diff --git a/README.md b/README.md
deleted file mode 100644
index d86263b..0000000
--- a/README.md
+++ /dev/null
@@ -1,2 +0,0 @@
-# todo
-레벨2
diff --git a/class/app.js b/class/app.js
new file mode 100644
index 0000000..2d67124
--- /dev/null
+++ b/class/app.js
@@ -0,0 +1,55 @@
+const readLine = require('readline').createInterface( {
+	input:process.stdin,
+	output:process.stdout,
+});
+const CommandParser = require('./commandParser.js');
+const Utils = require('./utils.js');
+const Instruction = require('./instruction.js');
+const CustomException = require('./customException.js');
+
+const RunTodoApp = class {
+	constructor() {
+		this.cmdArr = ['show','delete','update','add','undo','redo'];
+		this.commandParser = new CommandParser();
+		this.utils = new Utils();
+		this.instruction = new Instruction();
+		this.customException = new CustomException();	
+	}
+
+	 runProgram (readline) {
+       readline.setPrompt('명령하세요: ');
+       readline.prompt();
+       readline.on('line', (userInput) => {	    
+
+        try {
+           
+            this.customException.missingSeperatorException(userInput);
+            const cmdList = this.commandParser.getCmdList(userInput);
+            
+            this.customException.CommandMissingException(cmdList[0], this.cmdArr);
+            this.commandParser.executeCmd(cmdList);
+
+            this.utils.delay(0)
+            .then(() => {if (cmdList[0] === 'update') return this.utils.delay(3500);})
+            .then(() => {return this.utils.delay(1000);})
+            .then(() => {if (cmdList[0] !== 'show') this.instruction.show('all');})
+            .catch(function(e) {console.log(e);})
+            .then(() => {readLine.prompt();});
+       
+        } catch(e) {
+            console.error(e.message);
+            readLine.prompt();
+        }
+
+    }).on('close', () => {
+           console.log("프로그램을 종료합니다.");
+           process.exit();
+       });
+   }
+
+};
+
+const run = (() => {
+	const runTodoApp = new RunTodoApp();
+	runTodoApp.runProgram(readLine);
+})();
\ No newline at end of file
diff --git a/class/commandParser.js b/class/commandParser.js
new file mode 100644
index 0000000..8c4b88e
--- /dev/null
+++ b/class/commandParser.js
@@ -0,0 +1,42 @@
+const Instruction = require('./instruction.js');
+const CustomException = require('./customException.js');
+
+const CommandParser = class {
+	constructor() {
+		this.instruction = new Instruction();
+		this.customException = new CustomException();
+	}
+	
+	getCmdList(input) {
+    const regexp = /[^\$]+|undo|redo/g;
+    return input.match(regexp);
+	}
+	
+	executeCmd(command) {
+		try {
+			
+			if (command.length === 1) {
+				this.instruction[command[0]]();
+			} else if (command.length === 2) {
+				this.instruction[command[0]](command[1]);
+			} else if (command.length === 3) {
+				this.instruction[command[0]](command[1], command[2]);
+			} else {
+				this.customException.CommandMissingException();
+			}		
+			
+		} catch (e) {
+			console.error(e.message);
+			return;
+		}
+
+	}
+
+	isValidCommand(command, arr) {
+		let result = false;
+		if (arr.includes(command)) result = true;
+		return result;
+	}
+};
+
+module.exports = CommandParser;
\ No newline at end of file
diff --git a/class/customException.js b/class/customException.js
new file mode 100644
index 0000000..84db372
--- /dev/null
+++ b/class/customException.js
@@ -0,0 +1,34 @@
+const CustomException = class {
+	missingSeperatorException (input) {
+		if (!this.isValidSeperator(input)) throw new Error("구분자 $가 존재하지 않습니다");
+	}
+	
+	notExistIdException () {
+		throw new Error(`찾으시는 id가 존재하지 않습니다`);
+	}
+	
+	sameStatusException () {
+		throw new Error(`같은 상태로 업데이트 할 수 없습니다`);
+	}
+	
+	CommandMissingException (command, arr) {
+		if (!this.isValidCommand(command, arr))
+		throw new Error(`올바른 명령어가 아닙니다`);
+	}
+	
+	isValidSeperator (input) {
