diff --git a/src/app/components/RunningDot.tsx b/src/app/components/RunningDot.tsx
new file mode 100644
index 0000000..2a2a2fd
--- /dev/null
+++ b/src/app/components/RunningDot.tsx
@@ -0,0 +1,17 @@
+"use client";
+
+/** Pulsing dot marking a conversation with an active run. Blue matches
+ * ThreadList's STATUS_COLORS.busy. */
+export function RunningDot({ label }: { label: string }) {
+  return (
+    <span
+      role="status"
+      aria-label={label}
+      title={label}
+      className="relative inline-flex size-2 flex-shrink-0"
+    >
+      <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-blue-500 opacity-75" />
+      <span className="relative inline-flex size-2 rounded-full bg-blue-500" />
+    </span>
+  );
+}