gh-14044: Implement Space Routing (gh-13981)

Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>
2026-06-13 15:03:41 +00:00 · 2026-06-06 14:11:42 +02:00
parent b1be664f4d
commit 880d61df16
32 changed files with 2475 additions and 77 deletions
--- a/crowdin.yml
+++ b/crowdin.yml
@@ -22,3 +22,5 @@ files:
    translation: browser/browser/zen-folders.ftl
  - source: en-US/browser/browser/zen-boosts.ftl
    translation: browser/browser/zen-boosts.ftl
+  - source: en-US/browser/browser/zen-space-routing.ftl
+    translation: browser/browser/zen-space-routing.ftl
--- a/locales/en-US/browser/browser/zen-space-routing.ftl
+++ b/locales/en-US/browser/browser/zen-space-routing.ftl
@@ -0,0 +1,25 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+zen-space-routing-settings =
+    .label = Space Routing Settings
+zen-space-routing-rulepanel-placeholder = Routes let you choose where specific sites open inside Zen. For example, you can route YouTube links to always open inside your Personal space.
+zen-space-routing-dialog-title = Space Routing Settings
+zen-space-routing-external-default = Default route for external links
+zen-space-routing-new-route = New Route
+zen-space-routing-open-in-space = Open in Space
+zen-space-routing-most-recent-space = Most recent Space
+zen-space-routing-close-button = 
+    .aria-label = Close
+    .tooltiptext = Close
+
+zen-space-routing-contains =
+    .label = Contains
+zen-space-routing-equal-to =
+    .label = Is Equal To
+zen-space-routing-regex =
+    .label = RegEx
+
+zen-space-routing-open-in = Open In
+zen-space-routing-url = URL
--- a/src/browser/base/content/zen-assets.jar.inc.mn
+++ b/src/browser/base/content/zen-assets.jar.inc.mn
@@ -20,3 +20,4 @@
 #include ../../../zen/fonts/jar.inc.mn
 #include ../../../zen/boosts/jar.inc.mn
 #include ../../../zen/live-folders/jar.inc.mn
+#include ../../../zen/space-routing/jar.inc.mn
--- a/src/browser/base/content/zen-commands.inc.xhtml
+++ b/src/browser/base/content/zen-commands.inc.xhtml
@@ -41,6 +41,7 @@
  <command id="cmd_zenCtxDeleteWorkspace" />
  <command id="cmd_zenUnloadWorkspace" />
  <command id="cmd_zenUnloadAllOtherWorkspace" />
+  <command id="cmd_zenOpenSpaceRoutingSettings" />
  <command id="cmd_zenChangeWorkspaceName" />
  <command id="cmd_zenChangeWorkspaceIcon" />
  <command id="cmd_zenReorderWorkspaces" />
--- a/src/browser/base/content/zen-locales.inc.xhtml
+++ b/src/browser/base/content/zen-locales.inc.xhtml
@@ -11,4 +11,5 @@
 <link rel="localization" href="browser/zen-folders.ftl"/>
 <link rel="localization" href="browser/zen-boosts.ftl"/>
 <link rel="localization" href="browser/zen-live-folders.ftl"/>
+<link rel="localization" href="browser/zen-space-routing.ftl"/>
 </linkset>
--- a/src/browser/base/content/zen-panels/popups.inc
+++ b/src/browser/base/content/zen-panels/popups.inc
@@ -30,6 +30,7 @@
  <menuitem id="context_zenReorderWorkspaces" data-l10n-id="zen-workspaces-panel-context-reorder" command="cmd_zenReorderWorkspaces"/>
  <menuitem id="context_zenUnloadWorkspace" data-l10n-id="zen-workspaces-panel-unload" command="cmd_zenUnloadWorkspace"/>
  <menuitem id="context_zenUnloadAllOtherWorkspace" data-l10n-id="zen-workspaces-panel-unload-others" command="cmd_zenUnloadAllOtherWorkspace"/>
+  <menuitem id="context_zenSpaceRoutingSettings" data-l10n-id="zen-space-routing-settings" command="cmd_zenOpenSpaceRoutingSettings"/>
  <menuseparator/>
  <menuitem data-l10n-id="zen-panel-ui-workspaces-create" command="cmd_zenOpenWorkspaceCreation"/>
  <menuitem id="context_zenDeleteWorkspace" data-l10n-id="zen-workspaces-panel-context-delete" command="cmd_zenCtxDeleteWorkspace"/>
--- a/src/browser/components/tabbrowser/content/tabbrowser-js.patch
+++ b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tabbrowser.js b/browser/components/tabbrowser/content/tabbrowser.js
-index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88f4eec282 100644
+index 43fb79a3060e20f671ae6ffc26350c7abf497702..2da16e06541438ece4a3ae3a1663a1559780fe22 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
@@ -502,6 +502,7 @@
@@ -264,23 +264,32 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
               focusUrlBar: true,
             });
             resolve(this.selectedBrowser);
-@@ -3285,6 +3369,9 @@
+@@ -3285,6 +3369,10 @@
         schemelessInput,
         hasValidUserGestureActivation = false,
         textDirectiveUserActivation = false,
 +        _forZenEmptyTab,
 +        essential,
 +        zenWorkspaceId,
+        skipRoute = false,
       } = {}
     ) {
       // all callers of addTab that pass a params object need to pass
-@@ -3295,10 +3382,17 @@
+@@ -3295,10 +3383,25 @@
         );
       }
 
+      const beforeRouteResult = window.gZenSpaceRoutingManager.onBeforeAddTab(uriString, { skipRoute, pinned, tabGroup, fromExternal }, window);
+      if (beforeRouteResult.shouldEarlyExit) {
+        return null;
+      }
+
 +      let hasZenDefaultUserContextId = false;
 +      let zenForcedWorkspaceId = undefined;
-+      if (typeof gZenWorkspaces !== "undefined" && !_forZenEmptyTab) {
+      if (beforeRouteResult.userContextId) {
+        userContextId = beforeRouteResult.userContextId;
+        hasZenDefaultUserContextId = true;
+      } else if (typeof gZenWorkspaces !== "undefined" && !_forZenEmptyTab) {
 +        [userContextId, hasZenDefaultUserContextId, zenForcedWorkspaceId] = gZenWorkspaces.getContextIdIfNeeded(userContextId, fromExternal, triggeringPrincipal);
 +      }
 +
@@ -292,7 +301,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // If we're opening a foreground tab, set the owner by default.
       ownerTab ??= inBackground ? null : this.selectedTab;
 
-@@ -3306,6 +3400,7 @@
+@@ -3306,6 +3409,7 @@
       if (this.selectedTab.owner) {
         this.selectedTab.owner = null;
       }
@@ -300,7 +309,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       // Find the tab that opened this one, if any. This is used for
       // determining positioning, and inherited attributes such as the
-@@ -3358,6 +3453,22 @@
+@@ -3358,6 +3462,22 @@
           noInitialLabel,
           skipBackgroundNotify,
         });
@@ -323,7 +332,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         if (insertTab) {
           // Insert the tab into the tab container in the correct position.
           this.#insertTabAtIndex(t, {
-@@ -3366,6 +3477,7 @@
+@@ -3366,6 +3486,7 @@
             ownerTab,
             openerTab,
             pinned,
@@ -331,7 +340,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
             bulkOrderedOpen,
             tabGroup: tabGroup ?? openerTab?.group,
           });
-@@ -3384,6 +3496,7 @@
+@@ -3384,6 +3505,7 @@
           openWindowInfo,
           skipLoad,
           triggeringRemoteType,
@@ -339,7 +348,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         }));
 
         if (focusUrlBar) {
-@@ -3508,6 +3621,12 @@
+@@ -3508,6 +3630,12 @@
         }
       }
 
@@ -352,7 +361,17 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // Additionally send pinned tab events
       if (pinned) {
         this.#notifyPinnedStatus(t);
-@@ -3750,6 +3869,7 @@
+@@ -3518,6 +3646,9 @@
+       if (!inBackground) {
+         this.selectedTab = t;
+       }
+
+      window.gZenSpaceRoutingManager.onAfterAddTab(uriString, t, { skipRoute: skipRoute || _forZenEmptyTab, fromExternal, pinned, tabGroup }, window, beforeRouteResult);
+
+       return t;
+     }
+ 
+@@ -3750,6 +3881,7 @@
         isAdoptingGroup = false,
         isUserTriggered = false,
         telemetryUserCreateSource = "unknown",
@@ -360,7 +379,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       } = {}
     ) {
       if (
-@@ -3760,9 +3880,6 @@
+@@ -3760,9 +3892,6 @@
             !this.isSplitViewWrapper(tabOrSplitView)
         )
       ) {
@@ -370,7 +389,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       }
 
       if (!color) {
-@@ -3783,9 +3900,14 @@
+@@ -3783,9 +3912,14 @@
         label,
         isAdoptingGroup
       );
@@ -387,7 +406,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       );
       group.addTabs(tabsAndSplitViews);
 
-@@ -3906,7 +4028,7 @@
+@@ -3906,7 +4040,7 @@
       }
 
       this.#handleTabMove(tab, () =>
@@ -396,7 +415,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       );
     }
 
-@@ -3990,6 +4112,7 @@
+@@ -3990,6 +4124,7 @@
         color: group.color,
         insertBefore: newTabs[0],
         isAdoptingGroup: true,
@@ -404,7 +423,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       });
     }
 
-@@ -4200,6 +4323,7 @@
+@@ -4200,6 +4335,7 @@
         openWindowInfo,
         skipLoad,
         triggeringRemoteType,
@@ -412,7 +431,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       }
     ) {
       // If we don't have a preferred remote type (or it is `NOT_REMOTE`), and
-@@ -4269,6 +4393,7 @@
+@@ -4269,6 +4405,7 @@
           openWindowInfo,
           name,
           skipLoad,
@@ -420,7 +439,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         });
       }
 
-@@ -4482,9 +4607,9 @@
+@@ -4482,9 +4619,9 @@
         }
 
         // Add a new tab if needed.
@@ -432,7 +451,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
           let url = "about:blank";
           if (tabData.entries?.length) {
-@@ -4521,8 +4646,10 @@
+@@ -4521,8 +4658,10 @@
             insertTab: false,
             skipLoad: true,
             preferredRemoteType,
@@ -444,7 +463,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
           if (select) {
             tabToSelect = tab;
           }
-@@ -4544,7 +4671,8 @@
+@@ -4544,7 +4683,8 @@
           this.pinTab(tab);
           // Then ensure all the tab open/pinning information is sent.
           this._fireTabOpen(tab, {});
@@ -454,7 +473,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
           let { groupId } = tabData;
           const tabGroup = tabGroupWorkingData.get(groupId);
           // if a tab refers to a tab group we don't know, skip any group
-@@ -4564,7 +4692,10 @@
+@@ -4564,7 +4704,10 @@
                 tabGroup.stateData.id,
                 tabGroup.stateData.color,
                 tabGroup.stateData.collapsed,
@@ -466,7 +485,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
               );
               tabsFragment.appendChild(tabGroup.node);
             }
-@@ -4619,9 +4750,21 @@
+@@ -4619,9 +4762,21 @@
       // to remove the old selected tab.
       if (tabToSelect) {
         let leftoverTab = this.selectedTab;
@@ -488,7 +507,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       if (tabs.length > 1 || !tabs[0].selected) {
         this._updateTabsAfterInsert();
-@@ -4812,11 +4955,14 @@
+@@ -4812,11 +4967,14 @@
       if (ownerTab) {
         tab.owner = ownerTab;
       }
@@ -504,7 +523,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         if (
           !bulkOrderedOpen &&
           ((openerTab &&
-@@ -4828,7 +4974,7 @@
+@@ -4828,7 +4986,7 @@
           let lastRelatedTab =
             openerTab && this._lastRelatedTabMap.get(openerTab);
           let previousTab = lastRelatedTab || openerTab || this.selectedTab;
@@ -513,7 +532,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
             tabGroup = previousTab.group;
           }
           if (
-@@ -4844,7 +4990,7 @@
+@@ -4844,7 +5002,7 @@
                 previousTab.splitview
               ) + 1;
           } else if (previousTab.visible) {
@@ -522,7 +541,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
           } else if (previousTab == FirefoxViewHandler.tab) {
             elementIndex = 0;
           }
-@@ -4872,14 +5018,14 @@
+@@ -4872,14 +5030,14 @@
       }
       // Ensure index is within bounds.
       if (tab.pinned) {
@@ -541,7 +560,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       if (pinned && !itemAfter?.pinned) {
         itemAfter = null;
-@@ -4896,7 +5042,7 @@
+@@ -4896,7 +5054,7 @@
 
       this.tabContainer._invalidateCachedTabs();
 
