//import the package var RuleEngine = require('node-rules'); //define the rules var rules = [{ "condition": function(R) { R.when(this && (this.transactionTotal < 500)); }, "consequence": function(R) { this.result = false; R.stop(); } }]; /*as you can see above we removed the priority  and on properties for this example as they are optional.*/ //sample fact to run the rules on var fact = { "userIP": "27.3.4.5", "name":"user4", "application":"MOB2", "userLoggedIn":true, "transactionTotal":400, "cardType":"Credit Card", }; //initialize the rule engine var R = new RuleEngine(rules); //Now pass the fact on to the rule engine for results R.execute(fact,function(result){ if(result.result) console.log("\n-----Payment Accepted----\n"); else console.log("\n-----Payment Rejected----\n"); });