diff --git a/backend/service-privateroom/auth.js b/backend/service-privateroom/auth.js
new file mode 100644
index 0000000..2cd2d5a
--- /dev/null
+++ b/backend/service-privateroom/auth.js
@@ -0,0 +1,28 @@
+const request = require('request');
+
+function getSession (req, callback) {
+    if(typeof req.headers.cookie !== 'undefined'){
+        request.post({
+            headers: {'content-type' : 'application/x-www-form-urlencoded'},
+            url: 'http://127.0.0.1:3000/verify:token',
+            body: 'sessionid='+req.headers.cookie.replace('SESSIONID=','')
+        },function (error, response, body) {
+            const bodyJson = JSON.parse(body);
+            if (bodyJson && bodyJson.status && bodyJson.data) {
+                if (bodyJson.status === 'ok') {
+                    return callback(bodyJson.data.token);
+                } else {
+                    return callback(bodyJson.data.reason);
+                }
+            }
+        });
+    }
+    return callback(undefined);
+}
+module.exports.getSession = getSession;
+
+function getUsername(session) {
+    if (typeof session === 'undefined' || typeof session.username === 'undefined') return -1;
+    return session.username;
+}
+module.exports.getUsername = getUsername;
diff --git a/backend/service-privateroom/config.js b/backend/service-privateroom/config.js
new file mode 100644
index 0000000..dd1ff91
--- /dev/null
+++ b/backend/service-privateroom/config.js
@@ -0,0 +1,15 @@
+const config = {
+    mongodbDatabase: 'chat',
+    mongodbHost:     'mongodb://127.0.0.1:27021/',
+    // mongodbHost:     'mongodb://127.0.0.1:27018/', //when commit
+    charset:       'utf8',
+    mongodbLogin:  '',
+    mongodbPassword: '',
+
+    mongodbPrivatedMessages: 'privatedmessages',
+    mongodbConversations: 'conversations'
+};
+module.exports = config;
+
+
+
diff --git a/backend/service-privateroom/message.js b/backend/service-privateroom/message.js
new file mode 100644
index 0000000..05714bc
--- /dev/null
+++ b/backend/service-privateroom/message.js
@@ -0,0 +1,13 @@
+// renvoie un message au format JSON. On a besoin de passer en paramètre
+// res, la réponse que l'on envoie au client (Angular). Le paramètre
+// data est un objet JavaScript. Globalement, cette fonction est
+// équivalente au "echo json_encode(data);" que vous utilisiez en PHP
+function sendMessage (res, data) {
+    res.json ({ status: 'ok', data: data });
+}
+
+function sendError (res, reason) {
+    res.json ({ status: 'error', data: {reason: reason }});
+}
+
+module.exports = { sendMessage, sendError };
diff --git a/backend/service-privateroom/models/Conversation.js b/backend/service-privateroom/models/Conversation.js
new file mode 100644
index 0000000..93b215d
--- /dev/null
+++ b/backend/service-privateroom/models/Conversation.js
@@ -0,0 +1,22 @@
+const mongoose = require("mongoose");
+const config = require("../config");
+
+const url = config.mongodbHost+config.mongodbDatabase;
+
+mongoose.connect(url,({useNewUrlParser: true, useUnifiedTopology: true})).then( function(){
+    console.log('mongodb-conversation connected '+mongoose.connection.readyState);
+}).catch(function(err){
+    console.log('error : '+err);
+});
+
+const ConversationSchema = new mongoose.Schema(
+    {
+        members: {
+            type: Array
+        },
+    },
+    { timestamps: true },
+    { versionKey: false }
+);
+
+module.exports = mongoose.model(config.mongodbConversations, ConversationSchema);
\ No newline at end of file
diff --git a/backend/service-privateroom/models/Message.js b/backend/service-privateroom/models/Message.js
new file mode 100644
index 0000000..d5f380a
--- /dev/null
+++ b/backend/service-privateroom/models/Message.js
@@ -0,0 +1,31 @@
+const mongoose = require("mongoose")
+const config = require("../config");
+
+const url = config.mongodbHost+config.mongodbDatabase;
+
+mongoose.connect(url,({useNewUrlParser: true, useUnifiedTopology: true})).then( function(){
+    console.log('mongodb-privated-room connected '+mongoose.connection.readyState);
+}).catch(function(err){
+    console.log('error : '+err);
+});
+
+const MessageSchema = new mongoose.Schema(
+    {
+        conversationId: {
+            type: String
+        },
+        sender: {
+            type: String
+        },
+        text: {
+            type: String
+        },
+        date:{
+            type: Date,
+        },
+    },
+    { timestamps: true },
+    { versionKey: false }
+);
+
+module.exports = mongoose.model(config.mongodbPrivatedMessages, MessageSchema);
\ No newline at end of file
diff --git a/backend/service-privateroom/package.json b/backend/service-privateroom/package.json
new file mode 100644
index 0000000..b148d96
--- /dev/null
+++ b/backend/service-privateroom/package.json
@@ -0,0 +1,25 @@
+{
+  "name": "service-privateroom",
+  "version": "1.0.0",
+  "description": "",
+  "main": "server.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "body-parser": "^1.19.0",
+    "cookie-parser": "^1.4.5",
+    "cors": "^2.8.5",
+    "express": "^4.17.1",
+    "fs": "0.0.1-security",
