diff --git a/addons/im_livechat/static/src/legacy/models/public_livechat.js b/addons/im_livechat/static/src/legacy/models/public_livechat.js
index babf6c7dca1..0c920eb4382 100644
--- a/addons/im_livechat/static/src/legacy/models/public_livechat.js
+++ b/addons/im_livechat/static/src/legacy/models/public_livechat.js
@@ -39,8 +39,6 @@ const PublicLivechat = Class.extend(Mixins.EventDispatcherMixin, {
         this.setParent(params.parent);
         this.messaging = messaging;
 
-        this._id = params.data.id;
-
         /**
          * Initialize the internal data for typing feature on threads.
          *
@@ -293,7 +291,7 @@ const PublicLivechat = Class.extend(Mixins.EventDispatcherMixin, {
     toData() {
         return {
             folded: this.messaging.publicLivechatGlobal.publicLivechat.isFolded,
-            id: this._id,
+            id: this.messaging.publicLivechatGlobal.publicLivechat.id,
             message_unread_counter: this.messaging.publicLivechatGlobal.publicLivechat.unreadCounter,
             operator_pid: (
                 this.messaging.publicLivechatGlobal.publicLivechat.operator
diff --git a/addons/im_livechat/static/src/legacy/models/public_livechat_message.js b/addons/im_livechat/static/src/legacy/models/public_livechat_message.js
index 2691249db6c..15b01f6e99c 100644
--- a/addons/im_livechat/static/src/legacy/models/public_livechat_message.js
+++ b/addons/im_livechat/static/src/legacy/models/public_livechat_message.js
@@ -301,15 +301,6 @@ const PublicLivechatMessage = Class.extend({
             notif.notification_status === 'bounce'
         );
     },
-    /**
-     * State whether this message originates from a channel.
-     * By default, messages do not originate from a channel.
-     *
-     * @return {boolean}
-     */
-    originatesFromChannel() {
-        return false;
-    },
     /**
      * State whether this message has a subject
      * By default, messages do not have any subject.
diff --git a/addons/im_livechat/static/src/legacy/public_livechat_chatbot.js b/addons/im_livechat/static/src/legacy/public_livechat_chatbot.js
index 5fa95daaf87..fe1f0ed83a6 100644
--- a/addons/im_livechat/static/src/legacy/public_livechat_chatbot.js
+++ b/addons/im_livechat/static/src/legacy/public_livechat_chatbot.js
@@ -7,7 +7,7 @@ import time from 'web.time';
 import utils from 'web.utils';
 
 import LivechatButton from '@im_livechat/legacy/widgets/livechat_button';
-import { clear, increment, insertAndReplace } from '@mail/model/model_field_command';
+import { clear, increment, insertAndReplace, replace } from '@mail/model/model_field_command';
 
 const _t = core._t;
 const QWeb = core.qweb;
@@ -107,7 +107,7 @@ const QWeb = core.qweb;
     _chatbotAddMessage(message, options) {
         message.body = utils.Markup(message.body);
         this._addMessage(message, options);
-        if (this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._thread._folded || !this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom()) {
+        if (this.messaging.publicLivechatGlobal.publicLivechat.isFolded || !this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom()) {
             this.messaging.publicLivechatGlobal.publicLivechat.update({ unreadCounter: increment() });
         }
 
@@ -167,11 +167,13 @@ const QWeb = core.qweb;
             chatbot_script_id: this.messaging.publicLivechatGlobal.livechatButtonView.chatbot.scriptId,
         });
 
