diff --git a/app/metrics.yaml b/app/metrics.yaml
index 5b57fe956e..003f505232 100644
--- a/app/metrics.yaml
+++ b/app/metrics.yaml
@@ -2625,7 +2625,11 @@ tabs_tray:
   opened_existing_tab:
     type: event
     description: |
-      A user opened an existing tab
+      A user opened an existing tab from a particular app feature.
+    extra_keys:
+      source:
+        description: |
+          From which app feature was an existing tab opened.
     bugs:
       - https://github.com/mozilla-mobile/fenix/issues/11273
     data_reviews:
@@ -2633,15 +2637,20 @@ tabs_tray:
       - https://github.com/mozilla-mobile/fenix/pull/15713#issuecomment-703972068
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
       - https://github.com/mozilla-mobile/fenix/pull/20517#pullrequestreview-718069041
+      - https://github.com/mozilla-mobile/fenix/pull/20508#issuecomment-902160532
     data_sensitivity:
       - interaction
     notification_emails:
       - android-probes@mozilla.com
-    expires: "2022-02-01"
+    expires: "2022-08-01"
   closed_existing_tab:
     type: event
     description: |
-      A user closed an existing tab
+      A user closed an existing tab from a particular app feature.
+    extra_keys:
+      source:
+        description: |
+          From which app feature was an existing tab closed.
     bugs:
       - https://github.com/mozilla-mobile/fenix/issues/11273
     data_reviews:
@@ -2649,11 +2658,12 @@ tabs_tray:
       - https://github.com/mozilla-mobile/fenix/pull/15713#issuecomment-703972068
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
       - https://github.com/mozilla-mobile/fenix/pull/20517#pullrequestreview-718069041
+      - https://github.com/mozilla-mobile/fenix/pull/20508#issuecomment-902160532
     data_sensitivity:
       - interaction
     notification_emails:
       - android-probes@mozilla.com
-    expires: "2022-02-01"
+    expires: "2022-08-01"
   private_mode_tapped:
     type: event
     description: |
@@ -2811,6 +2821,34 @@ tabs_tray:
     notification_emails:
       - android-probes@mozilla.com
     expires: "2022-08-01"
+  inactive_tabs_expanded:
+    type: event
+    description: |
+      A user tapped the "Inactive tabs" header to expand
+      the group of inactive tabs.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/20507
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/20508#issuecomment-901336677
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - android-probes@mozilla.com
+    expires: "2022-08-01"
+  inactive_tabs_collapsed:
+    type: event
+    description: |
+      A user tapped the "Inactive tabs" header to collapse
+      the group of inactive tabs.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/20507
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/20508#issuecomment-901336677
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - android-probes@mozilla.com
+    expires: "2022-08-01"
 
 collections:
   renamed:
diff --git a/app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt b/app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt
index 0e627b7e46..bb50f927b5 100644
--- a/app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt
+++ b/app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt
@@ -21,6 +21,7 @@ import org.mozilla.fenix.GleanMetrics.Logins
 import org.mozilla.fenix.GleanMetrics.Onboarding
 import org.mozilla.fenix.GleanMetrics.ProgressiveWebApp
 import org.mozilla.fenix.GleanMetrics.SearchShortcuts
+import org.mozilla.fenix.GleanMetrics.TabsTray
 import org.mozilla.fenix.GleanMetrics.Tip
 import org.mozilla.fenix.GleanMetrics.ToolbarSettings
 import org.mozilla.fenix.GleanMetrics.TopSites
@@ -175,8 +176,12 @@ sealed class Event {
     // Tab tray
     object TabsTrayOpened : Event()
     object TabsTrayClosed : Event()
-    object OpenedExistingTab : Event()
-    object ClosedExistingTab : Event()
+    data class OpenedExistingTab(val source: String) : Event() {
+        override val extras = mapOf(TabsTray.openedExistingTabKeys.source to source)
+    }
+    data class ClosedExistingTab(val source: String) : Event() {
+        override val extras = mapOf(TabsTray.closedExistingTabKeys.source to source)
+    }
     object TabsTrayPrivateModeTapped : Event()
     object TabsTrayNormalModeTapped : Event()
     object TabsTraySyncedModeTapped : Event()
@@ -187,6 +192,8 @@ sealed class Event {
     object TabsTrayShareAllTabsPressed : Event()
     object TabsTrayCloseAllTabsPressed : Event()
     object TabsTrayRecentlyClosedPressed : Event()
+    object TabsTrayInactiveTabsExpanded : Event()
+    object TabsTrayInactiveTabsCollapsed : Event()
 
