Is there a TradingView indicator that detects Strat combos like 2-1-2 and 3-1-2?

Yes. TheStrat Suite is a free, open-source TheStrat indicator for TradingView that detects 2-1-2 and 3-1-2 inside reversals and continuations, 2-2 reversals and continuations, 3-2 expansions, outside bars and Failed 2s on up to six timeframes at once, draws the trigger, targets and stop for each, and can alert when one goes in force.

Can I get an alert when a 2-1-2 triggers?

Yes. Turn on the signal family (Inside Reversals or Inside Continuations), then create one TradingView alert on the indicator with the condition 'Any alert() function call'. The message names the timeframe and the combo, for example '1H 2d-1-2u HAM 🟢'. Alerts are switched per family, not per exact combo string.

Guide

Strat combos the Suite detects

TheStrat Suite is a free, open-source TheStrat indicator for TradingView that detects Strat combos like 2-1-2, 3-1-2 and 2-2 reversals, marks Failed 2s, and draws the entry, targets and stop for each one, on up to six timeframes from one chart. This page lists every combo it detects, the rule behind each, and how to get an alert when one triggers.

TheStrat Suite on an hourly SPY chart: a 2-2 up reversal with the entry, magnitude target, exhaustion level and stop drawn automatically — *A 2-2 up reversal on hourly SPY. The Suite drew the trigger, the magnitude target, the exhaustion level and the stop on its own.*

How every candle is classified

Each candle gets a number from one question: what did it do to the prior candle's range?

1 (inside): broke neither side of the prior candle.
2U / 2D (directional): broke exactly one side. 2u took the prior high, 2d the prior low.
3 (outside): broke both sides.

The Suite writes these in lowercase (2u, 2d), the same thing many traders write as 2U and 2D. It classifies every candle on each of your six timeframes and shows the result in the data table, in the combo labels on the chart, and, if you turn on Bar Coloring, in the candle colors themselves. A combo is the sequence of those numbers, oldest first: in 2d-1-2u the last token is the candle that is trading now. The full notation, including the edge cases, is in Bar Types & Notation.

Every combo, with its rule

C2 is two candles back, C1 the last closed candle, CC the current one. A combo goes in force when CC trades through the trigger, which is C1's high for a bull setup and C1's low for a bear setup.

Combo	Examples	Rule	Default
2-1-2 reversal	`2d-1-2u`, `2u-1-2d`	`C1` is inside; `CC` breaks it against `C2`'s direction.	On
3-1-2 reversal	`3-1-2u`, `3-1-2d`	Same as 2-1-2, with an outside bar as `C2`. Reversal when `CC` breaks against the way the 3 closed.	On
2-1-2 continuation	`2u-1-2u`, `2d-1-2d`	`C1` is inside; `CC` breaks it in `C2`'s direction.	On
3-1-2 continuation	`3-1-2u`, `3-1-2d`	Same, with the break in the direction the 3 closed.	On
1-1-2	`1-1-2u`	Stacked inside bars, then a break. Read as a reversal or continuation from `C2`'s close; a `C2` that closed flat counts as a reversal.	On
2-2 reversal	`2d-2u`, `2u-2d`	`CC` breaks the opposite side of a directional `C1`, with no inside bar between.	On
Failed 2 into 2-2	`F2d-2u`, `F2u-2d`	A 2-2 reversal where `C1` was itself a Failed 2. Optional F2 filter on 2-2 reversals.	Off (filter)
2-2 continuation	`2u-2u`, `2d-2d`	`CC` breaks `C1` in the same direction. Noisy on its own, so it ships off.	Off
3-2 expansion	`3-2u`, `3-2d`	`C1` was an outside bar; `CC` commits to one side.	Off
Outside bar	`3u`, `3d`	`CC` itself takes both sides of `C1`. Direction is close against open.	Off
Failed 2 (range reclaim)	`F2u`, `F2d`	`CC` breaks one side of `C1`, then comes back inside. `F2u` failed the upside and is bearish; `F2d` failed the downside and is bullish.	Detected always; signal off

Every family can be filtered further: HAM/SHO requires C1 to be a hammer or shooter, and FTFC requires every timeframe you monitor to agree on direction (see Full Timeframe Continuity). A combo that has not triggered yet carries a *, as in *2d-1-2u.

What is not its own setting. A 3-2-2 has no separate toggle: its last two candles trigger as a 2-2 reversal, and the label shows the 2-2. Hammers and shooters are filters and label suffixes (HAM, SHO), not stand-alone signals.

What it draws for each combo

Trigger: C1's high or low as the entry line. Inside-bar setups draw both sides until one breaks. Bull lines turn green and bear lines turn red when in force.
Targets: the magnitude target (usually C2's high or low) and an exhaustion level beyond it.
Stop: optional, on the other side of the trigger, with break-even once a target is hit.
Take Action Window: a box over the higher-timeframe candle's lifetime, the window in which to look for lower-timeframe entries.

Details: Signals and Targets & Stops.

How to alert on a combo

Turn on the families you want under Signals (for example Inside Reversals for 2-1-2 and 3-1-2 reversals). Families that are off cannot alert.
Optionally, under Alerts - Detailed, choose which timeframes feed the alert and add the trigger, MAG, EXH and STOP prices and the FTFC state to the message.
In TradingView, create an alert on TheStrat Suite with the condition Any alert() function call. It fires once when a combo goes in force, not on every bar after.

A message looks like this:

1H 2d-1-2u HAM 🟢 | @ 542.10 MAG 545.30 EXH 548.20 STOP 538.10 | FTFC Up

🟢 is bull and 🔴 is bear. Alerts are switched by family, not by exact combo string, so if you only want 3-1-2s, filter on the text downstream (for example, a webhook receiver that keeps messages containing 3-1-2). Named conditions such as Signal In-Force (Bullish) exist for simpler routing. Webhooks and broker bridges are covered in Alerts & Automation.

Get it

TheStrat Suite is free and open source (MPL-2.0), by 345 Strategies, with more than 1,000 boosts on TradingView. Add it from TradingView or read the source on GitHub.