diff --git a/src/browser/app/profile/zen-browser.js b/src/browser/app/profile/zen-browser.js
index 5526df672..2761fb0ed 100644
--- a/src/browser/app/profile/zen-browser.js
+++ b/src/browser/app/profile/zen-browser.js
@@ -141,6 +141,7 @@ pref('zen.workspaces.open-new-tab-if-last-unpinned-tab-is-closed', true);
 pref('zen.workspaces.icons', '["⌚","⌛","⏪","⏫","⏬","⏰","⏳","⚽","⚾","⛄","⛅","⛎","⛔","⛪","⛲","⛳","⛵","⛺","⛽","✅","✊","✋","✨","❌","❎","❓","⭐","⭕","🀄","🃏","🆎","🆑","🆒","🆓","🆔","🆕","🆖","🆗","🆘","🆙","🆚","🈁","🈚","🈯","🈲","🈳","🈴","🈵","🈶","🈸","🈹","🈺","🉐","🉑","🌀","🌁","🌂","🌃","🌄","🌅","🌆","🌇","🌈","🌉","🌊","🌋","🌌","🌍","🌎","🌏","🌐","🌑","🌒","🌓","🌔","🌕","🌖","🌗","🌘","🌙","🌚","🌛","🌜","🌝","🌞","🌟","🌠","🌭","🌮","🌯","🌰","🌱","🌲","🌳","🌴","🌵","🌷","🌸","🌹","🌺","🌻","🌼","🌽","🌾","🌿","🍀","🍁","🍂","🍃","🍄","🍅","🍆","🍇","🍈","🍉","🍊","🍋","🍌","🍍","🍎","🍏","🍐","🍑","🍒","🍓","🍔","🍕","🍖","🍗","🍘","🍙","🍚","🍛","🍜","🍝","🍞","🍟","🍠","🍡","🍢","🍣","🍤","🍥","🍦","🍧","🍨","🍩","🍪","🍫","🍬","🍭","🍮","🍯","🍰","🍱","🍲","🍳","🍴","🍵","🍶","🍷","🍸","🍹","🍺","🍻","🍼","🍾","🍿","🎀","🎁","🎂","🎃","🎄","🎅","🎆","🎇","🎈","🎉","🎊","🎋","🎌","🎍","🎎","🎏","🎐","🎑","🎒","🎓","🎠","🎡","🎢","🎣","🎤","🎥","🎦","🎧","🎨","🎩","🎪","🎫","🎬","🎭","🎮","🎯","🎰","🎱","🎲","🎳","🎴","🎵","🎶","🎷","🎸","🎹","🎺","🎻","🎼","🎽","🎾","🎿","🏀","🏁","🏂","🏃","🏄","🏅","🏆","🏇","🏈","🏉","🏊","🏏","🏐","🏑","🏒","🏓","🏠","🏡","🏢","🏣","🏤","🏥","🏦","🏧","🏨","🏩","🏪","🏫","🏬","🏭","🏮","🏯","🏰","🏴","🏸","🏹","🏺","🏻","🏼","🏽","🏾","🏿","🐀","🐁","🐂","🐃","🐄","🐅","🐆","🐇","🐈","🐉","🐊","🐋","🐌","🐍","🐎","🐏","🐐","🐑","🐒","🐓","🐔","🐕","🐖","🐗","🐘","🐙","🐚","🐛","🐜","🐝","🐞","🐟","🐠","🐡","🐢","🐣","🐤","🐥","🐦","🐧","🐨","🐩","🐪","🐫","🐬","🐭","🐮","🐯","🐰","🐱","🐲","🐳","🐴","🐵","🐶","🐷","🐸","🐹","🐺","🐻","🐼","🐽","🐾","👀","👂","👃","👄","👅","👆","👇","👈","👉","👊","👋","👌","👍","👎","👏","👐","👑","👒","👓","👔","👕","👖","👗","👘","👙","👚","👛","👜","👝","👞","👟","👠","👡","👢","👣","👤","👥","👦","👧","👨","👩","👪","👫","👬","👭","👮","👯","👰","👱","👲","👳","👴","👵","👶","👷","👸","👹","👺","👻","👼","👽","👾","👿","💀","💁","💂","💃","💄","💅","💆","💇","💈","💉","💊","💋","💌","💍","💎","💏","💐","💑","💒","💓","💔","💕","💖","💗","💘","💙","💚","💛","💜","💝","💞","💟","💠","💡","💢","💣","💤","💥","💦","💧","💨","💩","💪","💫","💬","💭","💮","💯","💰","💱","💲","💳","💴","💵","💶","💷","💸","💹","💺","💻","💼","💽","💾","💿","📀","📁","📂","📃","📄","📅","📆","📇","📈","📉","📊","📋","📌","📍","📎","📏","📐","📑","📒","📓","📔","📕","📖","📗","📘","📙","📚","📛","📜","📝","📞","📟","📠","📡","📢","📣","📤","📥","📦","📧","📨","📩","📪","📫","📬","📭","📮","📯","📰","📱","📲","📳","📴","📵","📶","📷","📸","📹","📺","📻","📼","📿","🔀","🔁","🔂","🔃","🔄","🔅","🔆","🔇","🔈","🔉","🔊","🔋","🔌","🔍","🔎","🔏","🔐","🔑","🔒","🔓","🔔","🔕","🔖","🔗","