     object ProgressiveWebAppOpenFromHomescreenTap : Event()
     object ProgressiveWebAppInstallAsShortcut : Event()
diff --git a/app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt b/app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt
index 1e3fc18b57..7472e4f0ec 100644
--- a/app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt
+++ b/app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt
@@ -650,11 +650,13 @@ private val Event.wrapper: EventWrapper<*>?
         is Event.TabsTrayClosed -> EventWrapper<NoExtraKeys>(
             { TabsTray.closed.record(it) }
         )
-        is Event.OpenedExistingTab -> EventWrapper<NoExtraKeys>(
-            { TabsTray.openedExistingTab.record(it) }
+        is Event.OpenedExistingTab -> EventWrapper(
+            { TabsTray.openedExistingTab.record(it) },
+            { TabsTray.openedExistingTabKeys.valueOf(it) }
         )
-        is Event.ClosedExistingTab -> EventWrapper<NoExtraKeys>(
-            { TabsTray.closedExistingTab.record(it) }
+        is Event.ClosedExistingTab -> EventWrapper(
+            { TabsTray.closedExistingTab.record(it) },
+            { TabsTray.closedExistingTabKeys.valueOf(it) }
         )
         is Event.TabsTrayPrivateModeTapped -> EventWrapper<NoExtraKeys>(
             { TabsTray.privateModeTapped.record(it) }
@@ -686,6 +688,12 @@ private val Event.wrapper: EventWrapper<*>?
         is Event.TabsTrayRecentlyClosedPressed -> EventWrapper<NoExtraKeys>(
             { TabsTray.inactiveTabsRecentlyClosed.record(it) }
         )
+        is Event.TabsTrayInactiveTabsExpanded -> EventWrapper<NoExtraKeys>(
+            { TabsTray.inactiveTabsExpanded.record(it) }
+        )
+        is Event.TabsTrayInactiveTabsCollapsed -> EventWrapper<NoExtraKeys>(
+            { TabsTray.inactiveTabsCollapsed.record(it) }
+        )
         is Event.AutoPlaySettingVisited -> EventWrapper<NoExtraKeys>(
             { Autoplay.visitedSetting.record(it) }
         )
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/TrayPagerAdapter.kt b/app/src/main/java/org/mozilla/fenix/tabstray/TrayPagerAdapter.kt
index cbeeb757b2..da04b28098 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/TrayPagerAdapter.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/TrayPagerAdapter.kt
@@ -35,11 +35,11 @@ class TrayPagerAdapter(
 
     private val normalAdapter by lazy {
         ConcatAdapter(
-            BrowserTabsAdapter(context, browserInteractor, store),
-            InactiveTabsAdapter(context, browserInteractor)
+            BrowserTabsAdapter(context, browserInteractor, store, TABS_TRAY_FEATURE_NAME),
+            InactiveTabsAdapter(context, browserInteractor, INACTIVE_TABS_FEATURE_NAME)
         )
     }
-    private val privateAdapter by lazy { BrowserTabsAdapter(context, browserInteractor, store) }
+    private val privateAdapter by lazy { BrowserTabsAdapter(context, browserInteractor, store, TABS_TRAY_FEATURE_NAME) }
     private val syncedTabsAdapter by lazy { SyncedTabsAdapter(TabClickDelegate(navInteractor)) }
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): AbstractPageViewHolder {
@@ -98,6 +98,10 @@ class TrayPagerAdapter(
     companion object {
         const val TRAY_TABS_COUNT = 3
 
+        // Telemetry keys for identifying from which app features the a was opened / closed.
+        const val TABS_TRAY_FEATURE_NAME = "Tabs tray"
+        const val INACTIVE_TABS_FEATURE_NAME = "Inactive tabs"
+
         val POSITION_NORMAL_TABS = Page.NormalTabs.ordinal
         val POSITION_PRIVATE_TABS = Page.PrivateTabs.ordinal
         val POSITION_SYNCED_TABS = Page.SyncedTabs.ordinal
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolder.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolder.kt
index 02b81a09b9..34c5c1dbd6 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolder.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolder.kt
@@ -35,19 +35,28 @@ import org.mozilla.fenix.ext.removeTouchDelegate
 import org.mozilla.fenix.ext.showAndEnable
 import org.mozilla.fenix.ext.toShortUrl
 import org.mozilla.fenix.selection.SelectionHolder
-import org.mozilla.fenix.selection.SelectionInteractor
 import org.mozilla.fenix.tabstray.TabsTrayState
 import org.mozilla.fenix.tabstray.TabsTrayStore
 import org.mozilla.fenix.tabstray.ext.isSelect
 