-        const welcomeMessagesIds = welcomeMessages.map(welcomeMessage => welcomeMessage._id);
+        const welcomeMessagesIds = welcomeMessages.map(welcomeMessage => welcomeMessage.id);
         this.messaging.publicLivechatGlobal.livechatButtonView.update({
-            messages: this.messaging.publicLivechatGlobal.livechatButtonView.messages.filter((message) => {
-                !welcomeMessagesIds.includes(message._id);
-            }),
+            messages: replace(
+                this.messaging.publicLivechatGlobal.livechatButtonView.messages.filter((message) => {
+                    !welcomeMessagesIds.includes(message.id);
+                }),
+            ),
         });
 
         postedWelcomeMessages.reverse();
@@ -444,7 +446,7 @@ const QWeb = core.qweb;
                 this.messaging.publicLivechatGlobal.livechatButtonView.messages.length !== 0
             ) {
                 const lastMessage = this.messaging.publicLivechatGlobal.livechatButtonView.messages[this.messaging.publicLivechatGlobal.livechatButtonView.messages.length - 1];
-                if (lastMessage.getAuthorID() !== this.messaging.publicLivechatGlobal.publicLivechat.operator.id) {
+                if (lastMessage.legacyPublicLivechatMessage.getAuthorID() !== this.messaging.publicLivechatGlobal.publicLivechat.operator.id) {
                     // we are on the last step of the script, expect a user input and the user has
                     // already answered
                     // -> end the script
@@ -542,7 +544,7 @@ const QWeb = core.qweb;
      */
     _getWelcomeMessages() {
         return this.messaging.publicLivechatGlobal.livechatButtonView.messages.filter((message) => {
-            return message._id && typeof message._id === 'string' && message._id.startsWith('_welcome_');
+            return message.id && typeof message.id === 'string' && message.id.startsWith('_welcome_');
         });
     },
     /**
@@ -552,7 +554,7 @@ const QWeb = core.qweb;
      */
     _isLastMessageFromCustomer() {
         const lastMessage = this.messaging.publicLivechatGlobal.livechatButtonView.messages.length !== 0 ? this.messaging.publicLivechatGlobal.livechatButtonView.messages[this.messaging.publicLivechatGlobal.livechatButtonView.messages.length - 1] : null;
-        return lastMessage && lastMessage.getAuthorID() !== this.messaging.publicLivechatGlobal.publicLivechat.operator.id;
+        return lastMessage && lastMessage.legacyPublicLivechatMessage.getAuthorID() !== this.messaging.publicLivechatGlobal.publicLivechat.operator.id;
     },
 
      //--------------------------------------------------------------------------
@@ -643,8 +645,8 @@ const QWeb = core.qweb;
 
         if (this.messaging.publicLivechatGlobal.livechatButtonView.messages.length !== 0) {
             const lastMessage = this.messaging.publicLivechatGlobal.livechatButtonView.messages[this.messaging.publicLivechatGlobal.livechatButtonView.messages.length - 1];
-            const stepAnswers = lastMessage.getChatbotStepAnswers();
-            if (stepAnswers && stepAnswers.length !== 0 && !lastMessage.getChatbotStepAnswerId()) {
+            const stepAnswers = lastMessage.legacyPublicLivechatMessage.getChatbotStepAnswers();
+            if (stepAnswers && stepAnswers.length !== 0 && !lastMessage.legacyPublicLivechatMessage.getChatbotStepAnswerId()) {
                 this._chatbotDisableInput(_t('Select an option above'));
             }
         }
@@ -766,7 +768,7 @@ const QWeb = core.qweb;
                 date: time.datetime_to_str(new Date()),
                 model: "mail.channel",
                 message_type: "comment",
-                res_id: this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id,
+                res_id: this.messaging.publicLivechatGlobal.publicLivechat.id,
             });
         }
 