🔘","🔙","🔚","🔛","🔜","🔝","🔞","🔟","🔠","🔡","🔢","🔣","🔤","🔥","🔦","🔧","🔨","🔩","🔪","🔫","🔬","🔭","🔮","🔯","🔰","🔱","🔲","🔳","🔴","🔵","🔶","🔷","🔸","🔹","🔺","🔻","🔼","🔽","🕋","🕌","🕍","🕎","🕐","🕑","🕒","🕓","🕔","🕕","🕖","🕗","🕘","🕙","🕚","🕛","🕜","🕝","🕞","🕟","🕠","🕡","🕢","🕣","🕤","🕥","🕦","🕧","🖕","🖖","🗻","🗼","🗽","🗾","🗿","😀","😁","😂","😃","😄","😅","😆","😇","😈","😉","😊","😋","😌","😍","😎","😏","😐","😑","😒","😓","😔","😕","😖","😗","😘","😙","😚","😛","😜","😝","😞","😟","😠","😡","😢","😣","😤","😥","😦","😧","😨","😩","😪","😫","😬","😭","😮","😯","😰","😱","😲","😳","😴","😵","😶","😷","😸","😹","😺","😻","😼","😽","😾","😿","🙀","🙁","🙂","🙃","🙄","🙅","🙆","🙇","🙈","🙉","🙊","🙋","🙌","🙍","🙎","🙏","🚀","🚁","🚂","🚃","🚄","🚅","🚆","🚇","🚈","🚉","🚊","🚋","🚌","🚍","🚎","🚏","🚐","🚑","🚒","🚓","🚔","🚕","🚖","🚗","🚘","🚙","🚚","🚛","🚜","🚝","🚞","🚟","🚠","🚡","🚢","🚣","🚤","🚥","🚦","🚧","🚨","🚩","🚪","🚫","🚬","🚭","🚮","🚯","🚰","🚱","🚲","🚳","🚴","🚵","🚶","🚷","🚸","🚹","🚺","🚻","🚼","🚽","🚾","🚿","🛀","🛁","🛂","🛃","🛄","🛅","🛌","🛐","🛫","🛬","🤐","🤑","🤒","🤓","🤔","🤕","🤖","🤗","🤘","🦀","🦁","🦂","🦃","🦄","🧀","🇦🇨","🇦🇩","🇦🇪","🇦🇫","🇦🇬","🇦🇮","🇦🇱","🇦🇲","🇦🇴","🇦🇶","🇦🇷","🇦🇸","🇦🇹","🇦🇺","🇦🇼","🇦🇽","🇦🇿","🇧🇦","🇧🇧","🇧🇩","🇧🇪","🇧🇫","🇧🇬","🇧🇭","🇧🇮","🇧🇯","🇧🇱","🇧🇲","🇧🇳","🇧🇴","🇧🇶","🇧🇷","🇧🇸","🇧🇹","🇧🇻","🇧🇼","🇧🇾","🇧🇿","🇨🇦","🇨🇨","🇨🇩","🇨🇫","🇨🇬","🇨🇭","🇨🇮","🇨🇰","🇨🇱","🇨🇲","🇨🇳","🇨🇴","🇨🇵","🇨🇷","🇨🇺","🇨🇻","🇨🇼","🇨🇽","🇨🇾","🇨🇿","🇩🇪","🇩🇬","🇩🇯","🇩🇰","🇩🇲","🇩🇴","🇩🇿","🇪🇦","🇪🇨","🇪🇪","🇪🇬","🇪🇭","🇪🇷","🇪🇸","🇪🇹","🇪🇺","🇫🇮","🇫🇯","🇫🇰","🇫🇲","🇫🇴","🇫🇷","🇬🇦","🇬🇧","🇬🇩","🇬🇪","🇬🇫","🇬🇬","🇬🇭","🇬🇮","🇬🇱","🇬🇲","🇬🇳","🇬🇵","🇬🇶","🇬🇷","🇬🇸","🇬🇹","🇬🇺","🇬🇼","🇬🇾","🇭🇰","🇭🇲","🇭🇳","🇭🇷","🇭🇹","🇭🇺","🇮🇨","🇮🇩","🇮🇪","🇮🇱","🇮🇲","🇮🇳","🇮🇴","🇮🇶","🇮🇷","🇮🇸","🇮🇹","🇯🇪","🇯🇲","🇯🇴","🇯🇵","🇰🇪","🇰🇬","🇰🇭","🇰🇮","🇰🇲","🇰🇳","🇰🇵","🇰🇷","🇰🇼","🇰🇾","🇰🇿","🇱🇦","🇱🇧","🇱🇨","🇱🇮","🇱🇰","🇱🇷","🇱🇸","🇱🇹","🇱🇺","🇱🇻","🇱🇾","🇲🇦","🇲🇨","🇲🇩","🇲🇪","🇲🇫","🇲🇬","🇲🇭","🇲🇰","🇲🇱","🇲🇲","🇲🇳","🇲🇴","🇲🇵","🇲🇶","🇲🇷","🇲🇸","🇲🇹","🇲🇺","🇲🇻","🇲🇼","🇲🇽","🇲🇾","🇲🇿","🇳🇦","🇳🇨","🇳🇪","🇳🇫","🇳🇬","🇳🇮","🇳🇱","🇳🇴","🇳🇵","🇳🇷","🇳🇺","🇳🇿","🇴🇲","🇵🇦","🇵🇪","🇵🇫","🇵🇬","🇵🇭","🇵🇰","🇵🇱","🇵🇲","🇵🇳","🇵🇷","🇵🇸","🇵🇹","🇵🇼","🇵🇾","🇶🇦","🇷🇪","🇷🇴","🇷🇸","🇷🇺","🇷🇼","🇸🇦","🇸🇧","🇸🇨","🇸🇩","🇸🇪","🇸🇬","🇸🇭","🇸🇮","🇸🇯","🇸🇰","🇸🇱","🇸🇲","🇸🇳","🇸🇴","🇸🇷","🇸🇸","🇸🇹","🇸🇻","🇸🇽","🇸🇾","🇸🇿","🇹🇦","🇹🇨","🇹🇩","🇹🇫","🇹🇬","🇹🇭","🇹🇯","🇹🇰","🇹🇱","🇹🇲","🇹🇳","🇹🇴","🇹🇷","🇹🇹","🇹🇻","🇹🇼","🇹🇿","🇺🇦","🇺🇬","🇺🇲","🇺🇸","🇺🇾","🇺🇿","🇻🇦","🇻🇨","🇻🇪","🇻🇬","🇻🇮","🇻🇳","🇻🇺","🇼🇫","🇼🇸","🇽🇰","🇾🇪","🇾🇹","🇿🇦","🇿🇲","🇿🇼"]');
 pref('services.sync.prefs.sync.zen.workspaces.icons', true);
 pref('services.sync.engine.workspaces', false);
+pref('services.sync.engine.contextualidentities', true);
 
 // Zen Watermark
 pref('zen.watermark.enabled', true, sticky);