 /**
  * A RecyclerView ViewHolder implementation for "tab" items.
+ *
+ * @param itemView [View] that displays a "tab".
+ * @param imageLoader [ImageLoader] used to load tab thumbnails.
+ * @param trayStore [TabsTrayStore] containing the complete state of tabs tray and methods to update that.
+ * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
+ * @param store [BrowserStore] containing the complete state of the browser and methods to update that.
+ * @param metrics [MetricController] used for handling telemetry events.
  */
+@Suppress("LongParameterList")
 abstract class AbstractBrowserTabViewHolder(
     itemView: View,
     private val imageLoader: ImageLoader,
     private val trayStore: TabsTrayStore,
     private val selectionHolder: SelectionHolder<Tab>?,
+    @VisibleForTesting
+    internal val featureName: String,
     private val store: BrowserStore = itemView.context.components.core.store,
     private val metrics: MetricController = itemView.context.components.analytics.metrics
 ) : TabViewHolder(itemView) {
@@ -91,7 +100,7 @@ abstract class AbstractBrowserTabViewHolder(
         if (selectionHolder != null) {
             setSelectionInteractor(tab, selectionHolder, browserTrayInteractor)
         } else {
-            itemView.setOnClickListener { browserTrayInteractor.open(tab) }
+            itemView.setOnClickListener { browserTrayInteractor.open(tab, featureName) }
         }
 
         if (tab.thumbnail != null) {
@@ -202,12 +211,12 @@ abstract class AbstractBrowserTabViewHolder(
     private fun setSelectionInteractor(
         item: Tab,
         holder: SelectionHolder<Tab>,
-        interactor: SelectionInteractor<Tab>
+        interactor: BrowserTrayInteractor
     ) {
         itemView.setOnClickListener {
             val selected = holder.selectedItems
             when {
-                selected.isEmpty() && trayStore.state.mode.isSelect().not() -> interactor.open(item)
+                selected.isEmpty() && trayStore.state.mode.isSelect().not() -> interactor.open(item, featureName)
                 item in selected -> interactor.deselect(item)
                 else -> interactor.select(item)
             }
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabGridViewHolder.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabGridViewHolder.kt
index 46637def81..5ca700e27c 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabGridViewHolder.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabGridViewHolder.kt
@@ -21,14 +21,22 @@ import org.mozilla.fenix.tabstray.TabsTrayStore
 
 /**
  * A RecyclerView ViewHolder implementation for "tab" items with grid layout.
+ *
+ * @param imageLoader [ImageLoader] used to load tab thumbnails.
+ * @param browserTrayInteractor [BrowserTrayInteractor] handling tabs interactions in a tab tray.
+ * @param store [TabsTrayStore] containing the complete state of tabs tray and methods to update that.
+ * @param selectionHolder [SelectionHolder]<[Tab]> for helping with selecting any number of displayed [Tab]s.
+ * @param itemView [View] that displays a "tab".
+ * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
  */
 class BrowserTabGridViewHolder(
     imageLoader: ImageLoader,
     override val browserTrayInteractor: BrowserTrayInteractor,
     store: TabsTrayStore,
     selectionHolder: SelectionHolder<Tab>? = null,
-    itemView: View
-) : AbstractBrowserTabViewHolder(itemView, imageLoader, store, selectionHolder) {
+    itemView: View,
+    featureName: String
+) : AbstractBrowserTabViewHolder(itemView, imageLoader, store, selectionHolder, featureName) {
 
     private val closeButton: AppCompatImageButton = itemView.findViewById(R.id.mozac_browser_tabstray_close)
 
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabListViewHolder.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabListViewHolder.kt
index da3f13ba8b..9e217c29c2 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabListViewHolder.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabListViewHolder.kt
@@ -15,14 +15,22 @@ import kotlin.math.max
 
 /**
  * A RecyclerView ViewHolder implementation for "tab" items with list layout.
- */
+ *
+ * @param imageLoader [ImageLoader] used to load tab thumbnails.
+ * @param browserTrayInteractor [BrowserTrayInteractor] handling tabs interactions in a tab tray.
+ * @param store [TabsTrayStore] containing the complete state of tabs tray and methods to update that.
+ * @param selectionHolder [SelectionHolder]<[Tab]> for helping with selecting any number of displayed [Tab]s.
+ * @param itemView [View] that displays a "tab".
+ * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
+*/
 class BrowserTabListViewHolder(
     imageLoader: ImageLoader,
     override val browserTrayInteractor: BrowserTrayInteractor,
     store: TabsTrayStore,
     selectionHolder: SelectionHolder<Tab>? = null,
-    itemView: View
-) : AbstractBrowserTabViewHolder(itemView, imageLoader, store, selectionHolder) {
+    itemView: View,
+    featureName: String
+) : AbstractBrowserTabViewHolder(itemView, imageLoader, store, selectionHolder, featureName) {
     override val thumbnailSize: Int
         get() = max(
             itemView.resources.getDimensionPixelSize(R.dimen.tab_tray_list_item_thumbnail_height),
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapter.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapter.kt
index 66199ea5c2..9e89a2123f 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapter.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapter.kt
@@ -17,6 +17,7 @@ import mozilla.components.concept.tabstray.TabsTray
 import mozilla.components.support.base.observer.Observable
 import mozilla.components.support.base.observer.ObserverRegistry
 import org.mozilla.fenix.R
+import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.databinding.TabTrayGridItemBinding
 import org.mozilla.fenix.databinding.TabTrayItemBinding
 import org.mozilla.fenix.ext.components
@@ -25,11 +26,18 @@ import org.mozilla.fenix.tabstray.TabsTrayStore
 