@@ -874,12 +876,12 @@ const QWeb = core.qweb;
             // but here we only care about the very last one (the current step of the script)
             // reversing the this.messages variable seems like a bad idea because it could have
             // bad implications for other flows (as the reverse is in-place, not in a copy)
-            if (message.getChatbotStepId() === stepId) {
+            if (message.legacyPublicLivechatMessage.getChatbotStepId() === stepId) {
                 stepMessage = message;
             }
         }
-        const messageId = stepMessage.getID();
-        stepMessage.setChatbotStepAnswerId(selectedAnswer);
+        const messageId = stepMessage.id;
+        stepMessage.legacyPublicLivechatMessage.setChatbotStepAnswerId(selectedAnswer);
         this.messaging.publicLivechatGlobal.livechatButtonView.chatbot.currentStep.data.chatbot_selected_answer_id = selectedAnswer;
         this._renderMessages();
         this._chatbotSaveSession();
diff --git a/addons/im_livechat/static/src/legacy/widgets/livechat_button.js b/addons/im_livechat/static/src/legacy/widgets/livechat_button.js
index 96172c0d993..c96b4277138 100644
--- a/addons/im_livechat/static/src/legacy/widgets/livechat_button.js
+++ b/addons/im_livechat/static/src/legacy/widgets/livechat_button.js
@@ -9,7 +9,7 @@ import Widget from 'web.Widget';
 
 import PublicLivechatMessage from '@im_livechat/legacy/models/public_livechat_message';
 
-import { clear, insert, insertAndReplace } from '@mail/model/model_field_command';
+import { clear, insertAndReplace, link, replace } from '@mail/model/model_field_command';
 
 const _t = core._t;
 const QWeb = core.qweb;
@@ -92,34 +92,35 @@ const LivechatButton = Widget.extend({
      * @param {Object} [options={}]
      */
     _addMessage(data, options) {
-        const message = new PublicLivechatMessage(this, this.messaging, data);
+        const legacyMessage = new PublicLivechatMessage(this, this.messaging, data);
 
         const hasAlreadyMessage = _.some(this.messaging.publicLivechatGlobal.livechatButtonView.messages, function (msg) {
-            return message.getID() === msg.getID();
+            return legacyMessage.getID() === msg.id;
         });
         if (hasAlreadyMessage) {
             return;
         }
+        const message = this.messaging.models['PublicLivechatMessage'].insert({
+            id: data.id,
+            legacyPublicLivechatMessage: legacyMessage,
+        });
         if (this.messaging.publicLivechatGlobal.publicLivechat) {
             this.messaging.publicLivechatGlobal.publicLivechat.update({
-                messages: insert({
-                    id: data.id,
-                    legacyPublicLivechatMessage: message,
-                }),
+                messages: link(message),
             });
         }
 
         if (this.messaging.publicLivechatGlobal.publicLivechat && this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat) {
-            this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.addMessage(message);
+            this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.addMessage(legacyMessage);
         }
 
         if (options && options.prepend) {
             this.messaging.publicLivechatGlobal.livechatButtonView.update({
-                messages: [message, ...this.messaging.publicLivechatGlobal.livechatButtonView.messages],
+                messages: replace([message, ...this.messaging.publicLivechatGlobal.livechatButtonView.messages]),
             });
         } else {
             this.messaging.publicLivechatGlobal.livechatButtonView.update({
-                messages: [...this.messaging.publicLivechatGlobal.livechatButtonView.messages, message],
+                messages: replace([...this.messaging.publicLivechatGlobal.livechatButtonView.messages, message]),
             });
         }
     },
@@ -257,8 +258,8 @@ const LivechatButton = Widget.extend({
      * @private
      */
      _renderMessages() {
-        const shouldScroll = !this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._thread._folded && this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom();
-        this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._messages = this.messaging.publicLivechatGlobal.livechatButtonView.messages;
+        const shouldScroll = !this.messaging.publicLivechatGlobal.publicLivechat.isFolded && this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom();
+        this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._messages = this.messaging.publicLivechatGlobal.livechatButtonView.messages.map(message => message.legacyPublicLivechatMessage);
         this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow.render();
         if (shouldScroll) {
             this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.scrollToBottom();
@@ -311,7 +312,7 @@ const LivechatButton = Widget.extend({
                 body: this.messaging.publicLivechatGlobal.livechatButtonView.defaultMessage,
                 date: time.datetime_to_str(new Date()),
                 model: "mail.channel",
-                res_id: this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id,
+                res_id: this.messaging.publicLivechatGlobal.publicLivechat.id,
             }, { prepend: true });
         }
     },
@@ -328,7 +329,7 @@ const LivechatButton = Widget.extend({
         ev.stopPropagation();
         const isComposerDisabled = this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow.$('.o_thread_composer input').prop('disabled');
         const shouldAskFeedback = !isComposerDisabled && this.messaging.publicLivechatGlobal.livechatButtonView.messages.find(function (message) {
-            return message.getID() !== '_welcome';
+            return message.id !== '_welcome';
         });
         if (shouldAskFeedback) {
             this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow.toggleFold(false);
diff --git a/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.js b/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.js
index 247919e9a53..08426bd4a8c 100644
--- a/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.js
+++ b/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.js
@@ -96,7 +96,6 @@ const PublicLivechatView = Widget.extend({
         this._super();
     },
     /**
-     * @param {@im_livechat/legacy/models/public_livechat} thread the thread to render.
      * @param {Object} [options]
      * @param {integer} [options.displayOrder=ORDER.ASC] order of displaying
      *    messages in the thread:
@@ -109,15 +108,15 @@ const PublicLivechatView = Widget.extend({
      * @param {boolean} [options.scrollToBottom=false]
      * @param {boolean} [options.squashCloseMessages]
      */
-     render(thread, options) {
+    render(options) {
         let shouldScrollToBottomAfterRendering = false;
-        if (this._currentThreadID === thread._id && this.isAtBottom()) {
+        if (this._currentThreadID === this.messaging.publicLivechatGlobal.publicLivechat.id && this.isAtBottom()) {
             shouldScrollToBottomAfterRendering = true;
         }
-        this._currentThreadID = thread._id;
+        this._currentThreadID = this.messaging.publicLivechatGlobal.publicLivechat.id;
 
