Mã ví dụ cho API REST và WebSocket của NodeJs

const axios = require("axios");
const crypto = require('crypto');
const WebSocket = require('ws');


const Main = async () => {

    //TODO: UPDATE WITH YOUR KEYS :)
    let apiPublicKey = "YOUR_PUBLIC_KEY"
    let apiPrivateKey = "YOUR_PRIVATE_KEY"
    
    try {

        console.log("|=========================================|");
        console.log("|      KRAKEN.COM NODEJS TEST APP         |");
        console.log("|=========================================|");
        console.log();


        /*
        * PUBLIC REST API Examples
        */

        if (1 == 0) {
            let publicResponse = "";

            let publicEndpoint = "SystemStatus";
            let publicInputParameters = "";

            /*
            *MORE PUBLIC REST EXAMPLES
 
            let publicEndpoint = "AssetPairs";
            let publicInputParameters = "pair=ethusd,xbtusd";
 
            let publicEndpoint = "Ticker";
            let publicInputParameters = "pair=ethusd";
 
            let publicEndpoint = "Trades";
            let publicInputParameters = "pair=ethusd&since=0";
            */

            publicResponse = await QueryPublicEndpoint(publicEndpoint, publicInputParameters);
            console.log(publicResponse);

        }

        /*
        * PRIVATE REST API Examples
        */

        if (1 == 0) {
            let privateResponse = "";

            let privateEndpoint = "Balance";
            let privateInputParameters = "";

            /*
            *MORE PRIVATE REST EXAMPLES
    
            let privateEndpoint = "AddOrder";
            let privateInputParameters = "pair=xbteur&type=buy&ordertype=limit&price=1.00&volume=1";
    
            let privateEndpoint = "AddOrder"
            let privateInputParameters = "pair=xdgeur&type=sell&ordertype=limit&volume=3000&price=%2b10.0%" //Positive Percentage Example (%2 represtes +, which is a reseved character in HTTP)
    
            let privateEndpoint = "AddOrder"
            let privateInputParameters = "pair=xdgeur&type=sell&ordertype=limit&volume=3000&price=-10.0%" //Negative Percentage Example
    
            let privateEndpoint = "AddOrder"
            let privateInputParameters = "pair=xdgeur&type=buy&ordertype=market&volume=3000&userref=789" //Userref Example
    
            let privateEndpoint = "Balance" //{"error":[]} IS SUCCESS, Means EMPTY BALANCE
            let privateInputParameters = "" 
    
            let privateEndpoint = "QueryOrders" 
            let privateInputParameters = "txid=OFUSL6-GXIIT-KZ2JDJ" 
    
            let privateEndpoint = "AddOrder"
            let privateInputParameters = "pair=xdgusd&type=buy&ordertype=market&volume=5000"
    
            let privateEndpoint = "DepositAddresses"
            let privateInputParameters = "asset=xbt&method=Bitcoin" 
    
            let privateEndpoint = "DepositMethods"
            let privateInputParameters = "asset=eth" 
    
            let privateEndpoint = "WalletTransfer" 
            let privateInputParameters = "asset=xbt&to=Futures Wallet&from=Spot Wallet&amount=0.0045" 
    
            let privateEndpoint = "TradesHistory"
            let privateInputParameters = "start=1577836800&end=1609459200" 
    
            let privateEndpoint = "GetWebSocketsToken" 
            let privateInputParameters = ""
            */

            privateResponse = await QueryPrivateEndpoint(privateEndpoint, 
                                                        privateInputParameters,
                                                        apiPublicKey,
                                                        apiPrivateKey);
            console.log(privateResponse);
        }

        /*
        * PUBLIC WEBSOCKET Examples
        */

        if (1 == 0) {

            let publicWebSocketURL = "wss://ws.kraken.com/";
            let publicWebSocketSubscriptionMsg = '{ "event":"subscribe", "subscription":{"name":"trade"},"pair":["XBT/USD"] }';

            /*
            *MORE PUBLIC WEBSOCKET EXAMPLES
            
            let publicWebSocketSubscriptionMsg = "{ "event": "subscribe", "subscription": { "interval": 1440, "name": "ohlc"}, "pair": [ "XBT/EUR"]}";
            let publicWebSocketSubscriptionMsg = "{ "event": "subscribe", "subscription": { "name": "spread"}, "pair": [ "XBT/EUR","ETH/USD" ]}";
            */

            await OpenAndStreamWebSocketSubscription(publicWebSocketURL, publicWebSocketSubscriptionMsg);
        }