 /**
  * A [RecyclerView.Adapter] for browser tabs.
+ *
+ * @param context [Context] used for various platform interactions or accessing [Components]
+ * @param interactor [BrowserTrayInteractor] handling tabs interactions in a tab tray.
+ * @param store [TabsTrayStore] containing the complete state of tabs tray and methods to update that.
+ * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
+ * @param delegate [Observable]<[TabsTray.Observer]> for observing tabs tray changes. Defaults to [ObserverRegistry].
  */
 class BrowserTabsAdapter(
     private val context: Context,
     private val interactor: BrowserTrayInteractor,
     private val store: TabsTrayStore,
+    private val featureName: String,
     delegate: Observable<TabsTray.Observer> = ObserverRegistry()
 ) : TabsAdapter<AbstractBrowserTabViewHolder>(delegate) {
 
@@ -62,9 +70,9 @@ class BrowserTabsAdapter(
 
         return when (viewType) {
             ViewType.GRID.layoutRes ->
-                BrowserTabGridViewHolder(imageLoader, interactor, store, selectionHolder, view)
+                BrowserTabGridViewHolder(imageLoader, interactor, store, selectionHolder, view, featureName)
             else ->
-                BrowserTabListViewHolder(imageLoader, interactor, store, selectionHolder, view)
+                BrowserTabListViewHolder(imageLoader, interactor, store, selectionHolder, view, featureName)
         }
     }
 
@@ -76,12 +84,12 @@ class BrowserTabsAdapter(
                 ViewType.GRID.layoutRes -> {
                     val gridBinding = TabTrayGridItemBinding.bind(holder.itemView)
                     selectedMaskView = gridBinding.checkboxInclude.selectedMask
-                    gridBinding.mozacBrowserTabstrayClose.setOnClickListener { interactor.close(tab) }
+                    gridBinding.mozacBrowserTabstrayClose.setOnClickListener { interactor.close(tab, featureName) }
                 }
                 ViewType.LIST.layoutRes -> {
                     val listBinding = TabTrayItemBinding.bind(holder.itemView)
                     selectedMaskView = listBinding.checkboxInclude.selectedMask
-                    listBinding.mozacBrowserTabstrayClose.setOnClickListener { interactor.close(tab) }
+                    listBinding.mozacBrowserTabstrayClose.setOnClickListener { interactor.close(tab, featureName) }
                 }
             }
 
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTrayInteractor.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTrayInteractor.kt
index d1c4ad46f9..02c4fc2117 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTrayInteractor.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/BrowserTrayInteractor.kt
@@ -21,10 +21,21 @@ import org.mozilla.fenix.tabstray.TabsTrayStore
  */
 interface BrowserTrayInteractor : SelectionInteractor<Tab>, UserInteractionHandler {
 
+    /**
+     * Open a tab.
+     *
+     * @param tab [Tab] to open in browser.
+     * @param source app feature from which the [tab] was opened.
+     */
+    fun open(tab: Tab, source: String? = null)
+
     /**
      * Close the tab.
+     *
+     * @param tab [Tab] to close.
+     * @param source app feature from which the [tab] was closed.
      */
-    fun close(tab: Tab)
+    fun close(tab: Tab, source: String? = null)
 
     /**
      * TabTray's Floating Action Button clicked.
@@ -65,14 +76,21 @@ class DefaultBrowserTrayInteractor(
      * See [SelectionInteractor.open]
      */
     override fun open(item: Tab) {
-        selectTabWrapper.invoke(item.id)
+        open(item, null)
+    }
+
+    /**
+     * See [BrowserTrayInteractor.open].
+     */
+    override fun open(tab: Tab, source: String?) {
+        selectTabWrapper.invoke(tab.id, source)
     }
 
     /**
      * See [BrowserTrayInteractor.close].
      */
-    override fun close(tab: Tab) {
-        removeTabWrapper.invoke(tab.id)
+    override fun close(tab: Tab, source: String?) {
+        removeTabWrapper.invoke(tab.id, source)
     }
 