         // copy so that reverse do not alter order in the thread object
-        const messages = _.clone(thread.getMessages());
+        const messages = _.clone(this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.getMessages());
 
         const modeOptions = options.isCreateMode ? this._disabledOptions :
                                                     this._enabledOptions;
@@ -176,7 +175,7 @@ const PublicLivechatView = Widget.extend({
         }
 
         this.$el.html(QWeb.render('im_livechat.legacy.mail.widget.Thread', {
-            thread,
+            thread: this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat,
             displayAuthorMessages,
             options,
             ORDER,
@@ -231,30 +230,6 @@ const PublicLivechatView = Widget.extend({
         const bottomHiddenHeight = fullHeight - topHiddenHeight - visibleHeight;
         return bottomHiddenHeight < 5;
     },
-    /**
-     * Removes a message and re-renders the thread
-     *
-     * @param {integer} [messageID] the id of the removed message
-     * @param {mail.model.AbstractThread} thread the thread which contains
-     *   updated list of messages (so it does not contain any message with ID
-     *   `messageID`).
-     * @param {Object} [options] options for the thread rendering
-     */
-     removeMessageAndRender(messageID, thread, options) {
-        this._currentThreadID = thread._id;
-        return new Promise((resolve, reject) => {
-            this.$('.o_thread_message[data-message-id="' + messageID + '"]')
-            .fadeOut({
-                done: () => {
-                    if (this._currentThreadID === thread._id) {
-                        this.render(thread, options);
-                    }
-                    resolve();
-                },
-                duration: 200,
-            });
-        });
-    },
     /**
      * Scroll to the bottom of the thread
      */
diff --git a/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.xml b/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.xml
index 08cfa0d1b8b..e95655253da 100644
--- a/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.xml
+++ b/addons/im_livechat/static/src/legacy/widgets/public_livechat_view/public_livechat_view.xml
@@ -187,9 +187,6 @@
                     <t t-if="message.isLinkedToDocumentThread() and options.displayDocumentLinks">
                         <small>on</small> <a t-att-href="message.getURL()" t-att-data-oe-model="message.getDocumentModel()" t-att-data-oe-id="message.getDocumentID()" class="o_document_link"><t t-esc="message.getDocumentName()"/></a>
                     </t>
-                    <t t-if="message.originatesFromChannel() and (message.getOriginChannelID() !== thread._id)">
-                        (<small>from</small> <a t-att-data-oe-id="message.getOriginChannelID()" href="#">#<t t-esc="message.getOriginChannelName()"/></a>)
-                    </t>
                     <span t-attf-class="o_thread_icons">
                         <i t-if="message.isNeedaction() and options.displayMarkAsRead"
                            class="fa fa-check o_thread_icon o_thread_message_needaction"
diff --git a/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.js b/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.js
index a727f95c3f0..77ccad96424 100644
--- a/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.js
+++ b/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.js
@@ -40,8 +40,6 @@ const PublicLivechatWindow = Widget.extend({
         this.messaging = messaging;
         this.options = options;
 
