📘 API for Custom Indicators

Read the attached [AI.txt] https://mobchart.com/docs/public/AI.txt file and use it as the only reference for the MobChart scripting API.

Create a custom indicator that plots a 20-period EMA and a 50-period EMA on the chart. Color the candles green when EMA20 is above EMA50 and red otherwise.

Use only the documented API. Do not invent functions. Return the complete indicator code.

define("My Indicator", "Shows EMA line", "onchart", true, false);

const length = input.number("Period", 14, 1, 100, 1);
const type = input.select("Type", 'sma', ['sma', 'ema']);
const color = input.color("Line Color", "#FF0000");

const length = style.number("Size", 14, 1, 100, 1);
const color = style.select("Background Color", '#FF0000', ["#FF0000", "#AA0000", "#BB0000"]);
const color = style.color("Background Color", "#FF0000");

[
    {
        "open": 115886.17,
        "high": 115911.96,
        "low": 115764.27,
        "close": 115815.16,
        "volume": 228.41528,
        "startTime": 1757699100000
    },
    {...},
    ...
]

[
    {
        "data": {
            "asks": {
                "109425": 5.467,
                "109495": 3.564,
                ...
            },
            "bids": {
                "33000": 3.746,
                "35000": 16.49,
                ...
            }
        },
        "startTime": 1757699100000
    },
    {...},
    ...
]

[
    {
        "data": {
            "totalBuy": 16053385,
            "totalSell": 20490989,
            "0.8654": { "buy": 286845, "sell": 336689 },
            "0.8653": { "buy": 271848, "sell": 259167 },
            "0.8652": { "buy": 318814, "sell": 373497 },
            ...
        },
        "startTime": 1757699100000
    },
    {...},
    ...
]

[
    {
        "data": {
            "totalBuy": 16053385,
            "totalSell": 20490989,
            "0.8654": { "buy": 286845, "sell": 336689 },
            "0.8653": { "buy": 271848, "sell": 259167 },
            "0.8652": { "buy": 318814, "sell": 373497 },
            ...
        },
        "startTime": 1757699100000
    },
    {...},
    ...
]

[
    {  
        "data": {
            "FR": 0.00003777, // Funding Rate
            "OI": { // Open Interest Candle
                "open": 85645.708,
                "close": 83496.225,
                "high": 85801.04,
                "low": 83397.918
            },
            "LS": { "l": 0.5426, "s": 0.4574 }, // Long/Short Ratio
            "taLS": { "l": 0.552, "s": 0.448 }, // Top Traders Account Ratio
            "tpLS": { "l": 0.5996, "s": 0.4004 } // Top Traders Position Ratio
        },
        "startTime": 1757699100000
    },
    {...},
    ...
]

const candles = source.ohlcv(); // The exchange, ticker, and timeframe parameters default to the current chart.
const closes = candles.map(c => c.close);

const candles = source.ohlcv(currentExchange, currentTicker, currentTimeframe);
const closes = candles.map(c => c.close);

const candles = source.ohlcv();
logger.log("First candle:", candles?.[0]);

plot.text("Text object", "Hello world!", 1757699100000, 115000, 10, "#00C8FF", 0.5);
plot.straightLine(`${namePrefix} Open`, level.timeStart, level.open, level.timeEnd, level.open, color);
plot.circle(`${namePrefix} High`, level.timeStart, level.high, 3, color);

plot.lineSeries("EMA", ta.ema(closes, 20), "#00C8FF");
plot.barSeries("Premium %", premiumPercents, ((d) => d > 0 ? color1 : color2), 1);
plot.candleSeries(
    "Candles",
    opens, closes, highs, lows,
    (v, i) => {
        return opens?.[i] > closes?.[i] ? colorBuy : colorSell
    }
);

const candles = source.ohlcv();
const closes = candles.map(c => c.close);
const rsiValues = ta.rsi(closes, 14);
plot.lineSeries("RSI", rsiValues, "#00C8FF");

const alertVolumeThreshold = alertInput.number("Volume threshold", 1000, 0, 10000000, 1);

if (candle.volume > alertVolumeThreshold) {
    alert.fire("High volume", `vol ${candle.volume}`, candle.startTime);
}

// simple: fires every time the shape is plotted for a new date
plot.box(...).alert("High volume", `vol ${candle.volume}`);

