diff --git a/apps/control-station/src/components/MseFmp4WebSocketPlayer.tsx b/apps/control-station/src/components/MseFmp4WebSocketPlayer.tsx
index 374a8cc..278004a 100644
--- a/apps/control-station/src/components/MseFmp4WebSocketPlayer.tsx
+++ b/apps/control-station/src/components/MseFmp4WebSocketPlayer.tsx
@@ -261,6 +261,18 @@ export function MseFmp4WebSocketPlayer({
     });
     activeDiagnosticRef.current = diagnosticLifecycle;
     diagnosticLifecycle.verifyBuild();
+    diagnosticLifecycle.post({
+      eventCode: "live_camera_player_effect_started",
+      streamId: delivery.id,
+      transportEpoch,
+    });
+    if (!recoveryAuthorityIdentity) {
+      diagnosticLifecycle.post({
+        eventCode: "live_camera_playback_authority_missing",
+        streamId: delivery.id,
+        transportEpoch,
+      });
+    }
     const transportIsCurrent = () => cameraTransportCallbackIsCurrent(
       transportEpochRef.current,
       transportEpoch,
@@ -473,6 +485,11 @@ export function MseFmp4WebSocketPlayer({
 
     const onSourceOpen = () => {
       if (!transportIsCurrent() || failed) return;
+      diagnosticLifecycle.post({
+        eventCode: "live_camera_media_source_open",
+        streamId: delivery.id,
+        transportEpoch,
+      });
       try {
         sourceBuffer = mediaSource.addSourceBuffer(mediaType);
       } catch {
@@ -525,6 +542,11 @@ export function MseFmp4WebSocketPlayer({
       socket.binaryType = "arraybuffer";
       socket.addEventListener("open", () => {
         if (!transportIsCurrent() || failed) return;
+        diagnosticLifecycle.post({
+          eventCode: "live_camera_websocket_open",
+          streamId: delivery.id,
+          transportEpoch,
+        });
         startupWatchdog?.armFirstMedia();
         setStatus("buffering");
         setMessage(recovering
diff --git a/apps/control-station/src/core/observation/liveViewerDiagnostics.ts b/apps/control-station/src/core/observation/liveViewerDiagnostics.ts
index d582db0..46b865e 100644
--- a/apps/control-station/src/core/observation/liveViewerDiagnostics.ts
+++ b/apps/control-station/src/core/observation/liveViewerDiagnostics.ts
@@ -7,6 +7,10 @@ export type LiveViewerDiagnosticEventCode =
   | "live_receiver_error"
   | "live_camera_source_projected"
   | "live_camera_window_admitted"
+  | "live_camera_player_effect_started"
+  | "live_camera_playback_authority_missing"
+  | "live_camera_media_source_open"
+  | "live_camera_websocket_open"
   | "live_camera_transport_restart_requested"
   | "live_camera_transport_playing";
 
diff --git a/apps/control-station/test/observationSources.test.mjs b/apps/control-station/test/observationSources.test.mjs
index c0f334a..243e80a 100644
--- a/apps/control-station/test/observationSources.test.mjs
+++ b/apps/control-station/test/observationSources.test.mjs
@@ -203,6 +203,24 @@ test("live camera registers sourceopen before assigning the MSE object URL", asy
   );
 });
 
+test("live camera reports each browser startup boundary without device actions", async () => {
+  const source = await readFile(
+    new URL("../src/components/MseFmp4WebSocketPlayer.tsx", import.meta.url),
+    "utf8",
+  );
+  for (const eventCode of [
+    "live_camera_player_effect_started",
+    "live_camera_playback_authority_missing",
+    "live_camera_media_source_open",
+    "live_camera_websocket_open",
+  ]) {
+    assert.ok(
+      source.includes(`eventCode: "${eventCode}"`),
+      `missing bounded player diagnostic ${eventCode}`,
+    );
+  }
+});
+
 test("recorded observation timeline clamps relative seek time without epoch precision in the UI", () => {
   const range = normalizeTimelineRange({
     min: 0,
diff --git a/src/k1link/web/viewer_diagnostics_api.py b/src/k1link/web/viewer_diagnostics_api.py
index a29e516..a73847d 100644
--- a/src/k1link/web/viewer_diagnostics_api.py
+++ b/src/k1link/web/viewer_diagnostics_api.py
@@ -20,6 +20,10 @@ LiveViewerEventCode = Literal[
     "live_receiver_error",
     "live_camera_source_projected",
     "live_camera_window_admitted",
+    "live_camera_player_effect_started",
+    "live_camera_playback_authority_missing",
+    "live_camera_media_source_open",
+    "live_camera_websocket_open",
     "live_camera_transport_restart_requested",
     "live_camera_transport_playing",
 ]
diff --git a/tests/test_viewer_diagnostics_api.py b/tests/test_viewer_diagnostics_api.py
index a13f2fa..8ba6fd9 100644
--- a/tests/test_viewer_diagnostics_api.py
+++ b/tests/test_viewer_diagnostics_api.py
@@ -247,6 +247,10 @@ def test_live_viewer_diagnostic_endpoint_accepts_only_bounded_events(
     for event_code in (
         "live_camera_source_projected",
         "live_camera_window_admitted",
+        "live_camera_player_effect_started",
+        "live_camera_playback_authority_missing",
+        "live_camera_media_source_open",
+        "live_camera_websocket_open",
     ):
         boundary_event = LiveViewerDiagnosticEvent(
             schema_version="missioncore.live-viewer-diagnostic/v2",
@@ -256,6 +260,12 @@ def test_live_viewer_diagnostic_endpoint_accepts_only_bounded_events(
             viewer_instance_id="00000000-0000-4000-8000-000000000004",
             lifecycle_generation=1,
             stream_id="camera-preview-2",
+            transport_epoch=(
+                1
+                if event_code
+                not in {"live_camera_source_projected", "live_camera_window_admitted"}
+                else None
+            ),
         )
         with caplog.at_level(
             logging.INFO,