⚙️ Install

npm i @candleview/cvs-engine

yarn add @candleview/cvs-engine

DSL Built-in Functions

Data Access

• getClose() - Latest close price, returns number
• getOpen() - Latest open price, returns number
• getHigh() - Latest high price, returns number
• getLow() - Latest low price, returns number
• getVolume() - Latest volume, returns number
• getTime() - Latest timestamp, returns number
• getCloseAt(offset) - Historical close price, offset 0=latest, returns number
• getOpenAt(offset) - Historical open price, returns number
• getHighAt(offset) - Historical high price, returns number
• getLowAt(offset) - Historical low price, returns number
• getVolumeAt(offset) - Historical volume, returns number
• getBarCount() - Total bar count, returns number

Technical Indicators

• SMA(source, period) - Simple moving average, returns number
• EMA(source, period) - Exponential moving average, returns number
• WMA(source, period) - Weighted moving average, returns number
• SMMA(source, period) - Smoothed moving average, returns number
• RSI(source, period) - Relative strength index, period default 14, returns number
• MACD(source, fast, slow, signal) - MACD, returns {macd, signal, histogram}
• BOLL(source, period, stdDev) - Bollinger Bands, returns {upper, middle, lower}
• KDJ(highs, lows, closes, period) - KDJ indicator, returns {k, d, j}
• ATR(highs, lows, closes, period) - Average true range, returns number
• CCI(highs, lows, closes, period) - Commodity channel index, returns number
• ADX(highs, lows, closes, period) - Average directional index, returns number
• OBV(closes, volumes) - On-balance volume, returns number
• SAR(highs, lows, step, maxStep) - Parabolic SAR, returns number[]
• BBWIDTH(source, period, stdDev) - Bollinger band width, returns number

Chart Markers

• addTextMark(time, text, direction, options) - Add text marker, direction: 'up'|'down'
• addArrowUp(time, label, color) - Add up arrow marker
• addArrowDown(time, label, color) - Add down arrow marker
• clearAllMarks() - Clear all markers

Built-in Indicators Control

• openIndicator(name, params) - Open built-in indicator
• closeIndicator(name) - Close built-in indicator
• closeAllIndicators() - Close all built-in indicators

Custom Indicators

• plotMain(config) - Plot custom main chart indicator
• plotSub(config) - Plot custom sub chart indicator
• updateMain(id) - Update custom main indicator
• updateSub(id) - Update custom sub indicator
• removeMain(id) - Remove custom main indicator
• removeSub(id) - Remove custom sub indicator
• clearAllMain() - Clear all custom main indicators
• clearAllSub() - Clear all custom sub indicators

Custom Technical Graphics

Custom Main Chart Technical Graphics

plotMain(config)

Draws a custom main chart indicator (overlay on the candlestick chart)

Config Parameters:

| Field | Type | Description | | ---------- | -------- | ----------------------------------------------------------- | | id | string | Unique identifier for the indicator, used for update/remove | | calculator | function | Calculation function, called once per candlestick | | options | object | Optional, style configuration |

calculator Parameters:

| Parameter | Type | Description | | --------- | ------ | --------------------------------------------- | | index | number | Candlestick index (reverse order, 0 = latest) | | open | number | Current candlestick open price | | high | number | Current candlestick high price | | low | number | Current candlestick low price | | close | number | Current candlestick close price | | volume | number | Current candlestick volume |

options Configuration:

| Field | Type | Default | Description | | ------------ | --------------------------- | --------- | ---------------------- | | name | string | - | Indicator display name | | color | string | '#FF6B6B' | Line color | | width | number | 2 | Line width | | style | 'solid'|'dashed'|'dotted' | 'solid' | Line style | | visible | boolean | true | Visibility | | priceScaleId | string | 'right' | Price scale ID |

Example:

plotMain({
  id: "MA20",
  calculator: (index, open, high, low, close, volume) => {
    if (getBarCount() < 20) return null;
    let closes = [];
    for (let i = 0; i < 20; i++) closes.push(getCloseAt(i));
    return SMA(closes, 20);
  },
  options: {
    name: "MA20",
    color: "#FF6B6B",
    width: 2,
    style: "solid",
  },
});

plotSub(config)

Draws a custom sub chart indicator (independent panel)

Config Parameters:

| Field | Type | Description | | ---------- | -------- | ----------------------------------------------------------- | | id | string | Unique identifier for the indicator, used for update/remove | | calculator | function | Calculation function, called once per candlestick | | options | object | Optional, style configuration |

calculator Parameters:

| Parameter | Type | Description | | --------- | ------ | --------------------------------------------- | | index | number | Candlestick index (reverse order, 0 = latest) | | open | number | Current candlestick open price | | high | number | Current candlestick high price | | low | number | Current candlestick low price | | close | number | Current candlestick close price | | volume | number | Current candlestick volume |

options Configuration:

| Field | Type | Default | Description | | ------- | ------------------------------- | --------- | ---------------------- | | name | string | - | Indicator display name | | color | string | '#FF6B6B' | Line color | | width | number | 2 | Line width | | type | 'line' | 'histogram' | 'area' | 'line' | Chart type | | visible | boolean | true | Visibility |

Example:

plotSub({
  id: "RSI_14",
  calculator: (index, open, high, low, close, volume) => {
    if (getBarCount() < 15) return null;
    let closes = [];
    for (let i = 0; i < 15; i++) closes.push(getCloseAt(i));
    return RSI(closes, 14);
  },
  options: {
    name: "RSI(14)",
    color: "#FF6B6B",
    width: 2,
    type: "line",
  },
});