// callback: return nothing to skip, [title, message] to fire
plot.box(...).alert((shape) => {
    if (candle.volume > alertVolumeThreshold)
        alert.fire("High volume", `vol ${candle.volume}`, candle.startTime);
});

plot.lineSeries("RSI", rsiValues, color).alert((rsi, date) => {
    if (rsi > alertRsiThreshold) alert.fire("RSI high", `RSI ${rsi.toFixed(1)}`, latestCandle.startTime);
});

const title = "Volume alerts";
const description = "Shows boxes on high-volume candles";
define(title, description, "onchart", true, true);

const color = style.color("Color", "#00C8FF");
const volumeThreshold = input.number("Volume threshold", 1000, 0, 10000000, 1);
const alertVolumeThreshold = alertInput.number("Alert volume threshold", 5000, 0, 10000000, 1);
const alertCloseThreshold = alertInput.number("Alert close threshold", 100000, 0, 10000000, 1);

const candles = source.ohlcv();
const latestCandle = candles.at(-1);
const closes = candles.map(c => c.close);

// series alert: checks the latest close
plot.lineSeries("Closes", closes, color).alert((close, date) => {
    if (close > alertCloseThreshold) alert.fire("Close above threshold", `close ${close}`, latestCandle.startTime);
});

for (let i = 0; i < candles.length; i++) {
    const candle = candles[i];

    if (candle.volume > volumeThreshold) {
        const right = i < candles.length - 1 ? candles[i + 1].startTime : candle.startTime + 60000;

        // shape alert: checked against the user's alert threshold
        plot.box(`Volume ${i}`, candle.startTime, candle.high, right, candle.low, "#00C8FF", 0.3)
            .alert(() => {
                if (candle.volume > alertVolumeThreshold)
                    alert.fire("High volume", `vol ${candle.volume}`, candle.startTime);
            });
    }
}

const title = "Your first indicator";
const description = "Shows closes lines on the chart";
const indicatorType = "onchart";

define(title, description, type, true, true);

const color = input.color("Line Color", "#00C8FF");
const candles = source.ohlcv();
const closes = candles.map(c => c.close);
plot.lineSeries("Closes", closes, color);

define("Example Indicator", "Demonstrates basic plotting", "onchart", true, true);

const color = input.color("Line Color", "#00FF99");
const candles = source.ohlcv();
const closes = candles.map(c => c.close);

const ema20 = ta.ema(closes, 20);
plot.lineSeries("EMA 20", ema20, color);

const title = "Colored Volume Bars";  
const description = "Volumes colored based on candle direction.";  
const indicatorType = "onchart";  
const isPublic = true;  
const isPublicCode = true;  

define(title, description, indicatorType, isPublic, isPublicCode);  

// Get OHLC candles
const candles = source.ohlcv();  

const colorUp = style.color("Color 1", "#2BB462"); // Greenish color for rising prices
const colorDown = style.color("Color 2", "#FB4C51"); // Reddish color for falling prices
const volumes = candles.map(candle => candle.volume);  

plot.barSeries("Volume", volumes, (value, index) => {
    const currentCandle = candles[index];  
    return currentCandle.close >= currentCandle.open ? colorUp : colorDown;  
});

define('Coinbase Premium Index', 'Coinbase Premium Index', 'offchart', true, false);

const color1 = style.color("Color 1", "#2BB462");
const color2 = style.color("Color 2", "#FB4C51");

// Get OHLC candles
const cbCandles = source.ohlcv('coinbase', 'BTC-USD');
const binanceCandles = source.ohlcv('binance', 'BTCUSDT');

// Extract closes
const cbCloses = cbCandles.map(c => c.close);
const binanceCloses = binanceCandles.map(c => c.close);

// --- Coinbase Premium Index calculation ---
const premiumPercent = cbCloses.map((cb, i) => {
    const b = binanceCloses[i];
    return ((cb - b) / b) * 100;
});

// Plot premium index
plot.barSeries("Premium %", premiumPercent, ((d) => d > 0 ? color1 : color2)) // Percentage difference

const title = "Candles";
const description = "Simple candles draw";
const indicatorType = "offchart";
const isPublic = true;
const isPublicCode = true;
define(title, description, indicatorType, isPublic, isPublicCode);

const colorBuy = style.color("Buy Color", "#2BB462");
const colorSell = style.color("Sell Color", "#7a3d3f");
const candles = source.ohlcv();
const closes = candles.map(c => c.close);
const opens = candles.map(c => c.open);
const highs = candles.map(c => c.high);
const lows = candles.map(c => c.low);
plot.candleSeries(
    "Candles",
    opens, closes, highs, lows,
    (v, i) => {
        return opens?.[i] > closes?.[i] ? colorBuy : colorSell
    }
);