@@ -550,7 +569,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         if (
           (this.isTab(itemAfter) && itemAfter.group == tabGroup) ||
           this.isSplitViewWrapper(itemAfter)
-@@ -4927,7 +5073,11 @@
+@@ -4927,7 +5085,11 @@
         const tabContainer = pinned
           ? this.tabContainer.pinnedTabsContainer
           : this.tabContainer;
@@ -562,7 +581,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       }
 
       if (tab.group?.collapsed) {
-@@ -4942,6 +5092,7 @@
+@@ -4942,6 +5104,7 @@
       if (pinned) {
         this._updateTabBarForPinnedTabs();
       }
@@ -570,7 +589,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       TabBarVisibility.update();
     }
-@@ -5490,6 +5641,7 @@
+@@ -5490,6 +5653,7 @@
         telemetrySource,
       } = {}
     ) {
@@ -578,7 +597,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // When 'closeWindowWithLastTab' pref is enabled, closing all tabs
       // can be considered equivalent to closing the window.
       if (
-@@ -5579,6 +5731,7 @@
+@@ -5579,6 +5743,7 @@
         if (lastToClose) {
           this.removeTab(lastToClose, aParams);
         }
@@ -586,7 +605,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       } catch (e) {
         console.error(e);
       }
-@@ -5624,6 +5777,14 @@
+@@ -5624,6 +5789,14 @@
         return;
       }
 
@@ -601,7 +620,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       let isVisibleTab = aTab.visible;
       // We have to sample the tab width now, since _beginRemoveTab might
       // end up modifying the DOM in such a way that aTab gets a new
-@@ -5631,6 +5792,9 @@
+@@ -5631,6 +5804,9 @@
       // state).
       let tabWidth = window.windowUtils.getBoundsWithoutFlushing(aTab).width;
       let isLastTab = this.#isLastTabInWindow(aTab);
@@ -611,7 +630,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       if (
         !this._beginRemoveTab(aTab, {
           closeWindowFastpath: true,
-@@ -5642,13 +5806,14 @@
+@@ -5642,13 +5818,14 @@
           telemetrySource,
         })
       ) {
@@ -627,7 +646,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       let lockTabSizing =
         !this.tabContainer.verticalMode &&
         !aTab.pinned &&
-@@ -5679,7 +5844,13 @@
+@@ -5679,7 +5856,13 @@
         // We're not animating, so we can cancel the animation stopwatch.
         Glean.browserTabclose.timeAnim.cancel(aTab._closeTimeAnimTimerId);
         aTab._closeTimeAnimTimerId = null;
@@ -642,7 +661,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         return;
       }
 
-@@ -5813,7 +5984,7 @@
+@@ -5813,7 +5996,7 @@
           closeWindowWithLastTab != null
             ? closeWindowWithLastTab
             : !window.toolbar.visible ||
@@ -651,7 +670,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
         if (closeWindow) {
           // We've already called beforeunload on all the relevant tabs if we get here,
-@@ -5837,6 +6008,7 @@
+@@ -5837,6 +6020,7 @@
 
         newTab = true;
       }
@@ -659,7 +678,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       aTab._endRemoveArgs = [closeWindow, newTab];
 
       // swapBrowsersAndCloseOther will take care of closing the window without animation.
-@@ -5877,13 +6049,7 @@
+@@ -5877,13 +6061,7 @@
       aTab._mouseleave();
 
       if (newTab) {
@@ -674,7 +693,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       } else {
         TabBarVisibility.update();
       }
-@@ -6016,6 +6182,7 @@
+@@ -6016,6 +6194,7 @@
         this.tabs[i]._tPos = i;
       }
 
@@ -682,7 +701,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       if (!this._windowIsClosing) {
         // update tab close buttons state
         this.tabContainer._updateCloseButtons();
-@@ -6201,6 +6368,7 @@
+@@ -6201,6 +6380,7 @@
         memory_after: await getTotalMemoryUsage(),
         time_to_unload_in_ms: timeElapsed,
       });
@@ -690,7 +709,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
     }
 
     /**
-@@ -6246,6 +6414,7 @@
+@@ -6246,6 +6426,7 @@
       }
 
       let excludeTabs = new Set(aExcludeTabs);
@@ -698,7 +717,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       // If this tab has a successor, it should be selectable, since
       // hiding or closing a tab removes that tab as a successor.
-@@ -6258,15 +6427,22 @@
+@@ -6258,15 +6439,22 @@
         !excludeTabs.has(aTab.owner) &&
         Services.prefs.getBoolPref("browser.tabs.selectOwnerOnClose")
       ) {
@@ -723,7 +742,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       let tab = this.tabContainer.findNextTab(aTab, {
         direction: 1,
         filter: _tab => remainingTabs.includes(_tab),
-@@ -6280,7 +6456,7 @@
+@@ -6280,7 +6468,7 @@
       }
 
       if (tab) {
@@ -732,7 +751,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       }
 
       // If no qualifying visible tab was found, see if there is a tab in
-@@ -6301,7 +6477,7 @@
+@@ -6301,7 +6489,7 @@
         });
       }
 
@@ -741,7 +760,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
     }
 
     _blurTab(aTab) {
-@@ -6312,7 +6488,7 @@
+@@ -6312,7 +6500,7 @@
      * @returns {boolean}
      *   False if swapping isn't permitted, true otherwise.
      */
@@ -750,7 +769,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // Do not allow transfering a private tab to a non-private window
       // and vice versa.
       if (
-@@ -6366,6 +6542,7 @@
+@@ -6366,6 +6554,7 @@
       // fire the beforeunload event in the process.  Close the other
       // window if this was its last tab.
       if (
@@ -758,7 +777,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         !remoteBrowser._beginRemoveTab(aOtherTab, {
           adoptedByTab: aOurTab,
           closeWindowWithLastTab: true,
-@@ -6377,7 +6554,7 @@
+@@ -6377,7 +6566,7 @@
       // If this is the last tab of the window, hide the window
       // immediately without animation before the docshell swap, to avoid
       // about:blank being painted.
@@ -767,7 +786,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       if (closeWindow) {
         let win = aOtherTab.ownerGlobal;
         win.windowUtils.suppressAnimation(true);
-@@ -6511,11 +6688,13 @@
+@@ -6511,11 +6700,13 @@
       }
 
       // Finish tearing down the tab that's going away.
@@ -781,7 +800,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       this.setTabTitle(aOurTab);
 
-@@ -6717,10 +6896,10 @@
+@@ -6717,10 +6908,10 @@
       SessionStore.deleteCustomTabValue(aTab, "hiddenBy");
     }
 
@@ -794,7 +813,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         aTab.selected ||
         aTab.closing ||
         // Tabs that are sharing the screen, microphone or camera cannot be hidden.
-@@ -6780,7 +6959,8 @@
+@@ -6780,7 +6971,8 @@
      * @param {object} [aOptions={}]
      *   Key-value pairs that will be serialized into the features string.
      */
@@ -804,7 +823,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       if (this.tabs.length == 1) {
         return null;
       }
-@@ -6797,7 +6977,7 @@
+@@ -6797,7 +6989,7 @@
       // tell a new window to take the "dropped" tab
       let args = Cc["@mozilla.org/array;1"].createInstance(Ci.nsIMutableArray);
       args.appendElement(aTab.splitview ?? aTab);
@@ -813,7 +832,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         private: PrivateBrowsingUtils.isWindowPrivate(window),
         features: Object.entries(aOptions)
           .map(([key, value]) => `${key}=${value}`)
-@@ -6805,6 +6985,8 @@
+@@ -6805,6 +6997,8 @@
         openerWindow: window,
         args,
       });
@@ -822,7 +841,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
     }
 
     /**
-@@ -6917,7 +7099,7 @@
+@@ -6917,7 +7111,7 @@
      *   `true` if element is a `<tab-group>`
      */
     isTabGroup(element) {
@@ -831,7 +850,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
     }
 
     /**
-@@ -7002,8 +7184,8 @@
+@@ -7002,8 +7196,8 @@
       }
 
       // Don't allow mixing pinned and unpinned tabs.
@@ -842,7 +861,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       } else {
         tabIndex = Math.max(tabIndex, this.pinnedTabCount);
       }
-@@ -7049,8 +7231,8 @@
+@@ -7049,8 +7243,8 @@
       this.#handleTabMove(
         element,
         () => {
@@ -853,7 +872,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
             neighbor = neighbor.group;
           }
           if (neighbor?.splitview) {
-@@ -7061,6 +7243,12 @@
+@@ -7061,6 +7255,12 @@
               return;
             }
           }
@@ -866,7 +885,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
           if (movingForwards && neighbor) {
             neighbor.after(element);
-@@ -7119,23 +7307,31 @@
+@@ -7119,23 +7319,31 @@
     #moveTabNextTo(element, targetElement, moveBefore = false, metricsContext) {
       if (this.isTabGroupLabel(targetElement)) {
         targetElement = targetElement.group;
@@ -904,7 +923,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       } else if (!element.pinned && targetElement && targetElement.pinned) {
         // If the caller asks to move an unpinned element next to a pinned
         // tab, move the unpinned element to be the first unpinned element
-@@ -7148,12 +7344,35 @@
+@@ -7148,12 +7356,35 @@
         //    move the tab group right before the first unpinned tab.
         // 4. Moving a tab group and the first unpinned tab is grouped:
         //    move the tab group right before the first unpinned tab's tab group.
@@ -941,7 +960,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       // We want to include the splitview wrapper if it's the targetElement, but
       // not in the case where we want to reverse tabs within the same splitview.
-@@ -7162,6 +7381,7 @@
+@@ -7162,6 +7393,7 @@
       }
 
       let getContainer = () =>
@@ -949,7 +968,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         element.pinned
           ? this.tabContainer.pinnedTabsContainer
           : this.tabContainer;
-@@ -7170,11 +7390,15 @@
+@@ -7170,11 +7402,15 @@
         element,
         () => {
           if (moveBefore) {
@@ -966,7 +985,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
           }
         },
         metricsContext
-@@ -7248,11 +7472,15 @@
+@@ -7248,11 +7484,15 @@
      * @param {TabMetricsContext} [metricsContext]
      */
     moveTabToExistingGroup(aTab, aGroup, metricsContext) {
@@ -985,7 +1004,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       }
       if (aTab.group && aTab.group.id === aGroup.id) {
         return;
-@@ -7324,6 +7552,7 @@
+@@ -7324,6 +7564,7 @@
 
       let state = {
         tabIndex: tab._tPos,
@@ -993,7 +1012,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       };
       if (tab.visible) {
         state.elementIndex = tab.elementIndex;
-@@ -7355,7 +7584,7 @@
+@@ -7355,7 +7596,7 @@
       let changedSplitView =
         previousTabState.splitViewId != currentTabState.splitViewId;
 
@@ -1002,7 +1021,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         tab.dispatchEvent(
           new CustomEvent("TabMove", {
             bubbles: true,
-@@ -7402,6 +7631,10 @@
+@@ -7402,6 +7643,10 @@
 
       moveActionCallback();
 
@@ -1013,7 +1032,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // Clear tabs cache after moving nodes because the order of tabs may have
       // changed.
       this.tabContainer._invalidateCachedTabs();
-@@ -7452,7 +7685,22 @@
+@@ -7452,7 +7697,22 @@
      * @returns {object}
      *    The new tab in the current window, null if the tab couldn't be adopted.
      */
@@ -1037,7 +1056,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       // Swap the dropped tab with a new one we create and then close
       // it in the other window (making it seem to have moved between
       // windows). We also ensure that the tab we create to swap into has
-@@ -7495,6 +7743,8 @@
+@@ -7495,6 +7755,8 @@
       }
       params.skipLoad = true;
       let newTab = this.addWebTab("about:blank", params);
@@ -1046,7 +1065,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
       aTab.container.tabDragAndDrop.finishAnimateTabMove();
 
-@@ -8205,7 +8455,7 @@
+@@ -8205,7 +8467,7 @@
         // preventDefault(). It will still raise the window if appropriate.
         return;
       }
@@ -1055,7 +1074,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       window.focus();
       aEvent.preventDefault();
     }
-@@ -8222,7 +8472,6 @@
+@@ -8222,7 +8484,6 @@
 
     on_TabGroupCollapse(aEvent) {
       aEvent.target.tabs.forEach(tab => {
@@ -1063,7 +1082,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
       });
     }
 
-@@ -8556,7 +8805,9 @@
+@@ -8556,7 +8817,9 @@
 
         let filter = this._tabFilters.get(tab);
         if (filter) {
@@ -1073,7 +1092,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
 
           let listener = this._tabListeners.get(tab);
           if (listener) {
-@@ -9359,6 +9610,7 @@
+@@ -9359,6 +9622,7 @@
             aWebProgress.isTopLevel
           ) {
             this.mTab.setAttribute("busy", "true");
@@ -1081,7 +1100,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
             gBrowser._tabAttrModified(this.mTab, ["busy"]);
             this.mTab._notselectedsinceload = !this.mTab.selected;
           }
-@@ -9439,6 +9691,7 @@
+@@ -9439,6 +9703,7 @@
         // known defaults. Note we use the original URL since about:newtab
         // redirects to a prerendered page.
         const shouldRemoveFavicon =
@@ -1089,7 +1108,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
           !this.mBrowser.mIconURL &&
           !ignoreBlank &&
           !(originalLocation.spec in FAVICON_DEFAULTS);
-@@ -9613,13 +9866,6 @@
+@@ -9613,13 +9878,6 @@
             this.mBrowser.originalURI = aRequest.originalURI;
           }
 