     /**
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabViewHolder.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabViewHolder.kt
index 5726b3f34b..68fee1b8e5 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabViewHolder.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabViewHolder.kt
@@ -52,9 +52,17 @@ sealed class InactiveTabViewHolder(itemView: View) : RecyclerView.ViewHolder(ite
         }
     }
 
+    /**
+     * A RecyclerView ViewHolder implementation for an inactive tab view.
+     *
+     * @param itemView the inactive tab [View].
+     * @param browserTrayInteractor [BrowserTrayInteractor] handling tabs interactions in a tab tray.
+     * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
+     */
     class TabViewHolder(
         itemView: View,
-        private val browserTrayInteractor: BrowserTrayInteractor
+        private val browserTrayInteractor: BrowserTrayInteractor,
+        private val featureName: String
     ) : InactiveTabViewHolder(itemView) {
 
         private val binding = InactiveTabListItemBinding.bind(itemView)
@@ -65,7 +73,7 @@ sealed class InactiveTabViewHolder(itemView: View) : RecyclerView.ViewHolder(ite
             val url = tab.url.toShortUrl(components.publicSuffixList).take(MAX_URI_LENGTH)
 
             itemView.setOnClickListener {
-                browserTrayInteractor.open(tab)
+                browserTrayInteractor.open(tab, featureName)
             }
 
             binding.siteListItem.apply {
@@ -75,7 +83,7 @@ sealed class InactiveTabViewHolder(itemView: View) : RecyclerView.ViewHolder(ite
                     R.drawable.mozac_ic_close,
                     R.string.content_description_close_button
                 ) {
-                    browserTrayInteractor.close(tab)
+                    browserTrayInteractor.close(tab, featureName)
                 }
             }
         }
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsAdapter.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsAdapter.kt
index 165f6e3332..cc7e1377f5 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsAdapter.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsAdapter.kt
@@ -13,6 +13,7 @@ import mozilla.components.concept.tabstray.Tab as TabsTrayTab
 import mozilla.components.concept.tabstray.Tabs
 import mozilla.components.concept.tabstray.TabsTray
 import mozilla.components.support.base.observer.ObserverRegistry
+import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.tabstray.browser.InactiveTabViewHolder.FooterHolder
 import org.mozilla.fenix.tabstray.browser.InactiveTabViewHolder.HeaderHolder
 import org.mozilla.fenix.tabstray.browser.InactiveTabViewHolder.RecentlyClosedHolder
@@ -32,10 +33,16 @@ private typealias Observable = ComponentObservable<TabsTray.Observer>
 
 /**
  * The [ListAdapter] for displaying the list of inactive tabs.
+ *
+ * @param context [Context] used for various platform interactions or accessing [Components]
+ * @param browserTrayInteractor [BrowserTrayInteractor] handling tabs interactions in a tab tray.
+ * @param featureName [String] representing the name of the feature displaying tabs. Used in telemetry reporting.
+ * @param delegate [Observable]<[TabsTray.Observer]> for observing tabs tray changes. Defaults to [ObserverRegistry].
  */
 class InactiveTabsAdapter(
     private val context: Context,
     private val browserTrayInteractor: BrowserTrayInteractor,
+    private val featureName: String,
     delegate: Observable = ObserverRegistry()
 ) : Adapter(DiffCallback), TabsTray, Observable by delegate {
 
@@ -47,7 +54,7 @@ class InactiveTabsAdapter(
 
         return when (viewType) {
             HeaderHolder.LAYOUT_ID -> HeaderHolder(view, inactiveTabsInteractor)
-            TabViewHolder.LAYOUT_ID -> TabViewHolder(view, browserTrayInteractor)
+            TabViewHolder.LAYOUT_ID -> TabViewHolder(view, browserTrayInteractor, featureName)
             FooterHolder.LAYOUT_ID -> FooterHolder(view)
             RecentlyClosedHolder.LAYOUT_ID -> RecentlyClosedHolder(view, browserTrayInteractor)
             else -> throw IllegalStateException("Unknown viewType: $viewType")
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsController.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsController.kt
index 16f9e94b65..2658894eee 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsController.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/InactiveTabsController.kt
@@ -8,11 +8,14 @@ import mozilla.components.browser.state.state.TabSessionState
 import mozilla.components.browser.state.store.BrowserStore
 import mozilla.components.concept.tabstray.TabsTray
 import mozilla.components.feature.tabs.ext.toTabs
+import org.mozilla.fenix.components.metrics.MetricController
+import org.mozilla.fenix.components.metrics.Event
 
 class InactiveTabsController(
     private val browserStore: BrowserStore,
     private val tabFilter: (TabSessionState) -> Boolean,
-    private val tray: TabsTray
+    private val tray: TabsTray,
+    private val metrics: MetricController
 ) {
     /**
      * Updates the inactive card to be expanded to display all the tabs, or collapsed with only
@@ -21,6 +24,13 @@ class InactiveTabsController(
     fun updateCardExpansion(isExpanded: Boolean) {
         InactiveTabsState.isExpanded = isExpanded
 