        /*
        * PRIVATE WEBSOCKET Examples
        */

        if (1 == 0) {

            let privateWebSocketURL = "wss://ws-auth.kraken.com/";

            //GET THE WEBSOCKET TOKEN FORM THE JSON RESPONSE 
            let webSocketToken = await QueryPrivateEndpoint("GetWebSocketsToken", "", apiPublicKey, apiPrivateKey);
            webSocketToken = webSocketToken['token'];

            /*
            *MORE PRIVATE WEBSOCKET EXAMPLES

            let privateWebSocketSubscriptionMsg = `{ "event": "subscribe", "subscription": { "name": "openOrders", "token": "${webSocketToken}"}}`;
            let privateWebSocketSubscriptionMsg = `{ "event": "subscribe", "subscription": { "name": "balances", "token": "${webSocketToken}"}}`;
            let privateWebSocketSubscriptionMsg = `{"event":"addOrder","reqid":1234,"ordertype":"limit","pair":"XBT/EUR","token":"${webSocketToken}","type":"buy","volume":"1", "price":"1.00"}`;
            */

            //REPLACE PLACEHOLDER WITH TOKEN
            privateWebSocketSubscriptionMsg = `{ "event": "subscribe", "subscription": { "name": "ownTrades", "token": "${webSocketToken}"}}`;

            await OpenAndStreamWebSocketSubscription(privateWebSocketURL, privateWebSocketSubscriptionMsg);
        }


        console.log("|=======================================|");
        console.log("| END OF PROGRAM - HAVE A GOOD DAY :)   |");
        console.log("|=======================================|");
        console.log("\n");

    }
    catch (e) {
        console.log();
        console.log("AN EXCEPTION OCCURED :(");
        console.log(e);
    }


    /*
    * Public REST API Endpoints
    */

    async function QueryPublicEndpoint(endPointName, inputParameters) {
        let jsonData;
        const baseDomain = "https://api.kraken.com";
        const publicPath = "/0/public/";
        const apiEndpointFullURL = baseDomain + publicPath + endPointName + "?" + inputParameters;
        
        jsonData = await axios.get(apiEndpointFullURL);
        return jsonData.data.result;
    }


    /*
    * Private REST API Endpoints
    */

    async function QueryPrivateEndpoint(endPointName, 
                                        inputParameters, 
                                        apiPublicKey, 
                                        apiPrivateKey) {
        const baseDomain = "https://api.kraken.com";
        const privatePath = "/0/private/";
        
        const apiEndpointFullURL = baseDomain + privatePath + endPointName;
        const nonce = Date.now().toString();
        const apiPostBodyData = "nonce=" + nonce + "&" + inputParameters;
       
        const signature = CreateAuthenticationSignature(apiPrivateKey,
                                                        privatePath,
                                                        endPointName,
                                                        nonce,
                                                        apiPostBodyData);
        
        const httpOptions =
        {
            headers: { 'API-Key': apiPublicKey, 'API-Sign': signature }
        };

        let jsonData = await axios.post(apiEndpointFullURL, apiPostBodyData, httpOptions);

        return jsonData.data.result;
    }


    /*
    * Authentication Algorithm
    */

    function CreateAuthenticationSignature(apiPrivateKey, 
                                            apiPath, 
                                            endPointName, 
                                            nonce,
                                            apiPostBodyData){

        const apiPost = nonce + apiPostBodyData;
        const secret = Buffer.from(apiPrivateKey, 'base64');
        const sha256 = crypto.createHash('sha256');
        const hash256 = sha256.update(apiPost).digest('binary');
        const hmac512 = crypto.createHmac('sha512', secret);
        const signatureString = hmac512.update(apiPath + endPointName + hash256, 'binary').digest('base64');
        return signatureString;
    }


    /*
    * WebSocket API
    */

    async function OpenAndStreamWebSocketSubscription(connectionURL, webSocketSubscription) {
        try {
            const webSocketClient = new WebSocket(connectionURL);

            webSocketClient.on('open', function open() {
                webSocketClient.send(webSocketSubscription);
            });

            webSocketClient.on('message', function incoming(wsMsg) {
                var d = new Date();
                var msgTime = d.getHours() + ":" + d.getMinutes() + ":" + d.getSeconds();
                console.log(msgTime + ": " + wsMsg);
            });

            webSocketClient.on('close', function close() {
                console.log("|==============================================|");
                console.log("|     END OF PROGRAM - HAVE A GOOD DAY :)      |");
                console.log("|==============================================|");
                console.log("\n");
            });

        }
        catch (e) {
            console.log();
            console.log("AN EXCEPTION OCCURED :(");
            console.log(e);
        }
    }
};


Main();