@@ -1103,7 +1122,7 @@ index 43fb79a3060e20f671ae6ffc26350c7abf497702..146b1559b8430773bd4ec173a8f4fe88
         }
 
         let userContextId = this.mBrowser.getAttribute("usercontextid") || 0;
-@@ -10507,7 +10753,8 @@ var TabContextMenu = {
+@@ -10507,7 +10765,8 @@ var TabContextMenu = {
     );
     contextUnpinSelectedTabs.hidden =
       !this.contextTab.pinned || !this.multiselected;
--- a/src/browser/themes/shared/zen-icons/icons.css
+++ b/src/browser/themes/shared/zen-icons/icons.css
@@ -51,7 +51,8 @@
 }

 #PanelUI-zen-gradient-generator-color-remove,
-#zen-gradient-generator-color-remove {
+#zen-gradient-generator-color-remove,
+.sr-remove {
  list-style-image: url("unpin.svg") !important;
 }

@@ -134,6 +135,10 @@
  list-style-image: url("arrow-right.svg");
 }

+.sr-open-in-icon {
+  list-style-image: url("arrow-corner-down-right.svg");
+}
+
 #PanelUI-menu-button,
 #appMenu-more-button2,
 .zen-workspaces-actions,
@@ -1006,7 +1011,8 @@
  }
 }

-#zen-copy-url-button image {
+#zen-copy-url-button image,
+.sr-url-icon {
  list-style-image: url("link.svg");
  fill-opacity: 0.65;
 }
@@ -1090,3 +1096,7 @@
 #zen-boost-load {
  list-style-image: url("open.svg");
 }
+
+.sr-airplane {
+  list-style-image: url("selectable/airplane.svg");
+}
--- a/src/browser/themes/shared/zen-icons/jar.inc.mn
+++ b/src/browser/themes/shared/zen-icons/jar.inc.mn
@@ -4,6 +4,7 @@

 #ifdef XP_WIN
 *  skin/classic/browser/zen-icons/algorithm.svg                      (../shared/zen-icons/nucleo/algorithm.svg) 
+*  skin/classic/browser/zen-icons/arrow-corner-down-right.svg                      (../shared/zen-icons/nucleo/arrow-corner-down-right.svg) 
 *  skin/classic/browser/zen-icons/arrow-down.svg                      (../shared/zen-icons/nucleo/arrow-down.svg) 
 *  skin/classic/browser/zen-icons/arrow-left.svg                      (../shared/zen-icons/nucleo/arrow-left.svg) 
 *  skin/classic/browser/zen-icons/arrow-right.svg                      (../shared/zen-icons/nucleo/arrow-right.svg) 
@@ -153,6 +154,7 @@
 #endif
 #ifdef XP_MACOSX
 *  skin/classic/browser/zen-icons/algorithm.svg                      (../shared/zen-icons/nucleo/algorithm.svg) 
+*  skin/classic/browser/zen-icons/arrow-corner-down-right.svg                      (../shared/zen-icons/nucleo/arrow-corner-down-right.svg) 
 *  skin/classic/browser/zen-icons/arrow-down.svg                      (../shared/zen-icons/nucleo/arrow-down.svg) 
 *  skin/classic/browser/zen-icons/arrow-left.svg                      (../shared/zen-icons/nucleo/arrow-left.svg) 
 *  skin/classic/browser/zen-icons/arrow-right.svg                      (../shared/zen-icons/nucleo/arrow-right.svg) 
@@ -302,6 +304,7 @@
 #endif
 #ifdef XP_LINUX
 *  skin/classic/browser/zen-icons/algorithm.svg                      (../shared/zen-icons/nucleo/algorithm.svg) 
+*  skin/classic/browser/zen-icons/arrow-corner-down-right.svg                      (../shared/zen-icons/nucleo/arrow-corner-down-right.svg) 
 *  skin/classic/browser/zen-icons/arrow-down.svg                      (../shared/zen-icons/nucleo/arrow-down.svg) 
 *  skin/classic/browser/zen-icons/arrow-left.svg                      (../shared/zen-icons/nucleo/arrow-left.svg) 
 *  skin/classic/browser/zen-icons/arrow-right.svg                      (../shared/zen-icons/nucleo/arrow-right.svg) 
--- a/src/browser/themes/shared/zen-icons/nucleo/arrow-corner-down-right.svg
+++ b/src/browser/themes/shared/zen-icons/nucleo/arrow-corner-down-right.svg
@@ -0,0 +1,5 @@
+#filter dumbComments emptyLines substitution
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+<svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" fill="context-fill" fill-opacity="context-fill-opacity" viewBox="0 0 18 18"><path d="M2.75 3a.75.75 0 0 1 .75.75v4C3.5 8.44 4.06 9 4.75 9h8.69l-2.97-2.97a.75.75 0 1 1 1.06-1.06l4.25 4.25a.8.8 0 0 1 .118.16q.025.04.044.083a.75.75 0 0 1-.078.715 1 1 0 0 1-.084.102l-4.25 4.25a.75.75 0 0 1-1.06-1.06l2.97-2.97H4.75A2.75 2.75 0 0 1 2 7.75v-4A.75.75 0 0 1 2.75 3"/></svg>
--- a/src/zen/common/ZenPreloadedScripts.js
+++ b/src/zen/common/ZenPreloadedScripts.js
@@ -5,6 +5,11 @@
 // prettier-ignore
 // eslint-disable-next-line no-lone-blocks
 {
+  ChromeUtils.defineESModuleGetters(this, {
+    gZenSpaceRoutingManager:
+      "resource:///modules/zen/spacerouting/ZenSpaceRoutingManager.sys.mjs",
+  });
+
  Services.scriptloader.loadSubScript("chrome://browser/content/zen-components/ZenSpaceBookmarksStorage.js", this);

  let scripts = [
--- a/src/zen/common/styles/zen-panels/dialog.css
+++ b/src/zen/common/styles/zen-panels/dialog.css
@@ -5,10 +5,10 @@
 */
 .dialogBox {
  border-radius: 12px !important;
-  border: 1px solid light-dark(rgba(168, 168, 169, 0.50), var(--zen-dialog-background)) !important;
+  border: 0.5px solid light-dark(rgba(0, 0, 0, 0.4), var(--zen-dialog-background)) !important;
  outline: 1px solid light-dark(transparent, rgba(168, 168, 169, 0.50)) !important;
  box-shadow: 0 10px 8px rgba(0, 0 , 0, 0.15) !important;
-  outline-offset: -1.5px;
+  outline-offset: -2px;

  @media not (prefers-reduced-motion: reduce) {
    animation: zen-dialog-fade-in 0.3s ease-out;
--- a/src/zen/common/zen-sets.js
+++ b/src/zen/common/zen-sets.js
@@ -133,6 +133,10 @@ document.addEventListener(
            gZenWorkspaces.unloadAllOtherWorkspaces();
            break;
          }
+          case "cmd_zenOpenSpaceRoutingSettings": {
+            gZenSpaceRoutingManager.openSpaceRoutingDialog(window);
+            break;
+          }
          case "cmd_zenNewNavigatorUnsynced":
            OpenBrowserWindow({ zenSyncedWindow: false });
            break;
--- a/src/zen/glance/ZenGlanceManager.mjs
+++ b/src/zen/glance/ZenGlanceManager.mjs
@@ -214,6 +214,7 @@ class nsZenGlanceManager extends nsZenDOMOperatedFeature {
      skipAnimation: true,
      ownerTab: currentTab,
      triggeringPrincipal: data.triggeringPrincipal,
+      skipRoute: true,
    };
  }

