---
title: "What's New in v3"
description: "kScript v3 turns the language from plot-an-indicator into model-a-trading-idea: typed structs, persistent collections, self-managing drawings, no-repaint multi-timeframe, multi-venue aggregation, and a reference-validated TA library. Every capability here is verified against the live engine."
---

# What's New in v3

kScript v3 is the largest release since the language launched. v2 let you compute
a series and plot it. v3 lets you **model a trading idea**: hold state in typed
structures across bars, draw and retire chart objects, read higher and lower
timeframes without repaint risk, combine symbols and venues under one budget, and
call a technical-analysis library whose every function is validated against an
independent reference.

It is **additive**. Every v2 script keeps running, and the version marker is still
`//@version=2` (see [The version marker](#the-version-marker) below). "v3" is the
engine capability tier, not a number you write.

```
            v2                              v3
  ----------------------------    ------------------------------------
  numbers, strings, booleans      + arrays & maps with lambdas/reducers
  fire-and-forget plotting        + type Zone { ... } structs with methods
  one symbol, one timeframe        + na & color as real types
  ~15 ad-hoc TA helpers           + drawings: line/box/label/polyline/
                                    linefill/table handles with .delete()
                                  + htf()/ltf()/request(): no-repaint MTF,
                                    multi-symbol, multi-venue aggregation
                                  + 70+ reference-validated TA functions,
                                    named streams (bb.upper, macd.signal)
                                  + vwap(anchor="day"|"week"|"month")
                                  + a named limits manifest; every error
                                    carries a line and column
```

## The headline capabilities

### Typed structs with methods

Declare a `type` with fields and behavior, construct instances with named fields,
and carry them across bars. State now has the shape of the problem instead of a
pile of parallel arrays.

```javascript title="scripts/probes/lang-types/band_struct_method.ks" lines wrap
//@version=2
define(title="Struct Methods", position="offchart", axis=true)

type Band {
  top: number,
  bottom: number,

  func width() {
    return this.top - this.bottom
  }
}

timeseries d = ohlcv(symbol=currentSymbol, exchange=currentExchange)
var band = Band.new(top=d.high[0], bottom=d.low[0])
plotLine(value=band.width(), colors=["#2563eb"], width=2, label=["Band width"], desc=["high minus low via a struct method"])
```


See [User-Defined Types](/kscript/core-concepts/user-defined-types).

### Self-managing drawings

Lines, boxes, labels, polylines, linefills, and tables are now **handles** you can
create and `.delete()`. Build supply/demand zones that remove themselves when price
mitigates them, or a live dashboard table that updates on the last bar.

See [Drawing Objects](/kscript/functions/drawing-objects).

### No-repaint multi-timeframe

`htf()` reads a **confirmed** higher timeframe with no look-ahead: the 4h value at
any bar uses only data that closed before that bar. The repaint trap that
`security()` invites in other languages is impossible by default. `ltf()` attaches
finer bars, and `request()` is one-line shorthand for loading another symbol.

See [Multi-Timeframe](/kscript/core-concepts/multi-timeframe).

### Multi-venue aggregation

A single script can load up to **20 distinct sources**. Sum real buy/sell flow
across four exchanges into one cumulative delta, or aggregate open interest across
venues — the kind of cross-market view that took one source per script in v2.

See [Multi-Source & Aggregation](/kscript/core-concepts/multi-source) and
[Data Sources](/kscript/core-concepts/data-sources) for all 18 source types.

### A reference-validated TA library

70+ canonical indicators, each matching an independent reference implementation.
Multi-output indicators expose **named streams**: `bb.upper`, `macd.signal`,
`stoch.k`, `supertrend.direction` — no more positional guesswork.

See the [TA Library](/kscript/functions/ta-library) and
[Named Streams](/kscript/core-concepts/named-streams).

### Session-anchored VWAP

`vwap(anchor="day" | "week" | "month")` resets on real UTC session boundaries
instead of drifting with however much history happened to load. The no-argument
form is the familiar cumulative VWAP.

See [Special Indicators](/kscript/functions/special-indicators).

## Compatibility

- **Every v2 script keeps running.** v3 is additive.
- **Eight TA builtins were corrected to their textbook forms** (`ema` seeding,
  `rsi` Wilder smoothing, `macd`, `psar`, `adx`, `highest`/`lowest`, strict `sma`
  warmup). Early-bar values change for those functions; this is a correction, not
  a regression, since each now matches an independent reference.
- A few v2 conveniences were tightened or renamed; the
  [v2 vs v3 migration guide](/kscript/migrations/v2-vs-v3) lists them.

## The version marker

A v3 script still starts with `//@version=2` on its first line. The number is the
**script-format marker**, not the engine version — and it must be `//@version=2`.
Do not write `//@version=3`: the engine does not recognize it and falls back. All
of the v3 capabilities above compile and run under the `//@version=2` marker.

```javascript title="scripts/probes/lang-variables/var_timeseries_basic.ks" lines wrap
//@version=2
define(title="v3 under the v2 marker", position="offchart", axis=true)

timeseries d = ohlcv(symbol=currentSymbol, exchange=currentExchange)
timeseries sma20 = sma(source=d.close, period=20)
plotLine(value=sma20, colors=["#2563eb"], width=2, label=["SMA 20"], desc=["v3 features run under //@version=2"])
```


If something does not behave as documented, the
[Common Errors](/kscript/faq/common-errors) page maps every real engine error
message to its cause and fix.