+    "jsonwebtoken": "^8.5.1",
+    "mongoose": "^5.12.11",
+    "socket.io": "^4.1.2"
+  },
+  "devDependencies": {
+    "request": "^2.88.2"
+  }
+}
diff --git a/backend/service-privateroom/routes/conversations.js b/backend/service-privateroom/routes/conversations.js
new file mode 100644
index 0000000..fc5654e
--- /dev/null
+++ b/backend/service-privateroom/routes/conversations.js
@@ -0,0 +1,28 @@
+const router = require("express").Router();
+const Conversation = require("../models/Conversation");
+const {sendError, sendMessage} = require ("../message");
+
+// new conv
+router.post("/newConv", async (req, res) => {
+    const newConversation = new Conversation({
+        members: [req.body.sender, req.body.receiver]
+    });
+
+    try{
+        const savedConversation = await newConversation.save();
+        sendMessage(res,savedConversation);
+    }catch (err){
+        sendMessage(res,err);
+    }
+});
+
+// get conv
+router.post("/getConv", async (req, res) => {
+    try {
+        const conversation = await Conversation.findOne({$or: [{members: {$eq: [req.body.sender,req.body.receiver]}},{members: {$eq: [req.body.receiver,req.body.sender]}}]},{_id:1});
+        sendMessage(res,conversation);
+    }catch (err){
+        sendMessage(res,err);
+    }
+})
+module.exports = router;
\ No newline at end of file
diff --git a/backend/service-privateroom/server.js b/backend/service-privateroom/server.js
new file mode 100644
index 0000000..76073bc
--- /dev/null
+++ b/backend/service-privateroom/server.js
@@ -0,0 +1,102 @@
+const express = require('express');
+const app = express();
+const port = process.env.PORT || 3002;
+const http = require('http');
+const { Server } = require("socket.io");
+const server = http.createServer(app);
+const io = new Server(server, {
+    cors: {
+        origin: "http://127.0.0.1:4200",
+        methods: ["GET", "POST"],
+        credentials: true
+    }
+});
+
+const bodyParser = require('body-parser');
+app.use(bodyParser.urlencoded({extended:true}));
+app.use(bodyParser.json());
+
+const cookieParser = require('cookie-parser');
+app.use(cookieParser());
+
+const cors = require('cors');
+app.use(cors({origin: 'http://127.0.0.1:4200', credentials: true}));
+
+const auth = require("./auth");
+
+const Conversation = require("../service-privateroom/models/Conversation");
+const Message = require("../service-privateroom/models/Message");
+const conversationRoute = require("./routes/conversations");
+app.use("/conversations", conversationRoute);
+
+io.on('connection',socket => {
+
+    auth.getSession(socket.request, function(res){
+        const getUsername = auth.getUsername(res);
+        if (getUsername === -1) {
+            socket.send('error','not authenticated');
+        }
+        else{
+            //TODO apply conversations and messages
+            socket.on('privateroom',function(data){
+                console.log(`${getUsername} joined the chat.`);
+                const sender = data.sender;
+                const receiver = data.receiver;
+                const date = data.date;
+                const message = data.message;
+
+                // get conversationId
+                let conversation = async () => {
+                    try {
+                        const result = await Conversation.find({
+                            members: {$eq: [sender, receiver]},
+                        });
+                        return result[0]["_id"];
+                    }catch (err){
+                    }
+                }
+
+                console.log('1azd',conversation);
+
+                if (conversation === null){
+                    const newConversation = new Conversation({
+                        members: [sender, receiver]
+                    });
+                    let result = async () => {
+                        try{
+                            const savedConversation = await newConversation.save();
+                            return savedConversation;
+                        }catch (err){
+                        }
+                    }
+                    conversation = result;
+                }
+                console.log('2 ac',conversation);
+                const conversationId = conversation["_id"];
+
+
+                Message.insertMany([{
+                    conversationId: conversationId,
+                    sender: sender,
+                    text: message,
+                    date: date
+                }
+                ]).then(function(){
+                    console.log(data, "inserted");
+                    socket.broadcast.emit(conversationId,[data]);
+                    socket.emit(conversationId,[data]);
+                }).catch(function(error){
+                    console.log("error",error);
+                });
+            });
+
+            socket.on("disconnect", function() {
+                console.log(`${getUsername} left the chat.`);
+            });
+        }
+    });
+});
+
+server.listen(port, () => {
+    console.log(`listening on *:${port}/`);
+});
\ No newline at end of file