+		let result = true;
+		const regexp = /\$|undo|redo/g;
+		if (input.match(regexp) == null) result = false;
+		
+		return result;
+	}
+	
+	isValidCommand(command, arr) {
+    let result = false;
+    if (arr.includes(command)) result = true;
+    return result;
+	}
+};
+
+module.exports = CustomException;
\ No newline at end of file
diff --git a/class/instruction.js b/class/instruction.js
new file mode 100644
index 0000000..603f009
--- /dev/null
+++ b/class/instruction.js
@@ -0,0 +1,183 @@
+const originData = require('./todosdata.json');
+const convertedData = JSON.parse(JSON.stringify(originData)).data;
+const Utils = require('./utils.js');
+const CustomException = require('./customException.js');
+
+const Instruction = class {
+	constructor() {
+		this.utils = new Utils();
+		this.customException = new CustomException();
+		this.minIdNum = 1;
+        this.maxIdNum = 99999;
+        this.commandHistory = {
+			historyArr : [],
+			pointer : -1,
+		};
+	}
+	
+	everyStatus (convertedData) {
+		let [numOfTodos, numOfDoings, numOfDones] = [0,0,0];		
+		convertedData.forEach((value) => {
+			if (value.status === 'todo') numOfTodos++;
+			else if (value.status === 'doing') numOfDoings++;
+			else if (value.status === 'done') numOfDones++;				
+		});
+		console.log(`현재상태 : todo: ${numOfTodos}개, doing: ${numOfDoings}개, done: ${numOfDones}개`);
+	}
+	
+	singleStatus (convertedData, status) {
+		const tasks = this.utils.getArrByCondition(convertedData, (val) => { return (status === val.status);});
+		let message = `${status}리스트 총 ${tasks.length}건 : `;
+		tasks.forEach( obj => {
+			 message += `'${obj.name}, ${obj.id}번,' `;
+		});
+		console.log(message);
+	}
+
+    show(status) {
+		const statusArr = ['all', 'todo', 'doing', 'done'];
+		if (status === 'all') {
+			this.everyStatus(convertedData);
+		} else if (statusArr.includes(status)) {
+			this.singleStatus(convertedData, status);
+		}
+	}
+    
+    add(name, tags) {
+	    const id = this.utils.getRandomId(this.maxIdNum, this.minIdNum);
+		let obj = {
+			name, 
+			tags, 
+			status: 'todo', 
+			id,
+		};
+		convertedData.push(obj);
+		
+		if (arguments.length !== 3) {
+			this.createHistoryObj('add' ,obj);
+		}
+		
+		const message = `${obj.name} 1개가 추가됐습니다.(id : ${obj.id})`;
+		console.log(message);
+	}
+	
+    delete(id) {
+		const targetObj = this.utils.getArrByCondition(convertedData, (val) => { return id == val.id;})[0];
+		try {
+			if (!targetObj) this.customException.notExistIdException();
+		} catch (e) {
+			console.error(e.message);
+			return;
+		}
+		convertedData.splice(convertedData.indexOf(targetObj), 1);
+		
+		if (arguments.length == 1) {
+			this.createHistoryObj('delete', obj);
+		}
+		let message = `${targetObj.name}이 ${targetObj.status}에서 삭제되었습니다.`;
+		console.log(message);
+	}
+
+    update(id, status) {		
+		const targetObj = this.utils.getArrByCondition(convertedData, (val) => { return id == val.id;})[0];
+
+		try {
+			if (!targetObj) this.customException.notExistIdException();
+			if (targetObj.status === status) this.customException.sameStatusException();
+		} catch (e) {
+			console.error(e.message);
+			return;
+		}
+		
+        const preObj = this.utils.deepCopy(targetObj);
+		targetObj.status = status;
+		const nextObj = this.utils.deepCopy(targetObj);
+
+		if (arguments.length === 2) {
+			this.createHistoryObj('update', preObj, nextObj);
+		}
+		
+		const message = `${targetObj.name}가 ${targetObj.status}로 상태가 변경되었습니다`;
+		setTimeout(() => {
+        	console.log(message);
+	    }, 3000); 
+	}
+	
+	pushObj(arr, obj) {
+		if (arr.length === 3) {
+			arr.shift();
+			arr.push(obj);
+		} else {
+			arr.push(obj);	
+		}
+	}
+	
+	createHistoryObj(command, ...obj) {	
+		let historyObj = {};
+		
+		if (arguments.length == 3) { // update
+			historyObj = {
+				cmd: command,
+				pre: obj[0],
+				next: obj[1]