+        metrics.track(
+            when (isExpanded) {
+                true -> Event.TabsTrayInactiveTabsExpanded
+                false -> Event.TabsTrayInactiveTabsCollapsed
+            }
+        )
+
         val tabs = browserStore.state.toTabs { tabFilter.invoke(it) }
 
         tray.updateTabs(tabs)
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/NormalBrowserTrayList.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/NormalBrowserTrayList.kt
index 9e12a46a42..3b4cd2e4eb 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/NormalBrowserTrayList.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/NormalBrowserTrayList.kt
@@ -68,7 +68,7 @@ class NormalBrowserTrayList @JvmOverloads constructor(
         }
         val tabsAdapter = concatAdapter.inactiveTabsAdapter.apply {
             inactiveTabsInteractor = DefaultInactiveTabsInteractor(
-                InactiveTabsController(store, tabFilter, this)
+                InactiveTabsController(store, tabFilter, this, context.components.analytics.metrics)
             )
         }
 
diff --git a/app/src/main/java/org/mozilla/fenix/tabstray/browser/UseCases.kt b/app/src/main/java/org/mozilla/fenix/tabstray/browser/UseCases.kt
index 377453bb86..dbb69d236f 100644
--- a/app/src/main/java/org/mozilla/fenix/tabstray/browser/UseCases.kt
+++ b/app/src/main/java/org/mozilla/fenix/tabstray/browser/UseCases.kt
@@ -13,19 +13,27 @@ class SelectTabUseCaseWrapper(
     private val selectTab: TabsUseCases.SelectTabUseCase,
     private val onSelect: (String) -> Unit
 ) : TabsUseCases.SelectTabUseCase {
-    override fun invoke(tabId: String) {
-        metrics.track(Event.OpenedExistingTab)
+    operator fun invoke(tabId: String, source: String? = null) {
+        metrics.track(Event.OpenedExistingTab(source ?: "unknown"))
         selectTab(tabId)
         onSelect(tabId)
     }
+
+    override fun invoke(tabId: String) {
+        invoke(tabId, null)
+    }
 }
 
 class RemoveTabUseCaseWrapper(
     private val metrics: MetricController,
-    private val onRemove: (String) -> Unit
+    private val onRemove: (String) -> Unit,
 ) : TabsUseCases.RemoveTabUseCase {
-    override fun invoke(tabId: String) {
-        metrics.track(Event.ClosedExistingTab)
+    operator fun invoke(tabId: String, source: String? = null) {
+        metrics.track(Event.ClosedExistingTab(source ?: "unknown"))
         onRemove(tabId)
     }
+
+    override fun invoke(tabId: String) {
+        invoke(tabId, null)
+    }
 }
diff --git a/app/src/test/java/org/mozilla/fenix/components/metrics/GleanMetricsServiceTest.kt b/app/src/test/java/org/mozilla/fenix/components/metrics/GleanMetricsServiceTest.kt
index 3be0067944..12e6170fb9 100644
--- a/app/src/test/java/org/mozilla/fenix/components/metrics/GleanMetricsServiceTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/components/metrics/GleanMetricsServiceTest.kt
@@ -207,12 +207,24 @@ class GleanMetricsServiceTest {
         assertTrue(TabsTray.closed.testHasValue())
 
         assertFalse(TabsTray.openedExistingTab.testHasValue())
-        gleanService.track(Event.OpenedExistingTab)
+        gleanService.track(Event.OpenedExistingTab("Test"))
         assertTrue(TabsTray.openedExistingTab.testHasValue())
+        var events = TabsTray.openedExistingTab.testGetValue()
+        assertEquals(1, events.size)
+        assertEquals("tabs_tray", events[0].category)
+        assertEquals("opened_existing_tab", events[0].name)
+        assertEquals(1, events[0].extra!!.size)
+        assertEquals("Test", events[0].extra!!["source"])
 
         assertFalse(TabsTray.closedExistingTab.testHasValue())
-        gleanService.track(Event.ClosedExistingTab)
+        gleanService.track(Event.ClosedExistingTab("Test"))
         assertTrue(TabsTray.closedExistingTab.testHasValue())
+        events = TabsTray.closedExistingTab.testGetValue()
+        assertEquals(1, events.size)
+        assertEquals("tabs_tray", events[0].category)
+        assertEquals("closed_existing_tab", events[0].name)
+        assertEquals(1, events[0].extra!!.size)
+        assertEquals("Test", events[0].extra!!["source"])
 
         assertFalse(TabsTray.privateModeTapped.testHasValue())
         gleanService.track(Event.TabsTrayPrivateModeTapped)
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolderTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolderTest.kt
index 3adc606014..7dd6ec983b 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolderTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/browser/AbstractBrowserTabViewHolderTest.kt
@@ -44,7 +44,7 @@ class AbstractBrowserTabViewHolderTest {
 
         holder.itemView.performClick()
 
