Indicators

The indicator node runs any of 116 technical indicators from the openalgo.ta library over a symbol's history, server-side.

Basic use

{ "id": "r", "type": "indicator", "position": { "x": 0, "y": 100 },
  "data": {
    "symbol": "RELIANCE", "exchange": "NSE",
    "interval": "D", "source": "api",
    "indicatorName": "rsi",
    "params": "{\"period\": 14}",
    "lookbackBars": 100,
    "tailBars": 5,
    "offsetBars": 0,
    "outputVariable": "rsi"
  } }

Field	Meaning
indicatorName	Function name, lowercase (rsi, sma, supertrend, macd, …)
params	JSON object of the indicator's own arguments, as a string
lookbackBars	How much history to compute over (capped at 200)
tailBars	Length of the returned series array
offsetBars	Which bar at_offset should read (0 = latest closed)
sourceSeries	Optional — compute over another series instead of fetching
sourceField	Optional — which field to read from each sourceSeries row

Reading the result

{{rsi.latest.value}}      value on the most recent closed bar
{{rsi.previous.value}}    value one bar earlier
{{rsi.at_offset.value}}   value offsetBars back
{{rsi.series}}            array of the last tailBars values
{{rsi.series[0].value}}   oldest value in that array
{{rsi.outputs}}           list of output names
{{rsi.bars_used}}         how many bars were actually computed over

Single-output indicators (rsi, sma, ema, atr, …) expose value.

Multi-output indicators expose out0, out1, out2, … in the library's own order:

Indicator	out0	out1	out2
macd	MACD line	signal	histogram
bbands	upper	middle	lower
supertrend	level	direction (-1 up, 1 down)	—
stochastic	%K	%D	—
adx	+DI	-DI	ADX
donchian	upper	middle	lower

So a supertrend value is {{st.latest.out0}} and its direction is {{st.latest.out1}}.

Historical indicator values

Use offsetBars to read a specific bar:

{ "data": { "indicatorName": "supertrend",
            "params": "{\"period\": 10, \"multiplier\": 3}",
            "offsetBars": 5, "outputVariable": "st" } }

{{st.at_offset.out0}} is the supertrend level five closed bars ago.

You can reverse-index series instead, but prefer at_offset: series[0]'s meaning depends on tailBars, so raising tailBars from 6 to 10 silently changes which bar series[0] refers to. at_offset is unambiguous.

Nesting indicators

Set sourceSeries to another indicator's series to compute an indicator of an indicator — for example a 9-period SMA of RSI:

{ "id": "smoothed", "type": "indicator", "position": { "x": 300, "y": 100 },
  "data": { "indicatorName": "sma", "params": "{\"period\": 9}",
            "sourceSeries": "{{rsi.series}}", "tailBars": 5,
            "outputVariable": "rsiSma" } }

Give the upstream node a large enough tailBars to feed the nested window — a 9-period SMA needs at least 9 upstream values.

Only single-series indicators can be nested (sma, ema, rsi, wma, stdev, highest, lowest, …). Anything needing independent high/low/close inputs (atr, supertrend, adx, …) cannot be reconstructed from one collapsed output series and returns a clear error.

sourceSeries also accepts a raw history array — {{h.data}} uses each row's close. Override with sourceField to use high, low, or a specific out1.

Crossovers

crossover, crossunder, and cross are not available as an indicator node: they need two independent series, and this node reads one symbol. Build a crossover from two indicator nodes plus an andGate — see Tutorial 3.

correlation and beta are excluded for the same reason (they compare two symbols).

The complete exclusion list

openalgo.ta ships more functions than the indicator node exposes. Eight need a second series, and one is unsupported, leaving the 116 you can use:

Excluded	Why	What to do instead
crossover, crossunder, cross	Compare two series	Two indicator nodes plus an andGate — Tutorial 3
correlation, beta	Compare two symbols	Not available in Flow; use the Python Strategy Host
exrem, flip, valuewhen	Need a second boolean series, and carry state across bars	Restructure as a stateless condition, or use the Python Strategy Host
median_bands	Not supported	—

Everything else in the library works as an indicator node.

Available indicators

Category	Functions
Trend	sma, ema, wma, dema, tema, hma, vwma, alma, kama, zlema, t3, frama, trima, mcginley, vidya, alligator, ma_envelopes, supertrend, ichimoku, ckstop
Momentum	rsi, macd, stochastic, stochf, stochrsi, cci, williams_r, bop, elderray, fisher, crsi, cmo, trix, mom, apo, ppo, po, dpo
Volatility	atr, natr, true_range, bbands, bbpercent, bbwidth, keltner, donchian, chaikin, rvi, ultimate_oscillator, uo_oscillator, massindex, chandelier_exit, hv, ulcerindex, starc
Volume	obv, obv_smoothed, vwap, mfi, adl, cmf, emv, force_index, nvi, nvi_with_ema, pvi, pvi_with_signal, volosc, vroc, kvo, pvt, rvol
Oscillators	roc, rocp, rocr, rocr100, awesome_oscillator, accelerator_oscillator, aroon_oscillator, cho, chop, kst, tsi, vi, stc, gator_oscillator, coppock
Statistical	linreg, linregangle, linregintercept, lrslope, variance, tsf, median, mode
Hybrid	adx, adxr, dx, dmi, minus_dm, plus_dm, aroon, pivot_points, psar, fractals, rwi
Price transform	avgprice, medprice, midprice, midpoint, typprice, wclprice
Utility	highest, lowest, change, stdev, rising, falling

Parameter names follow the openalgo.ta signatures — {"period": 14} for most, {"fast_period": 12, "slow_period": 26, "signal_period": 9} for MACD, {"period": 10, "multiplier": 3} for Supertrend. Required parameters get sensible defaults if you omit them.