They match the script’s inputs in the order they appear: the first input call is Input 1, the second is Input 2, and so on. Leave a field blank to use the script’s default, or type a value to replace it. A value outside minval or maxval, or of the wrong kind, shows an error that names the input. Inputs can also appear directly inside a helper. For example, sma(input.source(close), input.int(20)) uses Input 1 for the source and Input 2 for the length. Each input call uses one field, including inside helpers such as vwma, cci, hma, and stoch.

Function	Accepts
`input.int(default, title, minval, maxval)`	A whole number.
`input.float(default, title, minval, maxval)`	Any number.
`input.bool(default, title)`	`true` or `false` (also `yes`, `no`, `on`, `off`, `1`, `0`).
`input.source(default, title)`	`open`, `high`, `low`, `close`, `volume`, `hl2`, `hlc3`, `ohlc4`, or `hlcc4`.
`input(default, title)`	Takes its kind from the default: a whole number, a decimal, `true`/`false`, or a source.

Built-in values

Name	Value
`open` `high` `low` `close` `volume`	The candle’s prices and volume.
`hl2` `hlc3` `ohlc4` `hlcc4`	Averages of the candle’s prices.
`tr`	True range, which counts a gap from the previous close.
`vwap`	Volume-weighted average price since 00:00 UTC.
`bar_index`	The candle’s position, starting at 0.
`math.pi` `math.e`	Math constants.

Built-in functions

Lengths and occurrences must be whole numbers known before the script runs: a number, an input, or a name set to one of those (for example len = input.int(14) or slow = len * 2). You can write functions with or without Pine’s ta. and math. prefixes, so ta.sma and sma are the same.

Group	Functions
Moving averages	`sma(src, len)`, `ema(src, len)`, `wma(src, len)`, `rma(src, len)`, `hma(src, len)`, `vwma(src, len)`, `vwap(src)`
Oscillators	`rsi(src, len)`, `stoch(src, high, low, len)`, `cci(src, len)`, `atr(len)`, `tr()`
Windows	`highest(src, len)`, `lowest(src, len)`, `sum(src, len)`, `stdev(src, len)`, `variance(src, len)`, `dev(src, len)`, `median(src, len)`
Change	`change(src, len)`, `mom(src, len)`, `roc(src, len)`, `cum(src)`
Signals	`crossover(a, b)`, `crossunder(a, b)`, `cross(a, b)`, `rising(src, len)`, `falling(src, len)`, `barssince(cond)`, `valuewhen(cond, src, occurrence)`
Missing values	`na(x)`, `nz(x, replacement)`, `iff(cond, a, b)`
Math	`abs`, `sqrt`, `exp`, `log`, `log10`, `pow`, `floor`, `ceil`, `round(x, decimals)`, `sign`, `min`, `max`, `avg`, `sin`, `cos`, `tan`, `asin`, `acos`, `atan`

Notes on specific functions:

highest(len) and lowest(len) with only a length use high and low.
change, mom, and roc compare against one candle back when you leave out the length.
stdev and variance measure the whole window (population), matching Pine.
valuewhen(cond, src, 0) is the value at the most recent candle where the condition was true; 1 is the one before that, up to 9.
min, max, and avg take 2 to 10 values.

Limits

Limit	Value
Script length	4,000 characters
Lines (`plot` and `hline`)	8
Markers (`plotshape`)	4
Inputs	8
History reference (`close[n]`)	5,000 candles
Length of any one function	5,000 candles
All function lengths in one script, added up	20,000 candles

The last limit keeps a script from slowing down your chart. A script over any limit shows an error instead of running.

Differences from Pine Script

Many simple Pine Script indicators paste in with little or no change, and headers such as //@version=5 and indicator(...) are accepted. These parts of Pine Script aren’t supported, and each shows an error explaining so:

if, for, while, and switch blocks. Use condition ? a : b.
var, reassigning with :=, and your own functions.
Lists, tuples such as [a, b] = ..., and text other than titles.
Data from other markets or timeframes (request.security).
Strategies, alerts, fill, plotchar, plotarrow, and drawing objects such as labels, lines, boxes, and tables.
offset= on plots, and input.string, input.color, and input.timeframe.

plotshape accepts text= and size=, but markers are drawn without text, at the chart’s standard size. alertcondition is accepted and has no effect.

Examples

MACD

fastLen = input.int(12, "Fast")
slowLen = input.int(26, "Slow")
macd = ema(close, fastLen) - ema(close, slowLen)
signal = ema(macd, 9)
hist = macd - signal
plot(hist, "Histogram", color = hist >= 0 ? color.green : color.red, style=plot.style_columns)
plot(macd, "MACD", color=color.blue)
plot(signal, "Signal", color=color.orange)
hline(0)

Use MFP Custom Script so it draws in its own pane.

Bollinger Bands with breakouts

len = input.int(20, "Length")
mult = input.float(2, "Width")
basis = sma(close, len)
band = mult * stdev(close, len)
plot(basis, "Basis", color=color.orange)
plot(basis + band, "Upper", color=color.teal)
plot(basis - band, "Lower", color=color.teal)
plotshape(crossover(close, basis + band), "Breakout", style=shape.triangleup, location=location.belowbar, color=color.lime)
bgcolor(close > basis + band ? color.new(color.green, 85) : na)

Use MFP Custom Script Overlay so it draws on the candles.

RSI with colored levels

r = rsi(close, 14)
plot(r, "RSI", color=color.from_gradient(r, 30, 70, color.red, color.green))
hline(70)
hline(30)
bgcolor(r > 70 or r < 30 ? color.new(color.gray, 85) : na)

Overview

Guides

Challenge Lifecycle

Settings

Add a script

Fix errors

Write a script

Operators

Draw lines

Colors

Mark candles

Shade the background and candles

Add adjustable inputs

Built-in values

Built-in functions

Limits

Differences from Pine Script

Examples

MACD

Bollinger Bands with breakouts

RSI with colored levels

​Add a script

​Fix errors

​Write a script

​Operators

​Draw lines

​Colors

​Mark candles

​Shade the background and candles

​Add adjustable inputs

​Built-in values

​Built-in functions

​Limits

​Differences from Pine Script

​Examples

​MACD

​Bollinger Bands with breakouts

​RSI with colored levels

Add a script

Fix errors

Write a script

Operators

Draw lines

Colors

Mark candles

Shade the background and candles

Add adjustable inputs

Built-in values

Built-in functions

Limits

Differences from Pine Script

Examples

MACD

Bollinger Bands with breakouts

RSI with colored levels