diff --git a/src/browser/base/content/ZenStartup.mjs b/src/browser/base/content/ZenStartup.mjs
index b96e421c6..89761c515 100644
--- a/src/browser/base/content/ZenStartup.mjs
+++ b/src/browser/base/content/ZenStartup.mjs
@@ -35,6 +35,11 @@
         // Disable smooth scroll
         gBrowser.tabContainer.arrowScrollbox.smoothScroll = false;
 
+        // register contextual identity engine
+        if (!Weave.Service.engineManager.get('contextualidentities')) {
+          Weave.Service.engineManager.register(ZenContextualIdentityEngine);
+        }
+
         ZenWorkspaces.init();
         gZenUIManager.init();
         gZenVerticalTabsManager.init();
diff --git a/src/browser/base/content/zen-assets.inc.xhtml b/src/browser/base/content/zen-assets.inc.xhtml
index 74d0d6af7..1df615ad1 100644
--- a/src/browser/base/content/zen-assets.inc.xhtml
+++ b/src/browser/base/content/zen-assets.inc.xhtml
@@ -34,5 +34,6 @@
 <script src="chrome://browser/content/zen-components/ZenWorkspaces.mjs" />
 <script src="chrome://browser/content/zen-components/ZenWorkspacesStorage.mjs" />
 <script src="chrome://browser/content/zen-components/ZenWorkspacesSync.mjs" />
+<script src="chrome://browser/content/zen-components/ZenContextualIdentitiesSync.mjs" />
 <script src="chrome://browser/content/zen-components/ZenViewSplitter.mjs"/>
 <script src="chrome://browser/content/zen-components/ZenProfileDialogUI.mjs" />
diff --git a/src/browser/base/content/zen-assets.jar.inc.mn b/src/browser/base/content/zen-assets.jar.inc.mn
index e8525521d..a07fb4f7d 100644
--- a/src/browser/base/content/zen-assets.jar.inc.mn
+++ b/src/browser/base/content/zen-assets.jar.inc.mn
@@ -10,6 +10,7 @@
         content/browser/zen-components/ZenWorkspaces.mjs        (content/zen-components/src/ZenWorkspaces.mjs)
         content/browser/zen-components/ZenWorkspacesStorage.mjs (content/zen-components/src/ZenWorkspacesStorage.mjs)
         content/browser/zen-components/ZenWorkspacesSync.mjs    (content/zen-components/src/ZenWorkspacesSync.mjs)
+        content/browser/zen-components/ZenContextualIdentitiesSync.mjs    (content/zen-components/src/ZenContextualIdentitiesSync.mjs)
         content/browser/zen-components/ZenSidebarManager.mjs    (content/zen-components/src/ZenSidebarManager.mjs)
         content/browser/zen-components/ZenProfileDialogUI.mjs   (content/zen-components/src/ZenProfileDialogUI.mjs)
         content/browser/zen-components/ZenKeyboardShortcuts.mjs (content/zen-components/src/ZenKeyboardShortcuts.mjs)