--- a/src/zen/moz.build
+++ b/src/zen/moz.build
@@ -19,4 +19,5 @@ DIRS += [
    "sessionstore",
    "share",
    "spaces",
+    "space-routing",
 ]
--- a/src/zen/space-routing/ZenSpaceRoutingDialog.mjs
+++ b/src/zen/space-routing/ZenSpaceRoutingDialog.mjs
@@ -0,0 +1,454 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// eslint-disable-next-line no-shadow
+const { gZenSpaceRoutingManager } = ChromeUtils.importESModule(
+  "resource:///modules/zen/spacerouting/ZenSpaceRoutingManager.sys.mjs"
+);
+
+export class nsZenSpaceRoutingDialog {
+  doc = null;
+  editorWindow = null;
+  openerWindow = null;
+
+  static OBSERVERS = ["zen-space-routing-kill"];
+
+  /**
+   * Creates a new Space Routing dialog controller.
+   *
+   * @param {Document} doc - The document object for the dialog window.
+   * @param {Window} editorWindow - The Space Routing dialog window.
+   * @param {Window} openerWindow - The browser window that opened the dialog.
+   */
+  constructor(doc, editorWindow, openerWindow) {
+    this.doc = doc;
+    this.editorWindow = editorWindow;
+    this.openerWindow = openerWindow;
+
+    this.killOtherShareInstances();
+
+    nsZenSpaceRoutingDialog.OBSERVERS.forEach(observe => {
+      Services.obs.addObserver(this, observe);
+    });
+
+    this.init();
+    this.editorWindow.addEventListener("unload", () => this.uninit(), {
+      once: true,
+    });
+  }
+
+  /**
+   * Initializes the boost share instance by setting up event listeners for all UI controls.
+   */
+  init() {
+    this.editorWindow.addEventListener("unload", () => this.handleClose(), {
+      once: true,
+    });
+
+    this.doc
+      .getElementById("sr-close")
+      .addEventListener("click", this.onClosePressed.bind(this));
+    this.doc
+      .getElementById("sr-new-route")
+      .addEventListener("click", this.onNewRoutePressed.bind(this));
+
+    const defaultRouteSelect = this.doc.getElementById(
+      "sr-default-external-open-in"
+    );
+    this.createOpenInList(
+      defaultRouteSelect,
+      gZenSpaceRoutingManager.getDefaultExternalRoute()
+    );
+
+    defaultRouteSelect.addEventListener("command", e =>
+      this.onRouteDefaultExternalChange(e.target.value)
+    );
+
+    this.doc.addEventListener("keydown", event => {
+      if (
+        event.key === "Escape" ||
+        (event.key === "w" && (event.ctrlKey || event.metaKey))
+      ) {
+        this.onClosePressed();
+      }
+    });
+
+    this.initRouteList();
+    this.initialized = true;
+  }
+
+  /**
+   * Initializes the routes list and loads all current routes from the disk
+   */
+  initRouteList() {
+    const allRoutes = gZenSpaceRoutingManager.getAllRoutes();
+    allRoutes.forEach(r => this.createRouteElement(r));
+  }
+
+  /**
+   * Will create a new route and update the route list
+   */
+  onNewRoutePressed() {
+    const newRoute = gZenSpaceRoutingManager.createNewRoute();
+    this.createRouteElement(newRoute);
+  }
+
+  /**
+   * Will remove a route and update the list
+   *
+   * @param {string} routeId - The unique ID of the affected route
+   * @param {string} containerElement - The container element of the route in the list
+   */
+  onRemoveRoutePressed(routeId, containerElement) {
+    gZenSpaceRoutingManager.removeRoute(routeId);
+    containerElement.remove();
+
+    this.updateShowNoRouteText();
+  }
+
+  /**
+   * Will create the rule element content and inject it into the ui
+   *
+   * @param {object} route - The target route
+   * @returns {Element} The created element for the route
+   */
+  createRouteElement(route) {
+    const container = this.doc.getElementById("sr-content");
+
+    const root = this.doc.createXULElement("vbox");
+    root.setAttribute("routeId", route.id);
+    root.className = "sr-rule-container";
+
+    // ---- Top row
+
+    const topRow = this.doc.createXULElement("hbox");
+    topRow.className = "sr-rule-row sr-rule-top";
+
+    const topLabelContainer = this.doc.createXULElement("hbox");
+    topLabelContainer.className = "sr-label-container";
+
+    const urlIcon = this.doc.createXULElement("image");
+    urlIcon.className = "sr-url-icon";
+
+    const urlLabel = this.doc.createXULElement("label");
+    urlLabel.className = "sr-label";
+    urlLabel.setAttribute("data-l10n-id", "zen-space-routing-url");
+
+    topLabelContainer.append(urlIcon, urlLabel);
+
+    // Match type
+
+    const matchTypeMenulist = this.doc.createXULElement("menulist");
+    matchTypeMenulist.className = "select match-type-select";
+
+    const matchTypePopup = this.doc.createXULElement("menupopup");
+    matchTypeMenulist.appendChild(matchTypePopup);
+
+    ["contains", "equal-to", "regex"].forEach(id => {
+      const menuItem = this.doc.createXULElement("menuitem");
+      menuItem.setAttribute("data-l10n-id", `zen-space-routing-${id}`);
+      menuItem.setAttribute("value", id);
+      matchTypePopup.appendChild(menuItem);
+    });
+
+    matchTypeMenulist.value = route.matchType;
+
+    // Input domain
+
+    const input = this.doc.createElement("input");
+    input.className = "input";
+    input.value = route.reference;
+    this.updateInputPlaceholder(route.matchType, input);
+
+    const removeButton = this.doc.createXULElement("button");
+    removeButton.className = "sr-remove";
+
+    topRow.append(topLabelContainer, matchTypeMenulist, input, removeButton);
+
+    // ---- Bottom row
+
+    const bottomRow = this.doc.createXULElement("hbox");
+    bottomRow.className = "sr-rule-row sr-rule-bottom";
+
+    const bottomLabelContainer = this.doc.createXULElement("hbox");
+    bottomLabelContainer.className = "sr-label-container";
+
+    const openInIcon = this.doc.createXULElement("image");
+    openInIcon.className = "sr-open-in-icon";
+
+    const openInLabel = this.doc.createXULElement("label");
+    openInLabel.className = "sr-label";
+    openInLabel.setAttribute("data-l10n-id", "zen-space-routing-open-in");
+
+    bottomLabelContainer.append(openInIcon, openInLabel);
+
+    // Open in
+
+    const openInMenulist = this.doc.createXULElement("menulist");
+    openInMenulist.className = "select open-in-select";
+
+    const openInMenupopup = this.doc.createXULElement("menupopup");
+    openInMenulist.appendChild(openInMenupopup);
+
+    this.createOpenInList(openInMenulist, route.openIn);
+
+    bottomRow.append(bottomLabelContainer, openInMenulist);
+
+    root.append(topRow, bottomRow);
+    container.appendChild(root);
+
+    removeButton.addEventListener("click", () => {
+      this.onRemoveRoutePressed(route.id, root);
+    });
+
+    input.addEventListener("input", e =>
+      this.onRouteReferenceChange(e.target.value, route.id, input)
+    );
+    matchTypeMenulist.addEventListener("command", e =>
+      this.onRouteMatchTypeChange(e.target.value, route.id, input)
+    );
+    openInMenulist.addEventListener("command", e =>
+      this.onRouteOpenInChange(e.target.value, route.id)
+    );
+
+    input.focus();
+
+    this.updateShowNoRouteText();
+
+    return root;
+  }
+
+  /**
+   * Checks if the text for when no routes are
+   * created should be displayed
+   */
+  updateShowNoRouteText() {
+    const container = this.doc.getElementById("sr-content");
+    const noRoutesText = this.doc.getElementById("sr-empty-content");
+
+    // One because of the element itself
+    noRoutesText.style.display =
+      container.children.length == 1 ? "flex" : "none";
+  }
+
+  /**
+   * Callback for when the reference text changes
+   *
+   * @param {string} value - The new value
+   * @param {string} routeId - The ID of the affected route
+   * @param {Element} input - The input element
+   */
+  onRouteReferenceChange(value, routeId, input) {
+    const route = gZenSpaceRoutingManager.getRoute(routeId);
+    route.reference = value;
+
+    this.updateInputPlaceholder(route.matchType, input);
+
+    // Don't update the route if the regex is invalid
+    if (route.matchType == "regex") {
+      if (!this.onCheckRegexValid(input)) {
+        return;
+      }
+    }
+
+    gZenSpaceRoutingManager.updateRoute(route);
+  }
+
+  /**
+   * Callback for when the open in attribute changes
+   *
+   * @param {string} value - The new value
+   * @param {string} routeId - The ID of the affected route
+   */
+  onRouteOpenInChange(value, routeId) {
+    const route = gZenSpaceRoutingManager.getRoute(routeId);
+    route.openIn = value;
+    gZenSpaceRoutingManager.updateRoute(route);
+  }
+
+  /**
+   * Callback for when the route match type changes
+   *
+   * @param {string} value - The new value
+   * @param {string} routeId - The ID of the affected route
+   * @param {Element} input - The text input
+   */
+  onRouteMatchTypeChange(value, routeId, input) {
+    const route = gZenSpaceRoutingManager.getRoute(routeId);
+    route.matchType = value;
+
+    this.updateInputPlaceholder(route.matchType, input);
+
+    // Don't update the route if the regex is invalid
+    if (route.matchType == "regex") {
+      if (!this.onCheckRegexValid(input)) {
+        return;
+      }
+    }
+
+    gZenSpaceRoutingManager.updateRoute(route);
+  }
+
+  /**
+   * Updates the input placeholder based on the
+   * current route match type
+   *
+   * @param {string} matchType - The match type (e.g. "contains", "equal-to", "regex")
+   * @param {Element} input - The input element
+   */
+  updateInputPlaceholder(matchType, input) {
+    switch (matchType) {
+      case "regex":
+        input.placeholder = "zen-browser\\.app";
+        break;
+      default:
+        input.placeholder = "zen-browser.app";
+        break;
+    }
+  }
+
+  /**
+   * Will validate and return the validity of the
+   * regex. Applies a tint to the input if an error occurs.
+   *
+   * @param {Element} input - The input element for the regex
+   * @returns {bool} True if regex is valid
+   */
+  onCheckRegexValid(input) {
+    const reference = input.value;
+
+    // Ignore empty
+    if (reference.trim() == "") {
+      input.classList.remove("invalid");
+      return true;
+    }
+
+    try {
+      new RegExp(reference);
+    } catch (e) {
+      input.classList.add("invalid");
+      return false;
+    }
+    input.classList.remove("invalid");
+    return true;
+  }
+
+  /**
+   * Callback for when the default external route changes
+   *
+   * @param {string} value - The new value
+   */
+  onRouteDefaultExternalChange(value) {
+    gZenSpaceRoutingManager.setDefaultExternalRoute(value);
+  }
+
+  /**
+   * Creates the options list selects
+   *
+   * @param {Element} selectElement - The menulist element
+   * @param {string} value - The initial value
+   */
+  async createOpenInList(selectElement, value) {
+    const popupElement =
+      selectElement.querySelector("menupopup") || selectElement;
+    popupElement.replaceChildren(); // Clear existing
+
+    const [openInSpace, mostRecentSpace] = await this.doc.l10n.formatMessages([
+      "zen-space-routing-open-in-space",
+      "zen-space-routing-most-recent-space",
+    ]);
+
+    const sectionHeader = this.doc.createXULElement("menuitem");
+    sectionHeader.setAttribute("label", openInSpace.value);
+    sectionHeader.setAttribute("disabled", "true");
+    sectionHeader.classList.add("menu-section-header");
+    popupElement.appendChild(sectionHeader);
+
+    let availOptions = [];
+
+    let createXulItem = (text, id, iconPath = null) => {
+      if (text === "sep") {
+        popupElement.appendChild(this.doc.createXULElement("menuseparator"));
+        return;
+      }
+
+      availOptions.push(id || text);
+      const menuItem = this.doc.createXULElement("menuitem");
+      menuItem.setAttribute("label", text);
