diff --git a/apps/vscode/src/core/controller/ui/initializeWebview.ts b/apps/vscode/src/core/controller/ui/initializeWebview.ts
index f095f29f90..7fd665f3f3 100644
--- a/apps/vscode/src/core/controller/ui/initializeWebview.ts
+++ b/apps/vscode/src/core/controller/ui/initializeWebview.ts
@@ -20,6 +20,11 @@ import { refreshOpenRouterModels } from "../models/refreshOpenRouterModels"
  */
 export async function initializeWebview(controller: Controller, _request: EmptyRequest): Promise<Empty> {
 	try {
+		// The webview calls this once on mount, on every host. The VS Code-only
+		// "sidebar_resolved"/"sidebar_visible" sources never fire for JetBrains, so
+		// this is the only host-neutral signal that the Cline UI actually rendered.
+		telemetryService.capturePanelOpened("webview_initialized")
+
 		// Sync workflow toggles with the files on disk so the chat input's slash
 		// command menu knows about workflows without requiring the user to open
 		// the Workflows modal first (which is the only other place that refreshes
diff --git a/apps/vscode/src/services/telemetry/TelemetryService.ts b/apps/vscode/src/services/telemetry/TelemetryService.ts
index 21d51738df..222416a4f7 100644
--- a/apps/vscode/src/services/telemetry/TelemetryService.ts
+++ b/apps/vscode/src/services/telemetry/TelemetryService.ts
@@ -92,6 +92,13 @@ export enum TerminalHangStage {
 	BUFFER_STUCK = "buffer_stuck",
 }
 
+/**
+ * Which hook fired `ui.panel_opened`. "sidebar_resolved" / "sidebar_visible" come from
+ * VscodeWebviewProvider and are VS Code-only; "webview_initialized" comes from the webview's
+ * mount-time initializeWebview RPC and fires on every host.
+ */
+export type PanelOpenedSource = "sidebar_resolved" | "sidebar_visible" | "webview_initialized"
+
 export type TelemetryMetadata = {
 	/**
 	 * The extension or cline-core version. JetBrains and CLI have different
@@ -328,7 +335,9 @@ export class TelemetryService {
 			MODEL_FAVORITE_TOGGLED: "ui.model_favorite_toggled",
 			// Tracks when a button is clicked
 			BUTTON_CLICKED: "ui.button_clicked",
-			// Tracks when the Cline panel becomes visible
+			// Tracks when the Cline panel becomes visible; `source` (PanelOpenedSource) says
+			// which hook fired. On JetBrains "webview_initialized" also fires on every webview
+			// reload, e.g. after a core restart, so a crash-restart loop emits one per restart.
 			PANEL_OPENED: "ui.panel_opened",
 			// Tracks when the user explicitly starts a new task flow
 			NEW_TASK_CLICKED: "ui.new_task_clicked",
@@ -944,7 +953,7 @@ export class TelemetryService {
 		})
 	}
 
-	public capturePanelOpened(source?: string) {
+	public capturePanelOpened(source: PanelOpenedSource) {
 		this.capture({
 			event: TelemetryService.EVENTS.UI.PANEL_OPENED,
 			properties: { source },