-        verify { interactor.open(any()) }
+        verify { interactor.open(any(), holder.featureName) }
     }
 
     @Test
@@ -65,7 +65,7 @@ class AbstractBrowserTabViewHolderTest {
 
         holder.itemView.performClick()
 
-        verify { interactor.open(any()) }
+        verify { interactor.open(any(), holder.featureName) }
         assertTrue(selectionHolder.invoked)
     }
 
@@ -77,8 +77,9 @@ class AbstractBrowserTabViewHolderTest {
         selectionHolder: SelectionHolder<Tab>?,
         store: BrowserStore,
         metrics: MetricController,
-        override val browserTrayInteractor: BrowserTrayInteractor
-    ) : AbstractBrowserTabViewHolder(itemView, imageLoader, trayStore, selectionHolder, store, metrics) {
+        override val browserTrayInteractor: BrowserTrayInteractor,
+        featureName: String = "Test"
+    ) : AbstractBrowserTabViewHolder(itemView, imageLoader, trayStore, selectionHolder, featureName, store, metrics) {
         override val thumbnailSize: Int
             get() = 30
 
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapterTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapterTest.kt
index b790574a9b..3217584294 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapterTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/browser/BrowserTabsAdapterTest.kt
@@ -30,7 +30,7 @@ class BrowserTabsAdapterTest {
 
     @Test
     fun `WHEN bind with payloads is called THEN update the holder`() {
-        val adapter = BrowserTabsAdapter(context, interactor, store)
+        val adapter = BrowserTabsAdapter(context, interactor, store, "Test")
         val holder = mockk<AbstractBrowserTabViewHolder>(relaxed = true)
 
         adapter.updateTabs(
@@ -53,7 +53,7 @@ class BrowserTabsAdapterTest {
 
     @Test
     fun `WHEN the selection holder is set THEN update the selected tab`() {
-        val adapter = BrowserTabsAdapter(context, interactor, store)
+        val adapter = BrowserTabsAdapter(context, interactor, store, "Test")
         val binding = TabTrayItemBinding.inflate(LayoutInflater.from(testContext))
         val holder = spyk(
             BrowserTabListViewHolder(
@@ -61,7 +61,8 @@ class BrowserTabsAdapterTest {
                 browserTrayInteractor = interactor,
                 store = store,
                 selectionHolder = null,
-                itemView = binding.root
+                itemView = binding.root,
+                featureName = "Test"
             )
         )
         val tab = createTab("tab1")
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/browser/InactiveTabsControllerTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/browser/InactiveTabsControllerTest.kt
index 207f619fa4..7656e20a1e 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/browser/InactiveTabsControllerTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/browser/InactiveTabsControllerTest.kt
@@ -15,6 +15,8 @@ import mozilla.components.concept.tabstray.TabsTray
 import org.junit.Assert.assertEquals
 import mozilla.components.browser.state.state.createTab as createTabState
 import org.junit.Test
+import org.mozilla.fenix.components.metrics.Event
+import org.mozilla.fenix.components.metrics.MetricController
 
 class InactiveTabsControllerTest {
     @Test
@@ -31,7 +33,7 @@ class InactiveTabsControllerTest {
         )
         val tray: TabsTray = mockk(relaxed = true)
         val tabsSlot = slot<Tabs>()
-        val controller = InactiveTabsController(store, filter, tray)
+        val controller = InactiveTabsController(store, filter, tray, mockk(relaxed = true))
 
         controller.updateCardExpansion(true)
 