+      menuItem.setAttribute("value", id || text);
+
+      if (iconPath) {
+        if (iconPath.startsWith("chrome://")) {
+          menuItem.setAttribute("class", "menuitem-iconic");
+          menuItem.setAttribute("image", iconPath);
+        } else {
+          menuItem.setAttribute("label", `${iconPath} ${text}`);
+        }
+      }
+
+      popupElement.appendChild(menuItem);
+    };
+
+    const workspaces = this.openerWindow.gZenWorkspaces.getWorkspaces();
+
+    createXulItem(mostRecentSpace.value, "most-recent-space");
+    createXulItem("sep");
+
+    workspaces.forEach(workspace => {
+      createXulItem(workspace.name, workspace.uuid, workspace.icon);
+    });
+
+    // Check if the workspace still exists, if not use default
+    if (availOptions.includes(value)) {
+      selectElement.value = value;
+    } else {
+      selectElement.value = "most-recent-space";
+    }
+  }
+
+  /**
+   * Uninitializes the boost editor by cleaning up event listeners and observers.
+   */
+  uninit() {
+    nsZenSpaceRoutingDialog.OBSERVERS.forEach(observe => {
+      Services.obs.removeObserver(this, observe);
+    });
+  }
+
+  /**
+   * Kills all other Space Routing dialog instances
+   */
+  killOtherShareInstances() {
+    Services.obs.notifyObservers(null, "zen-space-routing-kill");
+  }
+
+  /**
+   * Observer callback that handles notifications from the observer service.
+   * Closes the control window when a 'zen-space-routing-kill' notification is received.
+   *
+   * @param {object} subject - The subject of the notification.
+   * @param {string} topic - The topic of the notification.
+   */
+  observe(subject, topic) {
+    switch (topic) {
+      case "zen-space-routing-kill":
+        this.editorWindow.close();
+        break;
+    }
+  }
+
+  /**
+   * Callback for when the user presses the close button
+   */
+  onClosePressed() {
+    this.editorWindow.close();
+  }
+
+  /**
+   * Handles the window close event
+   */
+  handleClose() {
+    gZenSpaceRoutingManager.saveRoutes();
+  }
+}
--- a/src/zen/space-routing/ZenSpaceRoutingManager.sys.mjs
+++ b/src/zen/space-routing/ZenSpaceRoutingManager.sys.mjs
@@ -0,0 +1,413 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { JSONFile } from "resource://gre/modules/JSONFile.sys.mjs";
+
+class nsZenSpaceRoutingManager {
+  #file = null;
+  #saveFilename = "zen-space-routing.jsonlz4";
+
+  static SKIP_TYPE = {
+    NONE: "none",
+    SKIPPED_TAB: "skipped_tab",
+    RESTORED_TAB: "restored_tab",
+  };
+
+  constructor() {
+    this.#readFromDisk();
+  }
+
+  /**
+   * Callback that will be executed from tabbrowser.js
+   * This method can be used to stop the tab from being created.
+   *
+   * @param {string} uriString - The URI as a string
+   * @param {object} options - The tab creation options
+   * @param {Window} win - The window which the tab will be added to
+   * @returns {object} Returns an object with { shouldEarlyExit, userContextId, isRouteFound, targetRoute }
+   */
+  onBeforeAddTab(uriString, options, win) {
+    let userContextId = null;
+    let isRouteFound = false;
+    let targetRoute = null;
+
+    if (
+      this.#shouldSkipProcessing(options, win) !=
+      nsZenSpaceRoutingManager.SKIP_TYPE.NONE
+    ) {
+      return {
+        shouldEarlyExit: false,
+        userContextId,
+        isRouteFound,
+        targetRoute,
+      };
+    }
+
+    targetRoute = this.routeUri(uriString, options);
+    switch (targetRoute) {
+      case "most-recent-space":
+        break;
+      default: {
+        const targetWorkspace =
+          win?.gZenWorkspaces?.getWorkspaceFromId(targetRoute);
+
+        if (targetWorkspace) {
+          userContextId = targetWorkspace.containerTabId;
+          isRouteFound = true;
+        }
+      }
+    }
+
+    return { shouldEarlyExit: false, userContextId, isRouteFound, targetRoute };
+  }
+
+  /**
+   * Callback that will be executed from tabbrowser.js
+   *
+   * @param {string} uriString - The URI as a string
+   * @param {Element} newTab - The tab element
+   * @param {object} options - The tab creation options
+   * @param {Window} win - The window which the tab was added to
+   * @param {object} [beforeResult] - The result returned by onBeforeAddTab for
+   *   this tab. When present its precomputed targetRoute is reused instead of
+   *   running routeUri() a second time.
+   */
+  onAfterAddTab(uriString, newTab, options, win, beforeResult) {
+    const targetRoute = beforeResult?.targetRoute;
+    if (!targetRoute) {
+      return;
+    }
+
+    this.#routeToWorkspace(targetRoute, newTab, win);
+  }
+
+  /**
+   * Checks if the tab should be processed or not
+   *
+   * @param {object} options - The tab creation options
+   * @param {Window} win - The owning window
+   * @returns {SKIP_TYPE} The type of skip or null if not skipped
+   */
+  #shouldSkipProcessing(options, win) {
+    if (options.skipRoute || options.pinned || options.tabGroup) {
+      return nsZenSpaceRoutingManager.SKIP_TYPE.SKIPPED_TAB;
+    }
+
+    // addTab() is being called when the session restores.
+    // To avoid automatically routing these tabs,
+    // a check if the restore is already complete is needed
+    if (!win.gZenStartup.isReady) {
+      return nsZenSpaceRoutingManager.SKIP_TYPE.RESTORED_TAB;
+    }
+
+    return nsZenSpaceRoutingManager.SKIP_TYPE.NONE;
+  }
+
+  /**
+   * Will route the given tab to a space if a rule applies
+   *
+   * @param {string} targetRoute - The precomputed route for the tab
+   * @param {Element} newTab - The tab element
+   * @param {Window} win - The window which the tab was added to
+   * @private
+   */
+  async #routeToWorkspace(targetRoute, newTab, win) {
+    try {
+      if (!newTab || !newTab.parentNode) {
+        return;
+      }
+
+      switch (targetRoute) {
+        case "most-recent-space":
+          break;
+
+        default: {
+          const workspaces = win?.gZenWorkspaces;
+          const targetWorkspace = workspaces?.getWorkspaceFromId?.(targetRoute);
+
+          if (targetWorkspace) {
+            workspaces.moveTabToWorkspace(newTab, targetWorkspace.uuid);
+            const mostRecentWindow =
+              Services.wm.getMostRecentWindow("navigator:browser");
+            const isOriginatingWindow = win === mostRecentWindow;
+            if (isOriginatingWindow) {
+              win.gZenWorkspaces.lastSelectedWorkspaceTabs[
+                targetWorkspace.uuid
+              ] = newTab;
+              await win.gZenWorkspaces.changeWorkspace(targetWorkspace);
+            }
+          }
+        }
+      }
+    } catch (err) {
+      console.error("[ZenSpaceRouting]: Error moving tab to workspace:", err);
+    }
+  }
+
+  /**
+   * This will give the id of the workspace this uri will
+   * route to, or "most-recent-space"
+   *
+   * @param {string} uriString - The uri which will be routed
+   * @param {object} options - The tab creation options
+   * @returns {string} Route instructions
+   */
+  routeUri(uriString, options) {
+    const isExternal = options.fromExternal;
+
+    // Go over all routes and return the open type for the first match
+    const allRoutes = this.getAllRoutes();
+    for (const route of allRoutes) {
+      if (this.isRouteMatching(uriString, route)) {
+        return route.openIn;
+      }
+    }
+
+    // If nothing matches and it's an external link,
+    // use the default external route
+    if (isExternal) {
+      return this.getDefaultExternalRoute();
+    }
+
+    // If nothing matches, open in most recent space
+    return "most-recent-space";
+  }
+
+  /**
+   * Checks if a given rule matches a uriString
+   *
+   * @param {string} uriString - The uri
+   * @param {object} route - The route
+   * @returns {boolean} True if the rule matches
+   */
+  isRouteMatching(uriString, route) {
+    if (typeof uriString !== "string" || typeof route?.reference !== "string") {
+      return false;
+    }
+
+    let reference = route.reference.toLowerCase();
+    if (reference.trim() == "") {
+      return false;
+    }
+
+    const uri = uriString.toLowerCase();
+    switch (route.matchType) {
+      case "contains":
+        if (uri.includes(reference)) {
+          return true;
+        }
+        break;
+      case "equal-to":
+        if (this.#normalizeURL(uri) == this.#normalizeURL(reference)) {
+          return true;
+        }
+        break;
+      case "regex": {
+        let unmodifiedReference = route.reference;
+        try {
+          // Use unmodified parameters for the regex test
+          const regex = new RegExp(unmodifiedReference);
+          if (regex.test(uriString)) {
+            return true;
+          }
+        } catch (e) {
+          console.error(
+            "[ZenSpaceRouting] Failed to resolve regular expression:",
+            unmodifiedReference,
+            e
+          );
+        }
+        break;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Will remove any protocol sequences to normalize the url
+   *
+   * @param {string} uriString - The url
+   * @returns {string} The normalized url
+   */
+  #normalizeURL(uriString) {
+    if (!uriString) {
+      return "";
+    }
+    let clean = uriString.trim();
+
+    // Remove protocol sequences with regex
+    clean = clean.replace(/^https?:\/\//i, "");
+    clean = clean.replace(/^www\./i, "");
+
+    // If there is a trailing slash, remove
+    if (clean.endsWith("/")) {
+      clean = clean.slice(0, -1);
+    }
+
+    return clean;
+  }
+
+  /**
+   * Opens the Space Routing editor in a new popup window.
+   *
+   * @param {Window} parentWindow - The parent browser window
+   * @returns {Window|null} The instanced editor window
+   */
+  openSpaceRoutingDialog(parentWindow) {
+    const control = parentWindow.openDialog(
+      "chrome://browser/content/zen-components/windows/zen-space-routing.xhtml",
+      "",
+      "centerscreen,modal,dependent,resizable=no,titlebar=no",
+      { parentWindow }
+    );
+
+    control.focus();
+    return control;
+  }
+
+  /**
+   * @returns {object} Returns a new empty Space Routing route
+   */
+  getEmptyRoute() {
+    return {
+      id: crypto.randomUUID(),
+      reference: "",
+      openIn: "most-recent-space",
+      matchType: "contains",
+    };
+  }
+
+  /**
+   * @returns {Array<object>} A copy of the routes list
+   */
+  getAllRoutes() {
+    if (!this.#file?.data?.routes) {
+      return [];
+    }
+    return structuredClone(this.#file.data.routes);
+  }
+
+  /**
+   * Returns a specific route
+   *
+   * @param {string} id - The ID of the given route
+   * @returns {object|null} The route, or null if no route has the given id
+   */
+  getRoute(id) {
+    const idx = this.#file.data.routes.findIndex(r => r.id === id);
+    if (idx === -1) {
+      return null;
+    }
+    return structuredClone(this.#file.data.routes[idx]);
+  }
+
+  /**
+   * Will update an existing route
+   *
+   * @param {object} route - The updated route
+   */
+  updateRoute(route) {
+    const idx = this.#file.data.routes.findIndex(r => r.id === route.id);
+    if (idx === -1) {
+      return;
+    }
+    this.#file.data.routes[idx] = structuredClone(route);
+  }
+
+  /**
+   * Creates a new route and returns it
+   *
+   * @returns {object} Returns the empty route
+   */
+  createNewRoute() {
+    const newRoute = this.getEmptyRoute();
+    this.#file.data.routes.push(newRoute);
+
+    return structuredClone(newRoute);
+  }
+
+  /**
+   * Removes an existing route with the given id
+   *
+   * @param {string} id - The given id
+   */
+  removeRoute(id) {
+    const objWithIdIndex = this.#file.data.routes.findIndex(r => r.id === id);