-        this._thread = thread;
-
         this._debouncedOnScroll = _.debounce(this._onScroll.bind(this), 100);
     },
     /**
@@ -54,14 +52,14 @@ const PublicLivechatWindow = Widget.extend({
         const options = {
             displayMarkAsRead: false,
         };
-        if (this._thread && this._thread._type === 'document_thread') {
+        if (this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._type === 'document_thread') {
             options.displayDocumentLinks = false;
         }
         this._publicLivechatView = new PublicLivechatView(this, this.messaging, options);
 
         // animate the (un)folding of thread windows
         this.$el.css({ transition: 'height ' + this.FOLD_ANIMATION_DURATION + 'ms linear' });
-        if (this._thread._folded) {
+        if (this.messaging.publicLivechatGlobal.publicLivechat.isFolded) {
             this.$el.css('height', this.HEIGHT_FOLDED);
         } else {
             this._focusInput();
@@ -107,7 +105,7 @@ const PublicLivechatWindow = Widget.extend({
      */
     render() {
         this.renderHeader();
-        this._publicLivechatView.render(this._thread, { displayLoadMore: false });
+        this._publicLivechatView.render({ displayLoadMore: false });
     },
     /**
      * Render the header of this thread window.
@@ -120,7 +118,7 @@ const PublicLivechatWindow = Widget.extend({
         this.$header.html(
             qweb.render('im_livechat.legacy.PublicLivechatWindow.HeaderContent', {
                 status: this.messaging.publicLivechatGlobal.publicLivechat.status,
-                thread: this._thread,
+                thread: this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat,
                 title: this.messaging.publicLivechatGlobal.publicLivechat.name,
                 unreadCounter: this.messaging.publicLivechatGlobal.publicLivechat.unreadCounter,
                 widget: this,
@@ -159,11 +157,11 @@ const PublicLivechatWindow = Widget.extend({
      * that has been changed.
      */
     updateVisualFoldState() {
-        if (!this._thread._folded) {
+        if (!this.messaging.publicLivechatGlobal.publicLivechat.isFolded) {
             this._publicLivechatView.scrollToBottom();
             this._focusInput();
         }
-        const height = this._thread._folded ? this.HEIGHT_FOLDED : this.HEIGHT_OPEN;
+        const height = this.messaging.publicLivechatGlobal.publicLivechat.isFolded ? this.HEIGHT_FOLDED : this.HEIGHT_OPEN;
         this.$el.css({ height });
     },
 