+			};
+	
+		} else if (arguments.length == 2) {  // add, delete
+			historyObj = {
+				cmd: command,
+				pre: obj[0]
+			};
+		}
+		
+		this.pushObj(this.commandHistory.historyArr, historyObj);
+		this.commandHistory.pointer++;
+    }
+    
+    undo() {
+		const targetObject = this.commandHistory.historyArr[this.commandHistory.pointer];
+		const [command, preObj, checkSum] = [targetObject.cmd, targetObject.pre, true];
+		
+		let message = ``;
+		
+		if (command === 'add') {
+			this.delete(preObj.id, checkSum);
+			message += `${preObj.id}번 항목 '${preObj.name}'가 ${preObj.status} 상태에서 삭제됐습니다`;
+			
+		} else if (command === 'delete') {
+			convertedData.push(preObj);
+			message += `${preObj.id}번 항목 '${preObj.name}'가 삭제에서 ${preObj.status} 상태로 변경됐습니다`;
+			
+		} else if (command === 'update') {
+			this.update(preObj.id, preObj.status, checkSum);
+		}
+		
+		console.log(message);
+		
+		if (this.commandHistory.pointer > -1) this.commandHistory.pointer--;
+    }	
+    
+    redo() {
+		if (this.commandHistory.pointer < 2) this.commandHistory.pointer++;
+		
+		const targetObject = this.commandHistory.historyArr[this.commandHistory.pointer];		
+		const [command, preObj, nextObj, checkSum] = [targetObject.cmd, targetObject.pre, targetObject.next, true];
+
+		let message = ``;
+
+		if (command === 'add') {
+			convertedData.push(preObj);
+			message += `${preObj.id}번 항목 '${preObj.name}'가 ${preObj.status}에 추가되었습니다`;
+			
+		} else if (command === 'delete') {
+			this.delete(preObj.id, checkSum);
+			message += `${preObj.id}번 항목 '${preObj.name}'가 ${preObj.status} 상태에서 삭제됐습니다`;
+			
+		} else if (command === 'update') {
+			this.update(nextObj.id, nextObj.status, checkSum);
+		}
+		console.log(message);
+	}
+
+};
+
+module.exports = Instruction;
\ No newline at end of file
diff --git a/class/todosdata.json b/class/todosdata.json
new file mode 100644
index 0000000..1734fe5
--- /dev/null
+++ b/class/todosdata.json
@@ -0,0 +1,41 @@
+{
+    "result" : true,
+    "data": [
+        {
+            "name" : "자바스크립트 공부하기", 
+            "tags" : ["programming", "javascript"],
+            "status" : "todo",
+            "id" : 12123123
+        },
+        {
+            "name" : "그림 그리기", 
+            "tags" : ["picture", "favorite"],
+            "status" : "doing",
+            "id" : 123
+        },
+        {
+            "name" : "파이썬 공부하기", 
+            "tags" : ["programming", "javascript"],
+            "status" : "done",
+            "id" : 213232
+        },
+        {
+            "name" : "자바 공부하기", 
+            "tags" : ["programming", "java"],
+            "status" : "todo",
+            "id" : 123345
+        },
+        {
+            "name" : "음악 듣기", 
+            "tags" : ["music", "favorite"],
+            "status" : "doing",
+            "id" : 12123
+        },
+        {
+            "name" : "정규식 공부하기", 
+            "tags" : ["programming", "RegExp"],
+            "status" : "done",
+            "id" : 1234
+        }   
+    ]
+}
diff --git a/class/utils.js b/class/utils.js
new file mode 100644
index 0000000..4645791
--- /dev/null
+++ b/class/utils.js
@@ -0,0 +1,31 @@
+const Utils  = class {
+
+	getArrByCondition (arr, condition) {
+        return arr.reduce((acc, val) => {
+            if (condition(val)) acc.push(val);
+            return acc;
+        }, []);
+    }	
+
+    getRandomId (max, min) {
+        return Math.floor(Math.random() * (max-min)) + 1;
+    }
+
+    delay (time) {
+		return new Promise(function(resolve, reject){
+			setTimeout(resolve, time);
+		});
+    }
+    
+    deepCopy (obj) {
+        if (obj === null || typeof(obj) !== "object") return obj;
+       
+        let copy = {};
+        for(let key in obj) {
+          copy[key] = this.deepCopy(obj[key]);
+        }
+        return copy;
+    }
+};
+
+module.exports = Utils;
\ No newline at end of file