+    if (objWithIdIndex === -1) {
+      return;
+    }
+    this.#file.data.routes.splice(objWithIdIndex, 1);
+  }
+
+  /**
+   * @returns {string} Returns the default route type for external links
+   */
+  getDefaultExternalRoute() {
+    return this.#file?.data?.defaultRouteExternal ?? "most-recent-space";
+  }
+
+  /**
+   * @param {string} routeType - Sets the default route type for external links
+   */
+  setDefaultExternalRoute(routeType) {
+    this.#file.data.defaultRouteExternal = routeType;
+  }
+
+  /**
+   * Saves all routes
+   */
+  saveRoutes() {
+    this.#writeToDisk();
+  }
+
+  /**
+   * Writes the Space Routing data back onto the disk.
+   *
+   * @private
+   */
+  #writeToDisk() {
+    this.#file.saveSoon();
+  }
+
+  /**
+   * Reads Space Routing data from disk and decompresses it.
+   *
+   * @returns {Promise<Map>} A promise that resolves to an array of Space Routing rules.
+   * @private
+   */
+  async #readFromDisk() {
+    this.#file = new JSONFile({
+      path: this.#storePath,
+      compression: "lz4",
+
+      dataPostProcessor(data) {
+        if (!data || typeof data !== "object") {
+          data = {};
+        }
+        if (!Array.isArray(data.routes)) {
+          data.routes = [];
+        }
+        if (typeof data.defaultRouteExternal !== "string") {
+          data.defaultRouteExternal = "most-recent-space";
+        }
+        return data;
+      },
+    });
+
+    await this.#file.load();
+  }
+
+  /**
+   * Gets the file path where Space Routing data is stored in the user's profile directory.
+   *
+   * @returns {string} The full path to the Space Routing storage file.
+   * @private
+   */
+  get #storePath() {
+    const profilePath = PathUtils.profileDir;
+    return PathUtils.join(profilePath, this.#saveFilename);
+  }
+}
+
+export const gZenSpaceRoutingManager = new nsZenSpaceRoutingManager();
--- a/src/zen/space-routing/jar.inc.mn
+++ b/src/zen/space-routing/jar.inc.mn
@@ -0,0 +1,9 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+        # Styles
+        content/browser/zen-styles/zen-space-routing.css                          (../../zen/space-routing/zen-space-routing.css)
+
+        # Windows
+*       content/browser/zen-components/windows/zen-space-routing.xhtml            (../../zen/space-routing/zen-space-routing.inc.xhtml)
--- a/src/zen/space-routing/moz.build
+++ b/src/zen/space-routing/moz.build
@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXTRA_JS_MODULES.zen.spacerouting += [
+    "ZenSpaceRoutingDialog.mjs",
+    "ZenSpaceRoutingManager.sys.mjs",
+]
--- a/src/zen/space-routing/zen-space-routing.css
+++ b/src/zen/space-routing/zen-space-routing.css
@@ -0,0 +1,315 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+:root {
+  background: none;
+  appearance: none;
+  border: none;
+  outline: none;
+  color-scheme: light dark;
+
+  --sr-background: light-dark(white, #212223);
+  --select-background-color: light-dark(#eceef0, #3e3f43);
+  --input-background-color: light-dark(#f1f2f4, #2c2d31);
+  --hr-color: light-dark(#cdced4, #313235);
+
+  --sr-width: 510px;
+  --sr-height: 500px;
+
+  --content-padding: 26px;
+  --content-padding-vertical: 16px;
+
+  --text-color: light-dark(#4c4c4c, #dbdcdf);
+  --text-color-secondary: light-dark(#5c5e65, #8b8e98);
+  --text-color-error: light-dark(#9d2222, #d03535);
+
+  --rules-gap: 14px;
+
+  --sr-border-radius: 12px;
+}
+
+.dialog-button-box {
+  /* Remove default dialog buttons */
+  display: none !important;
+}
+
+#zen-space-routing-dialog-container {
+  background-color: var(--sr-background);
+  padding: 0;
+  margin: 24px;
+
+  height: var(--sr-height);
+  max-height: var(--sr-height);
+  min-height: var(--sr-height);
+
+  width: var(--sr-width);
+  max-width: var(--sr-width);
+  min-width: var(--sr-width);
+}
+
+#sr-container {
+  height: var(--sr-height);
+  width: var(--sr-width);
+
+  border-radius: var(--sr-border-radius);
+  overflow: hidden;
+  font-family: system-ui !important;
+
+  position: relative;
+  display: flex;
+}
+
+#sr-empty-content {
+  display: flex;
+  flex-direction: column;
+  text-align: center;
+  gap: 24px;
+
+  position: absolute;
+  left: 84px;
+  right: 84px;
+
+  bottom: 100px;
+  top: 100px;
+  justify-content: center;
+
+  & image {
+    aspect-ratio: 1;
+    height: 75px;
+
+    min-height: 0;
+    max-height: none;
+    max-width: none;
+    min-width: 0;
+
+    color: var(--text-color-secondary);
+    -moz-context-properties: fill, fill-opacity;
+    fill: currentColor;
+    fill-opacity: 0.65;
+  }
+
+  & p {
+    font-weight: bold;
+    font-size: small;
+
+    color: var(--text-color);
+  }
+}
+
+.hr {
+  color: var(--hr-color);
+  padding: 0;
+  margin: 0;
+  margin-left: 32px;
+  margin-right: 32px;
+  border-style: solid;
+  border-width: 0.5px;
+}
+
+h3 {
+  font-size: medium;
+  color: var(--text-color);
+  font-weight: normal;
+}
+
+h4 {
+  font-size: small;
+  color: var(--text-color-secondary);
+}
+
+p {
+  color: var(--text-color);
+}
+
+.select {
+  width: 150px;
+  height: 26px;
+  padding: 4px;
+}
+
+.select,
+.select * {
+  background-color: var(--select-background-color);
+  color: var(--text-color);
+  margin: 0;
+
+  &.match-type-select {
+    width: 100px;
+  }
+  &.open-in-select {
+    width: 165px;
+  }
+}
+
+menulist[image] .menulist-icon,
+menulist[image]::part(icon) {
+  width: 16px;
+  height: 16px;
+  min-width: 16px;
+  min-height: 16px;
+  -moz-context-properties: fill, stroke;
+  fill: currentColor;
+  margin-inline-end: 0;
+  padding-left: 2px;
+}
+
+menulist {
+  -moz-box-align: center;
+}
+
+.sr-rule-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.sr-rule-container {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  margin: 0 24px;
+
+  & p {
+    color: var(--text-color-secondary);
+  }
+}
+
+.sr-rule-bottom {
+  margin-left: 85px;
+}
+
+.input,
+.input * {
+  background-color: var(--input-background-color);
+  color: var(--text-color);
+  margin: 0;
+
+  flex-grow: 1;
+}
+
+.invalid,
+.invalid * {
+  color: var(--text-color-error) !important;
+
+  text-decoration-line: underline;
+  text-decoration-style: wavy;
+  text-decoration-thickness: 1px;
+  text-decoration-color: var(--text-color-error);
+}
+
+button {
+  user-select: none !important;
+
+  padding: 2px;
+  display: flex;
+  justify-content: center;
+
+  margin: 0;
+
+  & hbox {
+    display: none;
+  }
+}
+
+.sr-remove,
+.close-icon {
+  & hbox {
+    display: initial;
+    padding: 0;
+    margin: 0;
+  }
+
+  opacity: 0.5;
+
+  &:hover {
+    opacity: 0.8;
+  }
+
+  transition: 0.2s opacity cubic-bezier(0.075, 0.82, 0.165, 1);
+
+  appearance: none !important;
+  background: none;
+  border: none !important;
+
+  aspect-ratio: 1;
+  height: 24px;
+  padding: 3px;
+  width: 24px;
+
+  min-width: 0 !important;
+  color: var(--text-color-secondary);
+
+  -moz-context-properties: fill, fill-opacity;
+  fill: currentColor;
+}
+
+#sr-header {
+  width: 100%;
+  padding: var(--content-padding);
+  align-items: center;
+
+  display: flex;
+  flex-direction: row;
+}
+
+.sr-left {
+  margin-left: auto;
+
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  gap: 6px;
+
+  & button {
+    color: var(--text-color);
+    opacity: 1;
+
+    &:hover .sr-remove {
+      opacity: 0.8;
+    }
+  }
+}
+
+#sr-footer {
+  width: 100%;
+  padding: var(--content-padding);
+  align-items: center;
+
+  display: flex;
+  flex-direction: row;
+}
+
+#sr-content {
+  width: 100%;
+  overflow: scroll;
+  padding: var(--content-padding);
+  flex-grow: 1;
+
+  display: flex;
+  flex-direction: column;
+  gap: var(--rules-gap);
+}
+
+.sr-label-container {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+
+  color: var(--text-color-secondary);
+}
+
+.sr-label {
+  margin: 0;
+}
+
+.sr-url-icon,
+.sr-open-in-icon {
+  width: 16px;
+  height: 16px;
+  -moz-context-properties: fill, fill-opacity;
+  fill: currentColor;
+  fill-opacity: 0.65;
+}
--- a/src/zen/space-routing/zen-space-routing.inc.xhtml
+++ b/src/zen/space-routing/zen-space-routing.inc.xhtml
@@ -0,0 +1,108 @@
+#filter substitution
+<?xml version="1.0"?>
+
+# -*- Mode: HTML -*-
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+<!DOCTYPE window>
+
+<window
+  xmlns:html="http://www.w3.org/1999/xhtml"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+  windowtype="Zen:SpaceRouting"
+  customtitlebar="true"
+  id="zenSpaceRoutingDialog"
+  dialogroot="true"
+>
+  <linkset>
+    <html:link rel="stylesheet" href="chrome://global/skin/commonDialog.css" />
+    <html:link
+      rel="stylesheet"
+      href="chrome://global/content/commonDialog.css"
+    />
+    <html:link
+      rel="stylesheet"
+      href="chrome://global/skin/global.css"
+      type="text/css"
+    />
+    <html:link
+      rel="stylesheet"
+      href="chrome://browser/content/zen-styles/zen-theme.css"
+      type="text/css"
+    />
+    <html:link
+      rel="stylesheet"
+      href="chrome://browser/content/zen-styles/zen-space-routing.css"
+      type="text/css"
+    />
+    <html:link
+      rel="stylesheet"
+      href="chrome://browser/skin/zen-icons/icons.css"
+      type="text/css"
+    />
+    <html:link
+      rel="stylesheet"
+      href="chrome://browser/content/zen-styles/zen-animations.css"
+      type="text/css"
+    />
+    <html:link
+      rel="stylesheet"
+      type="text/css"
+      href="chrome://browser/content/zen-styles/zen-popup.css"
+    />
+    <html:link rel="localization" href="browser/zen-space-routing.ftl" />
+  </linkset>
+
+  <vbox
+    id="zen-space-routing-dialog-container"
+    class="dialogBox"
+    role="dialog"
+  >
+    <vbox id="sr-container">
+      <hbox id="sr-header">
+        <h3 data-l10n-id="zen-space-routing-dialog-title"></h3>
+        <html:div class="sr-left">
+          <button
+            id="sr-new-route"
+            data-l10n-id="zen-space-routing-new-route"
+          ></button>
+          <button class="close-icon" data-l10n-id="zen-space-routing-close-button" id="sr-close"></button>
+        </html:div>
+      </hbox>
+      <html:hr class="hr"></html:hr>
+      <vbox id="sr-content">
+        <vbox id="sr-empty-content">
+          <image class="sr-airplane"></image>
+          <p data-l10n-id="zen-space-routing-rulepanel-placeholder"></p>
+        </vbox>
+# All rules will be injected here later
+      </vbox>
+      <html:hr class="hr"></html:hr>
+      <hbox id="sr-footer">
+        <h4 data-l10n-id="zen-space-routing-external-default"></h4>
+        <html:div class="sr-left">
+          <menulist class="select" id="sr-default-external-open-in">
+            <menupopup id="sr-default-external-open-in-popup">
+# Select open in types will be injected here
+            </menupopup>
+          </menulist>
+        </html:div>
+      </hbox>
+    </vbox>
+  </vbox>
+
+  <script>
+    const { nsZenSpaceRoutingDialog } = ChromeUtils.importESModule(
+      "resource:///modules/zen/spacerouting/ZenSpaceRoutingDialog.mjs",
+    );
+    const args = window.arguments?.[0] || {};
+    window.spaceroutingDialog = new nsZenSpaceRoutingDialog(
+      document,
+      window,
+      args.parentWindow,
+    );
+  </script>
+</window>
--- a/src/zen/split-view/ZenViewSplitter.mjs
+++ b/src/zen/split-view/ZenViewSplitter.mjs
@@ -1226,7 +1226,10 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    const currentTab = gZenGlanceManager.getTabOrGlanceParent(
      window.gBrowser.selectedTab
    );
-    const newTab = this.openAndSwitchToTab(url, { inBackground: false });
+    const newTab = this.openAndSwitchToTab(url, {
+      skipRoute: true,
+      inBackground: false,
+    });
    this.splitTabs([currentTab, newTab], undefined, 1);
  }