@@ -206,7 +204,7 @@ const PublicLivechatWindow = Widget.extend({
      */
     _postMessage(messageData) {
         this.trigger_up('post_message_chat_window', { messageData });
-        this._thread.postMessage(messageData)
+        this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.postMessage(messageData)
             .then(() => {
                 this._publicLivechatView.scrollToBottom();
             });
@@ -228,9 +226,9 @@ const PublicLivechatWindow = Widget.extend({
         ev.preventDefault();
         if (
             this.messaging.publicLivechatGlobal.publicLivechat.unreadCounter > 0 &&
-            !this._thread._folded
+            !this.messaging.publicLivechatGlobal.publicLivechat.isFolded
         ) {
-            this._thread.markAsRead();
+            this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.markAsRead();
         }
         this.close();
     },
@@ -271,7 +269,7 @@ const PublicLivechatWindow = Widget.extend({
      */
     _onInput() {
         const isTyping = this.$input.val().length > 0;
-        this._thread.setMyselfTyping({ typing: isTyping });
+        this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.setMyselfTyping({ typing: isTyping });
     },
     /**
      * Called when typing something on the composer of this thread window.
@@ -307,7 +305,7 @@ const PublicLivechatWindow = Widget.extend({
      */
     _onScroll() {
         if (this._publicLivechatView.isAtBottom()) {
-            this._thread.markAsRead();
+            this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat.markAsRead();
         }
     },
     /**
diff --git a/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.xml b/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.xml
index 6766793d952..77592af7fd8 100644
--- a/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.xml
+++ b/addons/im_livechat/static/src/legacy/widgets/public_livechat_window/public_livechat_window.xml
@@ -4,13 +4,13 @@
         @param {im_livechat.legacy.PublicLivechatWindow} widget
     -->
     <t t-name="im_livechat.legacy.PublicLivechatWindow">
-        <div class="o_thread_window o_in_home_menu" t-att-data-thread-id="widget._thread._id">
+        <div class="o_thread_window o_in_home_menu" t-att-data-thread-id="widget.messaging.publicLivechatGlobal.publicLivechat.id">
             <div class="o_thread_window_header">
                 <t t-call="im_livechat.legacy.PublicLivechatWindow.HeaderContent">
                     <t t-set="status" t-value="widget.messaging.publicLivechatGlobal.publicLivechat.status"/>
                     <t t-set="title" t-value="widget.messaging.publicLivechatGlobal.publicLivechat.name"/>
                     <t t-set="unreadCounter" t-value="widget.messaging.publicLivechatGlobal.publicLivechat.unreadCounter"/>
-                    <t t-set="thread" t-value="widget._thread"/>
+                    <t t-set="thread" t-value="widget.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat"/>
                 </t>
             </div>
             <div class="o_thread_window_content">
diff --git a/addons/im_livechat/static/src/models/livechat_button_view.js b/addons/im_livechat/static/src/models/livechat_button_view.js
index 706a9cffa2b..3fcaf91eb8a 100644
--- a/addons/im_livechat/static/src/models/livechat_button_view.js
+++ b/addons/im_livechat/static/src/models/livechat_button_view.js
@@ -1,7 +1,7 @@
 /** @odoo-module **/
 
 import { registerModel } from '@mail/model/model_core';
-import { attr, one } from '@mail/model/model_field';
+import { attr, many, one } from '@mail/model/model_field';
 import { clear, insertAndReplace } from '@mail/model/model_field_command';
 