diff --git a/src/browser/components/preferences/zen-settings.js b/src/browser/components/preferences/zen-settings.js
index 1ca89df7a..614430145 100644
--- a/src/browser/components/preferences/zen-settings.js
+++ b/src/browser/components/preferences/zen-settings.js
@@ -1076,4 +1076,9 @@ Preferences.addAll([
     type: 'bool',
     default: true,
   },
+  {
+    id: 'services.sync.engine.contextualidentities',
+    type: 'bool',
+    default: true,
+  },
 ]);
diff --git a/src/toolkit/components/contextualidentity/ContextualIdentityService-sys-mjs.patch b/src/toolkit/components/contextualidentity/ContextualIdentityService-sys-mjs.patch
new file mode 100644
index 000000000..4f52f94e4
--- /dev/null
+++ b/src/toolkit/components/contextualidentity/ContextualIdentityService-sys-mjs.patch
@@ -0,0 +1,53 @@
+diff --git a/toolkit/components/contextualidentity/ContextualIdentityService.sys.mjs b/toolkit/components/contextualidentity/ContextualIdentityService.sys.mjs
+index 32f3577c93709a694d1f723acccccad87aa1e5f9..ecd836c9a054cfddbb8c6462a8e8dd2f8e90b4e9 100644
+--- a/toolkit/components/contextualidentity/ContextualIdentityService.sys.mjs
++++ b/toolkit/components/contextualidentity/ContextualIdentityService.sys.mjs
+@@ -713,6 +713,48 @@ _ContextualIdentityService.prototype = {
+ 
+     return data;
+   },
++
++  createWithId (userContextId, name, icon, color) {
++    this.ensureDataReady();
++
++    if (this._identities.some(identity => identity.userContextId === userContextId)) {
++      throw new Error(`Contextual identity with userContextId ${userContextId} already exists.`);
++    }
++
++    if (userContextId >= MAX_USER_CONTEXT_ID) {
++      throw new Error(
++          `Unable to create a new userContext with id '${userContextId}'`
++      );
++    }
++
++    if (!name.trim()) {
++      throw new Error(
++          "Contextual identity names cannot contain only whitespace."
++      );
++    }
++
++    let identity = {
++      userContextId,
++      public: true,
++      icon,
++      color,
++      name,
++    };
++
++    if (userContextId > this._lastUserContextId && userContextId < MAX_USER_CONTEXT_ID) {
++      this._lastUserContextId = userContextId;
++    }
++
++    this._identities.push(identity);
++    this.saveSoon();
++    Services.obs.notifyObservers(
++        this.getIdentityObserverOutput(identity),
++        "contextual-identity-created"
++    );
++
++    return Cu.cloneInto(identity, {});
++  },
++
+ };
+ 
+ let path = PathUtils.join(