--- a/src/zen/tests/moz.build
+++ b/src/zen/tests/moz.build
@@ -13,6 +13,7 @@ BROWSER_CHROME_MANIFESTS += [
    "pinned/browser.toml",
    "popover/browser.toml",
    "site_control/browser.toml",
+    "space_routing/browser.toml",
    "spaces/browser.toml",
    "split_view/browser.toml",
    "tabs/browser.toml",
--- a/src/zen/tests/space_routing/browser.toml
+++ b/src/zen/tests/space_routing/browser.toml
@@ -0,0 +1,18 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+[DEFAULT]
+support-files = [
+  "head.js",
+]
+
+["browser_space_routing_crud.js"]
+
+["browser_space_routing_dialog.js"]
+
+["browser_space_routing_on_add_tab.js"]
+
+["browser_space_routing_route_matching.js"]
+
+["browser_space_routing_route_uri.js"]
--- a/src/zen/tests/space_routing/browser_space_routing_crud.js
+++ b/src/zen/tests/space_routing/browser_space_routing_crud.js
@@ -0,0 +1,115 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_setup(async function () {
+  clearAllRoutes();
+  const savedDefault = gZenSpaceRoutingManager.getDefaultExternalRoute();
+  registerCleanupFunction(() => {
+    clearAllRoutes();
+    gZenSpaceRoutingManager.setDefaultExternalRoute(savedDefault);
+  });
+});
+
+add_task(async function test_empty_route_shape_and_unique_ids() {
+  const a = gZenSpaceRoutingManager.getEmptyRoute();
+  const b = gZenSpaceRoutingManager.getEmptyRoute();
+
+  Assert.equal(a.reference, "", "Empty route starts with no reference");
+  Assert.equal(
+    a.openIn,
+    "most-recent-space",
+    "Empty route defaults to most-recent-space"
+  );
+  Assert.equal(a.matchType, "contains", "Empty route defaults to 'contains'");
+  Assert.equal(typeof a.id, "string", "Empty route has a string id");
+  ok(a.id.length, "Empty route id is non-empty");
+  Assert.notEqual(a.id, b.id, "Each empty route gets a unique id");
+});
+
+add_task(async function test_create_get_update_remove_lifecycle() {
+  clearAllRoutes();
+  Assert.equal(
+    gZenSpaceRoutingManager.getAllRoutes().length,
+    0,
+    "Precondition: no routes"
+  );
+
+  const created = gZenSpaceRoutingManager.createNewRoute();
+  Assert.equal(
+    gZenSpaceRoutingManager.getAllRoutes().length,
+    1,
+    "createNewRoute() appends one route"
+  );
+
+  created.reference = "zen-browser.app";
+  created.openIn = "ws-42";
+  created.matchType = "equal-to";
+  gZenSpaceRoutingManager.updateRoute(created);
+
+  const fetched = gZenSpaceRoutingManager.getRoute(created.id);
+  Assert.equal(fetched.reference, "zen-browser.app", "reference persisted");
+  Assert.equal(fetched.openIn, "ws-42", "openIn persisted");
+  Assert.equal(fetched.matchType, "equal-to", "matchType persisted");
+
+  gZenSpaceRoutingManager.removeRoute(created.id);
+  Assert.equal(
+    gZenSpaceRoutingManager.getAllRoutes().length,
+    0,
+    "removeRoute() deletes the route"
+  );
+});
+
+add_task(async function test_remove_only_targets_the_given_id() {
+  clearAllRoutes();
+  const keep1 = addRoute({ reference: "a" });
+  const drop = addRoute({ reference: "b" });
+  const keep2 = addRoute({ reference: "c" });
+
+  gZenSpaceRoutingManager.removeRoute(drop.id);
+
+  const ids = gZenSpaceRoutingManager.getAllRoutes().map(r => r.id);
+  Assert.deepEqual(
+    ids,
+    [keep1.id, keep2.id],
+    "Only the targeted route is removed; order of the rest is preserved"
+  );
+});
+
+add_task(async function test_reads_return_copies_not_internal_refs() {
+  clearAllRoutes();
+  const created = gZenSpaceRoutingManager.createNewRoute();
+
+  const fromGet = gZenSpaceRoutingManager.getRoute(created.id);
+  fromGet.reference = "mutated-via-getRoute";
+  Assert.equal(
+    gZenSpaceRoutingManager.getRoute(created.id).reference,
+    "",
+    "getRoute() returns a copy; external mutation does not leak"
+  );
+
+  const all = gZenSpaceRoutingManager.getAllRoutes();
+  all[0].reference = "mutated-via-getAllRoutes";
+  Assert.equal(
+    gZenSpaceRoutingManager.getRoute(created.id).reference,
+    "",
+    "getAllRoutes() returns copies; external mutation does not leak"
+  );
+});
+
+add_task(async function test_default_external_route_getter_setter() {
+  gZenSpaceRoutingManager.setDefaultExternalRoute("ws-default");
+  Assert.equal(
+    gZenSpaceRoutingManager.getDefaultExternalRoute(),
+    "ws-default",
+    "setDefaultExternalRoute() round-trips through the getter"
+  );
+
+  gZenSpaceRoutingManager.setDefaultExternalRoute("most-recent-space");
+  Assert.equal(
+    gZenSpaceRoutingManager.getDefaultExternalRoute(),
+    "most-recent-space",
+    "The default external route can be changed again"
+  );
+});
--- a/src/zen/tests/space_routing/browser_space_routing_dialog.js
+++ b/src/zen/tests/space_routing/browser_space_routing_dialog.js
@@ -0,0 +1,251 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_setup(async function () {
+  clearAllRoutes();
+  const savedDefault = gZenSpaceRoutingManager.getDefaultExternalRoute();
+  registerCleanupFunction(() => {
+    clearAllRoutes();
+    gZenSpaceRoutingManager.setDefaultExternalRoute(savedDefault);
+  });
+});
+
+add_task(async function test_empty_placeholder_and_add_route() {
+  clearAllRoutes();
+  const dlg = await openRoutingDialog();
+  try {
+    const doc = dlg.document;
+    const emptyText = doc.getElementById("sr-empty-content");
+    const content = doc.getElementById("sr-content");
+
+    Assert.notEqual(
+      emptyText.style.display,
+      "none",
+      "The empty-state placeholder is visible when there are no routes"
+    );
+
+    doc.getElementById("sr-new-route").click();
+
+    Assert.equal(
+      content.querySelectorAll(".sr-rule-container").length,
+      1,
+      "Clicking 'New Route' injects one route element"
+    );
+    Assert.equal(
+      emptyText.style.display,
+      "none",
+      "The empty-state placeholder is hidden once a route exists"
+    );
+    Assert.equal(
+      gZenSpaceRoutingManager.getAllRoutes().length,
+      1,
+      "The new route is persisted into the manager"
+    );
+  } finally {
+    await closeRoutingDialog(dlg);
+    clearAllRoutes();
+  }
+});
+
+add_task(async function test_remove_route_via_ui() {
+  clearAllRoutes();
+  addRoute({ reference: "github.com" });
+  const dlg = await openRoutingDialog();
+  try {
+    const doc = dlg.document;
+    Assert.equal(
+      doc.querySelectorAll(".sr-rule-container").length,
+      1,
+      "Existing route is rendered on open"
+    );
+
+    doc.querySelector(".sr-remove").click();
+
+    Assert.equal(
+      doc.querySelectorAll(".sr-rule-container").length,
+      0,
+      "The route element is removed from the DOM"
+    );
+    Assert.equal(
+      gZenSpaceRoutingManager.getAllRoutes().length,
+      0,
+      "The route is removed from the manager"
+    );
+    Assert.equal(
+      doc.getElementById("sr-empty-content").style.display,
+      "flex",
+      "The empty-state placeholder returns after the last route is removed"
+    );
+  } finally {
+    await closeRoutingDialog(dlg);
+    clearAllRoutes();
+  }
+});
+
+add_task(async function test_match_type_updates_placeholder_and_store() {
+  clearAllRoutes();
+  const route = addRoute({ reference: "", matchType: "contains" });
+  const dlg = await openRoutingDialog();
+  try {
+    const doc = dlg.document;
+    const menulist = doc.querySelector(".sr-rule-container .match-type-select");
+    const input = doc.querySelector(".sr-rule-container .input");
+
+    Assert.equal(
+      input.placeholder,
+      "zen-browser.app",
+      "The 'contains' placeholder is the plain domain"
+    );
+
+    menulist.value = "regex";
+    menulist.dispatchEvent(new Event("command", { bubbles: true }));
+
+    Assert.equal(
+      input.placeholder,
+      "zen-browser\\.app",
+      "Switching to 'regex' updates the placeholder to an escaped pattern"
+    );
+    Assert.equal(
+      gZenSpaceRoutingManager.getRoute(route.id).matchType,
+      "regex",
+      "The match type change is persisted to the manager"
+    );
+  } finally {
+    await closeRoutingDialog(dlg);
+    clearAllRoutes();
+  }
+});
+
+add_task(async function test_invalid_regex_is_flagged_and_not_saved() {
+  clearAllRoutes();
+  const route = addRoute({ reference: "", matchType: "regex" });
+  const dlg = await openRoutingDialog();
+  try {
+    const doc = dlg.document;
+    const input = doc.querySelector(".sr-rule-container .input");
+
+    input.value = "([";
+    input.dispatchEvent(new Event("input", { bubbles: true }));
+
+    ok(
+      input.classList.contains("invalid"),
+      "An invalid regex marks the input as invalid"
+    );
+    Assert.equal(
+      gZenSpaceRoutingManager.getRoute(route.id).reference,
+      "",
+      "An invalid regex is NOT written to the route"
+    );
+
+    input.value = "zen.*app";
+    input.dispatchEvent(new Event("input", { bubbles: true }));
+
+    ok(
+      !input.classList.contains("invalid"),
+      "A subsequently valid regex clears the invalid state"
+    );
+    Assert.equal(
+      gZenSpaceRoutingManager.getRoute(route.id).reference,
+      "zen.*app",
+      "A valid regex is written to the route"
+    );
+  } finally {
+    await closeRoutingDialog(dlg);
+    clearAllRoutes();
+  }
+});
+
+add_task(async function test_default_external_select_updates_store() {
+  clearAllRoutes();
+  await gZenWorkspaces.promiseInitialized;
+  gZenSpaceRoutingManager.setDefaultExternalRoute("most-recent-space");
+
+  const dlg = await openRoutingDialog();
+  try {
+    const doc = dlg.document;
+    const select = doc.getElementById("sr-default-external-open-in");
+
+    await TestUtils.waitForCondition(
+      () => select.querySelectorAll("menuitem").length > 1,
+      "External-default options were populated"
+    );
+
+    const workspaceUuid = gZenWorkspaces.getWorkspaces()[0].uuid;
+    select.value = workspaceUuid;
+    select.dispatchEvent(new Event("command", { bubbles: true }));
+
+    Assert.equal(
+      gZenSpaceRoutingManager.getDefaultExternalRoute(),
+      workspaceUuid,
+      "Changing the external-default select updates the manager"
+    );
+  } finally {
+    await closeRoutingDialog(dlg);
+    gZenSpaceRoutingManager.setDefaultExternalRoute("most-recent-space");
+  }
+});
+
+add_task(async function test_routes_are_saved_on_close() {
+  clearAllRoutes();
+  const dlg = await openRoutingDialog();
+
+  let saveCalls = 0;
+  const realSave = gZenSpaceRoutingManager.saveRoutes;
+  gZenSpaceRoutingManager.saveRoutes = function () {
+    saveCalls++;
+    return realSave.call(this);
+  };
+
+  try {
+    const closed = BrowserTestUtils.domWindowClosed(dlg);
+    dlg.close();
+    await TestUtils.waitForCondition(
+      () => saveCalls > 0,
+      "Closing the dialog flushes routes to disk via saveRoutes()"
+    );
+    await closed;
+  } finally {
+    delete gZenSpaceRoutingManager.saveRoutes;
+  }
+});
+
+add_task(async function test_open_broadcasts_kill_to_other_instances() {
+  clearAllRoutes();
+
+  let killNotified = false;
+  const observer = {
+    observe(_subject, topic) {
+      if (topic === "zen-space-routing-kill") {
+        killNotified = true;
+      }
+    },
+  };
+  Services.obs.addObserver(observer, "zen-space-routing-kill");
+
+  let dlg;
+  try {
+    dlg = await openRoutingDialog();
+    ok(
+      killNotified,
+      "Opening a dialog broadcasts 'zen-space-routing-kill' so others can close"
+    );
+  } finally {
+    Services.obs.removeObserver(observer, "zen-space-routing-kill");
+    if (dlg) {
+      await closeRoutingDialog(dlg);
+    }
+  }
+});
+
+add_task(async function test_kill_notification_closes_dialog() {
+  clearAllRoutes();
+  const dlg = await openRoutingDialog();
+
+  const closed = BrowserTestUtils.domWindowClosed(dlg);
+  Services.obs.notifyObservers(null, "zen-space-routing-kill");
+  await closed;
+
+  ok(dlg.closed, "A 'zen-space-routing-kill' notification closes the dialog");
+});
--- a/src/zen/tests/space_routing/browser_space_routing_on_add_tab.js
+++ b/src/zen/tests/space_routing/browser_space_routing_on_add_tab.js
@@ -0,0 +1,363 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TARGET_WS = { uuid: "ws-target", containerTabId: 7 };
+
+add_setup(async function () {
+  clearAllRoutes();
+  registerCleanupFunction(() => clearAllRoutes());
+});
+
+add_task(async function test_onBeforeAddTab_resolves_container_for_match() {
+  clearAllRoutes();
+  addRoute({
+    reference: "github.com",
+    matchType: "contains",
+    openIn: TARGET_WS.uuid,
+  });
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  const result = gZenSpaceRoutingManager.onBeforeAddTab(
+    "https://github.com/zen",
+    {},
+    win
+  );
+
+  Assert.deepEqual(
+    result,
+    {
+      shouldEarlyExit: false,
+      userContextId: TARGET_WS.containerTabId,
+      isRouteFound: true,
+      targetRoute: TARGET_WS.uuid,
+    },
+    "A matching route resolves to the workspace's containerTabId"
+  );
+});
+
+add_task(async function test_onBeforeAddTab_no_match_returns_no_route() {
+  clearAllRoutes();
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  const result = gZenSpaceRoutingManager.onBeforeAddTab(
+    "https://example.com",
+    {},
+    win
+  );
+
+  Assert.deepEqual(
+    result,
+    {
+      shouldEarlyExit: false,
+      userContextId: null,
+      isRouteFound: false,
+      targetRoute: "most-recent-space",
+    },
+    "An unmatched URL (most-recent-space) reports no container and no route"
+  );
+});
+
+add_task(async function test_onBeforeAddTab_route_to_missing_workspace() {
+  clearAllRoutes();
+  addRoute({
+    reference: "github.com",
+    matchType: "contains",
+    openIn: "ws-does-not-exist",
+  });
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  const result = gZenSpaceRoutingManager.onBeforeAddTab(
+    "https://github.com",
+    {},
+    win
+  );
+
+  Assert.deepEqual(
+    result,
+    {
+      shouldEarlyExit: false,
+      userContextId: null,
+      isRouteFound: false,
+      targetRoute: "ws-does-not-exist",
+    },
+    "A route to a non-existent workspace yields no container and no route"
+  );
+});
+
+add_task(async function test_onBeforeAddTab_skips_special_tab_options() {
+  clearAllRoutes();
+  addRoute({
+    reference: "github.com",
+    matchType: "contains",
+    openIn: TARGET_WS.uuid,
+  });
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  for (const skipOption of ["skipRoute", "pinned", "tabGroup"]) {
+    const result = gZenSpaceRoutingManager.onBeforeAddTab(
+      "https://github.com/zen",
+      { [skipOption]: true },
+      win
+    );
+    Assert.deepEqual(
+      result,
+      {
+        shouldEarlyExit: false,
+        userContextId: null,
+        isRouteFound: false,
+        targetRoute: null,
+      },
+      `Option '${skipOption}' skips routing even though a rule matches`
+    );
+  }
+});
+
+add_task(async function test_onBeforeAddTab_skips_until_startup_ready() {
+  clearAllRoutes();
+  addRoute({
+    reference: "github.com",
+    matchType: "contains",
+    openIn: TARGET_WS.uuid,
+  });
+  const win = makeFakeWindow({ ready: false, workspaces: [TARGET_WS] });