@@ -40,4 +42,30 @@ class InactiveTabsControllerTest {
         assertEquals(2, tabsSlot.captured.list.size)
         assertEquals("1", tabsSlot.captured.list.first().id)
     }
+
+    @Test
+    fun `WHEN expanded THEN track telemetry event`() {
+        val metrics: MetricController = mockk(relaxed = true)
+        val store = BrowserStore(BrowserState())
+        val controller = InactiveTabsController(
+            store, mockk(relaxed = true), mockk(relaxed = true), metrics
+        )
+
+        controller.updateCardExpansion(true)
+
+        verify { metrics.track(Event.TabsTrayInactiveTabsExpanded) }
+    }
+
+    @Test
+    fun `WHEN collapsed THEN track telemetry event`() {
+        val metrics: MetricController = mockk(relaxed = true)
+        val store = BrowserStore(BrowserState())
+        val controller = InactiveTabsController(
+            store, mockk(relaxed = true), mockk(relaxed = true), metrics
+        )
+
+        controller.updateCardExpansion(false)
+
+        verify { metrics.track(Event.TabsTrayInactiveTabsCollapsed) }
+    }
 }
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/browser/RemoveTabUseCaseWrapperTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/browser/RemoveTabUseCaseWrapperTest.kt
index 022b05bd47..fe594f6be6 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/browser/RemoveTabUseCaseWrapperTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/browser/RemoveTabUseCaseWrapperTest.kt
@@ -16,7 +16,7 @@ class RemoveTabUseCaseWrapperTest {
     val metricController = mockk<MetricController>(relaxed = true)
 
     @Test
-    fun `WHEN invoked THEN metrics, use case and callback are triggered`() {
+    fun `WHEN invoked with no source name THEN metrics with unknown source, use case and callback are triggered`() {
         var actualTabId: String? = null
         val onRemove: (String) -> Unit = { tabId ->
             actualTabId = tabId
@@ -25,7 +25,21 @@ class RemoveTabUseCaseWrapperTest {
 
         wrapper("123")
 
-        verify { metricController.track(Event.ClosedExistingTab) }
+        verify { metricController.track(Event.ClosedExistingTab("unknown")) }
+        assertEquals("123", actualTabId)
+    }
+
+    @Test
+    fun `WHEN invoked with a source name THEN metrics containing the source, use case and callback are triggered`() {
+        var actualTabId: String? = null
+        val onRemove: (String) -> Unit = { tabId ->
+            actualTabId = tabId
+        }
+        val wrapper = RemoveTabUseCaseWrapper(metricController, onRemove)
+
+        wrapper("123", "Test")
+
+        verify { metricController.track(Event.ClosedExistingTab("Test")) }
         assertEquals("123", actualTabId)
     }
 }
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/browser/SelectTabUseCaseWrapperTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/browser/SelectTabUseCaseWrapperTest.kt
index fd0f245746..7e82c3ac94 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/browser/SelectTabUseCaseWrapperTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/browser/SelectTabUseCaseWrapperTest.kt
@@ -17,13 +17,25 @@ class SelectTabUseCaseWrapperTest {
     val selectUseCase: TabsUseCases.SelectTabUseCase = mockk(relaxed = true)
 
     @Test
-    fun `WHEN invoked THEN metrics, use case and callback are triggered`() {
+    fun `WHEN invoked with no source name THEN metrics with unknown source, use case and callback are triggered`() {
         val onSelect: (String) -> Unit = mockk(relaxed = true)
         val wrapper = SelectTabUseCaseWrapper(metricController, selectUseCase, onSelect)
 
         wrapper("123")
 
-        verify { metricController.track(Event.OpenedExistingTab) }
+        verify { metricController.track(Event.OpenedExistingTab("unknown")) }
+        verify { selectUseCase("123") }
+        verify { onSelect("123") }
+    }
+
+    @Test
+    fun `WHEN invoked with a source name THEN metrics, use case and callback are triggered`() {
+        val onSelect: (String) -> Unit = mockk(relaxed = true)
+        val wrapper = SelectTabUseCaseWrapper(metricController, selectUseCase, onSelect)
+
+        wrapper("123", "Test")
+
+        verify { metricController.track(Event.OpenedExistingTab("Test")) }
         verify { selectUseCase("123") }
         verify { onSelect("123") }
     }
diff --git a/app/src/test/java/org/mozilla/fenix/tabstray/viewholders/AbstractBrowserPageViewHolderTest.kt b/app/src/test/java/org/mozilla/fenix/tabstray/viewholders/AbstractBrowserPageViewHolderTest.kt
index aef750d17a..9bbbacbf07 100644
--- a/app/src/test/java/org/mozilla/fenix/tabstray/viewholders/AbstractBrowserPageViewHolderTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/tabstray/viewholders/AbstractBrowserPageViewHolderTest.kt
@@ -28,7 +28,7 @@ class AbstractBrowserPageViewHolderTest {
     val store: TabsTrayStore = TabsTrayStore()
     val interactor = mockk<TabsTrayInteractor>(relaxed = true)
     val browserTrayInteractor = mockk<BrowserTrayInteractor>(relaxed = true)
-    val adapter = BrowserTabsAdapter(testContext, browserTrayInteractor, store)
+    val adapter = BrowserTabsAdapter(testContext, browserTrayInteractor, store, "Test")
 
     @Test
     fun `WHEN tabs inserted THEN show tray`() {