 registerModel({
@@ -263,9 +263,7 @@ registerModel({
         localStorageChatbotState: attr({
             compute: '_computeLocalStorageChatbotState',
         }),
-        messages: attr({
-            default: [],
-        }),
+        messages: many('PublicLivechatMessage'),
         publicLivechatGlobalOwner: one('PublicLivechatGlobal', {
             inverse: 'livechatButtonView',
             readonly: true,
diff --git a/addons/im_livechat/static/src/models/public_livechat.js b/addons/im_livechat/static/src/models/public_livechat.js
index cd26ae84105..844166361e7 100644
--- a/addons/im_livechat/static/src/models/public_livechat.js
+++ b/addons/im_livechat/static/src/models/public_livechat.js
@@ -23,6 +23,16 @@ registerModel({
         },
     },
     recordMethods: {
+        /**
+         * @private
+         * @returns {integer|FieldCommand}
+         */
+        _computeId() {
+            if (!this.data) {
+                return clear();
+            }
+            return this.data.id;
+        },
         /**
          * @private
          * @returns {FieldCommand|string}
@@ -75,6 +85,9 @@ registerModel({
     },
     fields: {
         data: attr(),
+        id: attr({
+            compute: '_computeId',
+        }),
         isFolded: attr({
             default: false,
         }),
diff --git a/addons/im_livechat/static/src/models/public_livechat_global_notification_handler.js b/addons/im_livechat/static/src/models/public_livechat_global_notification_handler.js
index db95dcc5d9d..ca25f5c54c5 100644
--- a/addons/im_livechat/static/src/models/public_livechat_global_notification_handler.js
+++ b/addons/im_livechat/static/src/models/public_livechat_global_notification_handler.js
@@ -27,7 +27,7 @@ registerModel({
         _handleNotification({ payload, type }) {
             switch (type) {
                 case 'im_livechat.history_command': {
-                    if (payload.id !== this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id) {
+                    if (payload.id !== this.messaging.publicLivechatGlobal.publicLivechat.id) {
                         return;
                     }
                     const cookie = utils.get_cookie(this.messaging.publicLivechatGlobal.LIVECHAT_COOKIE_HISTORY);
@@ -40,7 +40,7 @@ registerModel({
                     return;
                 }
                 case 'mail.channel.member/typing_status': {
-                    if (payload.channel_id !== this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id) {
+                    if (payload.channel_id !== this.messaging.publicLivechatGlobal.publicLivechat.id) {
                         return;
                     }
                     const partnerID = payload.partner_id;
@@ -56,28 +56,28 @@ registerModel({
                     return;
                 }
                 case 'mail.channel/new_message': {
-                    if (payload.id !== this.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id) {
+                    if (payload.id !== this.messaging.publicLivechatGlobal.publicLivechat.id) {
                         return;
                     }
                     const notificationData = payload.message;
                     // If message from notif is already in chatter messages, stop handling
-                    if (this.messaging.publicLivechatGlobal.livechatButtonView.messages.some(message => message.getID() === notificationData.id)) {
+                    if (this.messaging.publicLivechatGlobal.livechatButtonView.messages.some(message => message.id === notificationData.id)) {
                         return;
                     }
                     notificationData.body = utils.Markup(notificationData.body);
                     this.messaging.publicLivechatGlobal.livechatButtonView.widget._addMessage(notificationData);
-                    if (this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._thread._folded || !this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom()) {
+                    if (this.messaging.publicLivechatGlobal.publicLivechat.isFolded || !this.messaging.publicLivechatGlobal.livechatButtonView.chatWindow.legacyChatWindow._publicLivechatView.isAtBottom()) {
                         this.messaging.publicLivechatGlobal.publicLivechat.update({ unreadCounter: increment() });
                     }
                     this.messaging.publicLivechatGlobal.livechatButtonView.widget._renderMessages();
                     return;
                 }
                 case 'mail.message/insert': {
-                    const message = this.messaging.publicLivechatGlobal.livechatButtonView.messages.find(message => message._id === payload.id);
+                    const message = this.messaging.publicLivechatGlobal.livechatButtonView.messages.find(message => message.id === payload.id);
                     if (!message) {
                         return;
                     }
-                    message._body = utils.Markup(payload.body);
+                    message.legacyPublicLivechatMessage._body = utils.Markup(payload.body);
                     this.messaging.publicLivechatGlobal.livechatButtonView.widget._renderMessages();
                     return;
                 }
diff --git a/addons/website_livechat/static/tests/tours/website_livechat_common.js b/addons/website_livechat/static/tests/tours/website_livechat_common.js
index 7d86ae248b8..9544ea45a2f 100644
--- a/addons/website_livechat/static/tests/tours/website_livechat_common.js
+++ b/addons/website_livechat/static/tests/tours/website_livechat_common.js
@@ -30,7 +30,7 @@ LivechatButton.include({
                         self.messaging.publicLivechatGlobal.notificationHandler._handleNotification({
                             type: 'mail.channel/new_message',
                             payload: {
-                                id: self.messaging.publicLivechatGlobal.publicLivechat.legacyPublicLivechat._id,
+                                id: self.messaging.publicLivechatGlobal.publicLivechat.id,
                                 message: {
                                     id: self.messaging.publicLivechatGlobal.livechatButtonView.messages.length + 1,
                                     author_id: [0, 'Website Visitor Test'],