+
+  const result = gZenSpaceRoutingManager.onBeforeAddTab(
+    "https://github.com/zen",
+    {},
+    win
+  );
+
+  Assert.deepEqual(
+    result,
+    {
+      shouldEarlyExit: false,
+      userContextId: null,
+      isRouteFound: false,
+      targetRoute: null,
+    },
+    "While gZenStartup.isReady is false (session restore), routing is skipped"
+  );
+});
+
+add_task(async function test_onAfterAddTab_moves_tab_on_non_origin_window() {
+  clearAllRoutes();
+  addRoute({
+    reference: "github.com",
+    matchType: "contains",
+    openIn: TARGET_WS.uuid,
+  });
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+  const fakeTab = { parentNode: {} };
+
+  gZenSpaceRoutingManager.onAfterAddTab(
+    "https://github.com/zen",
+    fakeTab,
+    {},
+    win,
+    { targetRoute: TARGET_WS.uuid }
+  );
+
+  await TestUtils.waitForCondition(
+    () => win.gZenWorkspaces.moveCalls.length === 1,
+    "moveTabToWorkspace was called once"
+  );
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls[0].uuid,
+    TARGET_WS.uuid,
+    "The tab is moved to the matched workspace"
+  );
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls[0].tab,
+    fakeTab,
+    "The correct tab element is moved"
+  );
+  Assert.equal(
+    win.gZenWorkspaces.changeCalls.length,
+    0,
+    "A non-originating window does not switch the active workspace"
+  );
+});
+
+add_task(async function test_onAfterAddTab_reuses_before_result() {
+  clearAllRoutes();
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+  const fakeTab = { parentNode: {} };
+
+  // No routes exist, so a fresh routeUri() would yield "most-recent-space" and
+  // move nothing. The tab is still moved to TARGET_WS, proving onAfterAddTab
+  // routes purely from the precomputed result rather than recomputing.
+  gZenSpaceRoutingManager.onAfterAddTab(
+    "https://example.com",
+    fakeTab,
+    {},
+    win,
+    { targetRoute: TARGET_WS.uuid }
+  );
+
+  await TestUtils.waitForCondition(
+    () => win.gZenWorkspaces.moveCalls.length === 1,
+    "moveTabToWorkspace used the precomputed route"
+  );
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls[0].uuid,
+    TARGET_WS.uuid,
+    "onAfterAddTab routes using the precomputed targetRoute, not a fresh routeUri()"
+  );
+});
+
+add_task(async function test_onAfterAddTab_ignores_detached_tab() {
+  clearAllRoutes();
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  gZenSpaceRoutingManager.onAfterAddTab(
+    "https://github.com/zen",
+    { parentNode: null },
+    {},
+    win,
+    { targetRoute: TARGET_WS.uuid }
+  );
+  await flushEventLoop();
+
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls.length,
+    0,
+    "A detached tab (no parentNode) is never moved"
+  );
+});
+
+add_task(
+  async function test_onAfterAddTab_does_nothing_for_most_recent_space() {
+    clearAllRoutes();
+    const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+    gZenSpaceRoutingManager.onAfterAddTab(
+      "https://example.com",
+      { parentNode: {} },
+      {},
+      win,
+      { targetRoute: "most-recent-space" }
+    );
+    await flushEventLoop();
+
+    Assert.equal(
+      win.gZenWorkspaces.moveCalls.length,
+      0,
+      "A 'most-recent-space' route does not move the tab"
+    );
+  }
+);
+
+add_task(async function test_onAfterAddTab_does_nothing_when_skipped() {
+  clearAllRoutes();
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  // onBeforeAddTab reports targetRoute null for skipped/unready tabs; without a
+  // route there is nothing for onAfterAddTab to do.
+  gZenSpaceRoutingManager.onAfterAddTab(
+    "https://github.com/zen",
+    { parentNode: {} },
+    {},
+    win,
+    { targetRoute: null }
+  );
+  await flushEventLoop();
+
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls.length,
+    0,
+    "A null targetRoute (skipped tab) is not routed"
+  );
+});
+
+add_task(async function test_onAfterAddTab_ignores_missing_before_result() {
+  clearAllRoutes();
+  const win = makeFakeWindow({ ready: true, workspaces: [TARGET_WS] });
+
+  gZenSpaceRoutingManager.onAfterAddTab(
+    "https://github.com/zen",
+    { parentNode: {} },
+    {},
+    win
+  );
+  await flushEventLoop();
+
+  Assert.equal(
+    win.gZenWorkspaces.moveCalls.length,
+    0,
+    "Without a beforeResult there is no precomputed route, so nothing is moved"
+  );
+});
+
+add_task(async function test_onAfterAddTab_activates_workspace_on_origin() {
+  clearAllRoutes();
+  await gZenWorkspaces.promiseInitialized;
+
+  await gZenWorkspaces.createAndSaveWorkspace("SR Origin Test");
+  const workspaces = gZenWorkspaces.getWorkspaces();
+  const target = workspaces[workspaces.length - 1];
+
+  const isOriginating =
+    window === Services.wm.getMostRecentWindow("navigator:browser");
+  ok(isOriginating, "Precondition: the test window is the most-recent window");
+
+  const ws = window.gZenWorkspaces;
+  const origMove = ws.moveTabToWorkspace;
+  const origChange = ws.changeWorkspace;
+  const origLastSelected = ws.lastSelectedWorkspaceTabs;
+
+  let moved = null;
+  let changedTo = null;
+  ws.lastSelectedWorkspaceTabs = {};
+  ws.moveTabToWorkspace = (tab, uuid) => {
+    moved = { tab, uuid };
+  };
+  ws.changeWorkspace = workspace => {
+    changedTo = workspace;
+    return Promise.resolve();
+  };
+
+  const tab = BrowserTestUtils.addTab(gBrowser, "about:blank", {
+    skipAnimation: true,
+    skipRoute: true,
+  });
+
+  try {
+    gZenSpaceRoutingManager.onAfterAddTab(
+      "https://github.com/zen",
+      tab,
+      {},
+      window,
+      { targetRoute: target.uuid }
+    );
+
+    await TestUtils.waitForCondition(
+      () => moved,
+      "moveTabToWorkspace was called"
+    );
+    Assert.equal(moved.uuid, target.uuid, "Moved to the matched workspace");
+    Assert.equal(moved.tab, tab, "Moved the tab we passed in");
+
+    await TestUtils.waitForCondition(
+      () => changedTo,
+      "changeWorkspace was called on the originating window"
+    );
+    Assert.equal(
+      changedTo.uuid,
+      target.uuid,
+      "Activated the matched workspace"
+    );
+    Assert.equal(
+      ws.lastSelectedWorkspaceTabs[target.uuid],
+      tab,
+      "The moved tab is remembered as the workspace's last-selected tab"
+    );
+  } finally {
+    ws.moveTabToWorkspace = origMove;
+    ws.changeWorkspace = origChange;
+    ws.lastSelectedWorkspaceTabs = origLastSelected;
+    BrowserTestUtils.removeTab(tab);
+    await gZenWorkspaces.removeWorkspace(target.uuid);
+  }
+});
--- a/src/zen/tests/space_routing/browser_space_routing_route_matching.js
+++ b/src/zen/tests/space_routing/browser_space_routing_route_matching.js
@@ -0,0 +1,108 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_contains_is_case_insensitive_substring() {
+  const route = { reference: "GitHub", matchType: "contains" };
+
+  ok(
+    gZenSpaceRoutingManager.isRouteMatching("https://github.com/zen", route),
+    "'contains' matches a substring regardless of case"
+  );
+  ok(
+    gZenSpaceRoutingManager.isRouteMatching("https://api.GITHUB.com/v3", route),
+    "'contains' matches when the URL casing differs from the reference"
+  );
+  ok(
+    !gZenSpaceRoutingManager.isRouteMatching("https://gitlab.com/zen", route),
+    "'contains' rejects a URL that does not include the reference"
+  );
+});
+
+add_task(async function test_equal_to_normalizes_protocol_and_www() {
+  const route = { reference: "github.com", matchType: "equal-to" };
+
+  ok(
+    gZenSpaceRoutingManager.isRouteMatching("https://www.github.com/", route),
+    "'equal-to' ignores https://, www. and a trailing slash"
+  );
+  ok(
+    gZenSpaceRoutingManager.isRouteMatching("HTTP://GitHub.com", route),
+    "'equal-to' is case-insensitive and strips http://"
+  );
+  ok(
+    !gZenSpaceRoutingManager.isRouteMatching("https://github.com/zen", route),
+    "'equal-to' does not match when a path is present (not an exact host)"
+  );
+  ok(
+    !gZenSpaceRoutingManager.isRouteMatching("https://notgithub.com", route),
+    "'equal-to' requires the whole normalized URL to be equal"
+  );
+});
+
+add_task(async function test_regex_match_is_case_sensitive_on_raw_uri() {
+  ok(
+    gZenSpaceRoutingManager.isRouteMatching("https://zen-browser.app", {
+      reference: "^https://.*\\.app$",
+      matchType: "regex",
+    }),
+    "'regex' matches against the raw URI"
+  );
+
+  ok(
+    !gZenSpaceRoutingManager.isRouteMatching("https://github.com", {
+      reference: "GitHub",
+      matchType: "regex",
+    }),
+    "'regex' is case-sensitive (no implicit lower-casing like 'contains')"
+  );
+});
+
+add_task(async function test_invalid_regex_is_swallowed() {
+  let threw = false;
+  let result;
+  try {
+    result = gZenSpaceRoutingManager.isRouteMatching(
+      "https://zen-browser.app",
+      {
+        reference: "([",
+        matchType: "regex",
+      }
+    );
+  } catch (e) {
+    threw = true;
+  }
+
+  ok(!threw, "An invalid regex does not throw out of isRouteMatching");
+  Assert.strictEqual(result, false, "An invalid regex never matches");
+});
+
+add_task(async function test_empty_reference_never_matches() {
+  for (const matchType of ["contains", "equal-to", "regex"]) {
+    ok(
+      !gZenSpaceRoutingManager.isRouteMatching("https://github.com", {
+        reference: "",
+        matchType,
+      }),
+      `An empty reference never matches (${matchType})`
+    );
+    ok(
+      !gZenSpaceRoutingManager.isRouteMatching("https://github.com", {
+        reference: "   ",
+        matchType,
+      }),
+      `A whitespace-only reference never matches (${matchType})`
+    );
+  }
+});
+
+add_task(async function test_unknown_match_type_does_not_match() {
+  ok(
+    !gZenSpaceRoutingManager.isRouteMatching("https://github.com", {
+      reference: "github.com",
+      matchType: "starts-with",
+    }),
+    "An unsupported match type falls through to no match"
+  );
+});
--- a/src/zen/tests/space_routing/browser_space_routing_route_uri.js
+++ b/src/zen/tests/space_routing/browser_space_routing_route_uri.js
@@ -0,0 +1,66 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_setup(async function () {
+  clearAllRoutes();
+  const savedDefault = gZenSpaceRoutingManager.getDefaultExternalRoute();
+  registerCleanupFunction(() => {
+    clearAllRoutes();
+    gZenSpaceRoutingManager.setDefaultExternalRoute(savedDefault);
+  });
+});
+
+add_task(async function test_no_match_returns_most_recent_space() {
+  clearAllRoutes();
+  addRoute({ reference: "github.com", matchType: "contains", openIn: "ws-1" });
+
+  Assert.equal(
+    gZenSpaceRoutingManager.routeUri("https://example.com", {}),
+    "most-recent-space",
+    "A non-matching, non-external URL routes to most-recent-space"
+  );
+});
+
+add_task(async function test_first_matching_route_wins() {
+  clearAllRoutes();
+  addRoute({ reference: "github", matchType: "contains", openIn: "ws-first" });
+  addRoute({ reference: "github", matchType: "contains", openIn: "ws-second" });
+
+  Assert.equal(
+    gZenSpaceRoutingManager.routeUri("https://github.com/zen", {}),
+    "ws-first",
+    "The openIn of the first matching route is returned, later matches ignored"
+  );
+});
+
+add_task(async function test_external_default_only_applies_without_match() {
+  clearAllRoutes();
+  gZenSpaceRoutingManager.setDefaultExternalRoute("ws-external");
+  addRoute({ reference: "github", matchType: "contains", openIn: "ws-rule" });
+
+  Assert.equal(
+    gZenSpaceRoutingManager.routeUri("https://github.com", {
+      fromExternal: true,
+    }),
+    "ws-rule",
+    "A matching rule wins even for external links"
+  );
+
+  Assert.equal(
+    gZenSpaceRoutingManager.routeUri("https://example.com", {
+      fromExternal: true,
+    }),
+    "ws-external",
+    "An unmatched external link uses the default external route"
+  );
+
+  Assert.equal(
+    gZenSpaceRoutingManager.routeUri("https://example.com", {
+      fromExternal: false,
+    }),
+    "most-recent-space",
+    "An unmatched internal link ignores the external default"
+  );
+});
--- a/src/zen/tests/space_routing/head.js
+++ b/src/zen/tests/space_routing/head.js
@@ -0,0 +1,80 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { gZenSpaceRoutingManager } = ChromeUtils.importESModule(
+  "resource:///modules/zen/spacerouting/ZenSpaceRoutingManager.sys.mjs"
+);
+
+const SR_DIALOG_URI =
+  "chrome://browser/content/zen-components/windows/zen-space-routing.xhtml";
+
+function clearAllRoutes() {
+  for (const route of gZenSpaceRoutingManager.getAllRoutes()) {
+    gZenSpaceRoutingManager.removeRoute(route.id);
+  }
+}
+
+function addRoute({
+  reference = "",
+  openIn = "most-recent-space",
+  matchType = "contains",
+} = {}) {
+  const route = gZenSpaceRoutingManager.createNewRoute();
+  route.reference = reference;
+  route.openIn = openIn;
+  route.matchType = matchType;
+  gZenSpaceRoutingManager.updateRoute(route);
+  return route;
+}
+
+function makeFakeWindow({ ready = true, workspaces = [] } = {}) {
+  return {
+    gZenStartup: { isReady: ready },
+    gZenWorkspaces: {
+      moveCalls: [],
+      changeCalls: [],
+      lastSelectedWorkspaceTabs: {},
+      getWorkspaceFromId(id) {
+        return workspaces.find(w => w.uuid === id) || null;
+      },
+      moveTabToWorkspace(tab, uuid) {
+        this.moveCalls.push({ tab, uuid });
+      },
+      changeWorkspace(workspace) {
+        this.changeCalls.push(workspace);
+        return Promise.resolve();
+      },
+    },
+  };
+}
+
+async function flushEventLoop() {
+  for (let i = 0; i < 5; i++) {
+    await new Promise(resolve => Services.tm.dispatchToMainThread(resolve));
+  }
+}
+
+async function openRoutingDialog() {
+  const dialogPromise = BrowserTestUtils.domWindowOpenedAndLoaded(null, win =>
+    win.document?.documentURI?.includes("zen-space-routing.xhtml")
+  );
+  executeSoon(() => gZenSpaceRoutingManager.openSpaceRoutingDialog(window));
+  const dialogWin = await dialogPromise;
+  await SimpleTest.promiseFocus(dialogWin);
+  await TestUtils.waitForCondition(
+    () => dialogWin.spaceroutingDialog?.initialized,
+    "Space Routing dialog finished initializing"
+  );
+  return dialogWin;
+}
+
+async function closeRoutingDialog(dialogWin) {
+  if (dialogWin.closed) {
+    return;
+  }
+  const closed = BrowserTestUtils.domWindowClosed(dialogWin);
+  dialogWin.close();
+  await closed;
+}
--- a/src/zen/urlbar/ZenUBGlobalActions.sys.mjs
+++ b/src/zen/urlbar/ZenUBGlobalActions.sys.mjs
@@ -81,6 +81,11 @@ const globalActionsTemplate = [
      return !tab.hasAttribute("zen-empty-tab") && tab.pinned;
    },
  },
+  {
+    label: "Open Space Routing",
+    command: "cmd_zenOpenSpaceRoutingSettings",
+    icon: "chrome://browser/skin/zen-icons/selectable/airplane.svg",
+  },
  {
    label: "New Boost",
    icon: "chrome://browser/skin/zen-icons/boost.svg",
--- a/src/zen/zen.globals.mjs
+++ b/src/zen/zen.globals.mjs
@@ -40,6 +40,8 @@ export default [

  "gZenViewSplitter",

+  "gZenSpaceRoutingManager",
+
  "Ci",
  "Cu",
  "Cc",