diff --git a/app/api/client/[token]/annotation/route.ts b/app/api/client/[token]/annotation/route.ts
new file mode 100644
index 0000000..db755a6
--- /dev/null
+++ b/app/api/client/[token]/annotation/route.ts
@@ -0,0 +1,68 @@
+import { NextRequest, NextResponse } from "next/server";
+import { db } from "@/lib/db";
+import { validateReviewToken } from "@/lib/review-auth";
+
+/** Find or create a guest user for the client reviewer based on the session email */
+async function getOrCreateClientUser(email: string, label?: string | null) {
+  const existing = await db.user.findUnique({ where: { email } });
+  if (existing) return existing;
+  return db.user.create({
+    data: {
+      email,
+      name: label ?? email.split("@")[0],
+      role: "CLIENT",
+      isActive: true,
+    },
+  });
+}
+
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ token: string }> }
+) {
+  const { token } = await params;
+  const result = await validateReviewToken(token, req);
+  if (result.type === "requiresPassword") {
+    return NextResponse.json({ requiresPassword: true }, { status: 401 });
+  }
+  if (result.type === "invalid") {
+    return NextResponse.json({ error: "Invalid or expired review link" }, { status: 403 });
+  }
+  const session = result.session;
+
+  const body = await req.json();
+  const { versionId, frameNumber, drawingData, color } = body;
+
+  if (!versionId || frameNumber == null || !drawingData) {
+    return NextResponse.json({ error: "Missing required fields" }, { status: 400 });
+  }
+
+  // Ensure the version belongs to this project
+  const version = await db.version.findUnique({
+    where: { id: versionId },
+    include: {
+      shot: { select: { projectId: true } },
+      task: { select: { projectId: true } },
+    },
+  });
+  const projectId = version?.shot?.projectId ?? version?.task?.projectId;
+  if (!version || projectId !== session.projectId) {
+    return NextResponse.json({ error: "Version not found" }, { status: 404 });
+  }
+
+  // Resolve commenter identity
+  const email = session.email ?? `client+${token.slice(0, 8)}@review.external`;
+  const user = await getOrCreateClientUser(email, session.label);
+
+  const annotation = await db.annotation.create({
+    data: {
+      versionId,
+      authorId: user.id,
+      frameNumber,
+      drawingData,
+      color: color ?? "#ef4444",
+    },
+  });
+
+  return NextResponse.json({ success: true, annotation });
+}
diff --git a/app/client/[token]/review/[versionId]/page.tsx b/app/client/[token]/review/[versionId]/page.tsx
index 6cdf6f3..45a3d13 100644
--- a/app/client/[token]/review/[versionId]/page.tsx
+++ b/app/client/[token]/review/[versionId]/page.tsx
@@ -445,6 +445,23 @@ export default function ClientReviewPage({
             comments={comments as any}
             versionId={version.id}
             onAddComment={handlePlayerAddComment}
+            saveAnnotationFn={async (data) => {
+              const res = await fetch(`/api/client/${token}/annotation`, {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify(data),
+              });
+              if (!res.ok) throw new Error("Failed to save annotation");
+            }}
+            addCommentFn={async (data) => {
+              const res = await fetch(`/api/client/${token}/comment`, {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify(data),
+              });
+              if (!res.ok) throw new Error("Failed to post comment");
+              await refreshComments(token, version.id);
+            }}
           />
         </div>
 
diff --git a/components/annotations/AnnotationCanvas.tsx b/components/annotations/AnnotationCanvas.tsx
index 994da22..d343d2c 100644
--- a/components/annotations/AnnotationCanvas.tsx
+++ b/components/annotations/AnnotationCanvas.tsx
@@ -14,6 +14,20 @@ import { useToast } from "@/components/ui/use-toast";
 import type { AnnotationShape, AnnotationDrawingData, AnnotationPoint } from "@/types";
 import { v4 as uuidv4 } from "uuid";
 
+interface SaveAnnotationData {
+  versionId: string;
+  frameNumber: number;
+  drawingData: AnnotationDrawingData;
+  color: string;
+}
+
+interface AddCommentData {
+  versionId: string;
+  frameNumber: number;
+  timestamp: number;
+  text: string;
+}
+
 interface AnnotationCanvasProps {
   versionId: string;
   frameNumber: number;
@@ -22,6 +36,10 @@ interface AnnotationCanvasProps {
   showAnnotations: boolean;
   existingAnnotations?: unknown[];
   onAnnotationSaved?: (frameNumber: number) => void;
+  /** Override the default server action used to persist annotations (e.g. for client-token routes) */
+  saveAnnotationFn?: (data: SaveAnnotationData) => Promise<void>;
+  /** Override the default server action used to create the companion comment */
+  addCommentFn?: (data: AddCommentData) => Promise<void>;
 }
 
 type DrawingState = {
@@ -38,6 +56,8 @@ export function AnnotationCanvas({
   showAnnotations,
   existingAnnotations = [],
   onAnnotationSaved,
+  saveAnnotationFn,
+  addCommentFn,
 }: AnnotationCanvasProps) {
   const canvasRef = useRef<HTMLCanvasElement>(null);
   const { selectedTool, selectedColor, strokeWidth } = useReviewStore();
@@ -334,7 +354,16 @@ export function AnnotationCanvas({
         canvasHeight: canvas?.offsetHeight ?? 1080,
         version: "1.0",
       };
-      await saveAnnotation({
+
+      const doSaveAnnotation = saveAnnotationFn
+        ? saveAnnotationFn
+        : (data: SaveAnnotationData) => saveAnnotation(data).then(() => undefined);
+
+      const doAddComment = addCommentFn
+        ? addCommentFn
+        : (data: AddCommentData) => addComment(data).then(() => undefined);
+
+      await doSaveAnnotation({
         versionId,
         frameNumber,
         drawingData,
@@ -344,7 +373,7 @@ export function AnnotationCanvas({
       // Create a companion comment ONCE per frame so the annotation appears in the panel.
       // Additional strokes on the same frame update the existing comment count silently.
       if (!annotationCommentedFrames.has(frameNumber)) {
-        await addComment({
+        await doAddComment({
           versionId,
           frameNumber,
           timestamp: frameNumber / fps,
@@ -360,7 +389,7 @@ export function AnnotationCanvas({
         variant: "destructive",
       });
     }
-  }, [versionId, frameNumber, fps, selectedColor, annotationCommentedFrames, onAnnotationSaved, toast]);
+  }, [versionId, frameNumber, fps, selectedColor, annotationCommentedFrames, onAnnotationSaved, toast, saveAnnotationFn, addCommentFn]);
 
   // ── Touch events (mirrors mouse events for mobile drawing) ──────────────
   const handleTouchStart = useCallback(
diff --git a/components/player/ReviewPlayer.tsx b/components/player/ReviewPlayer.tsx
index c96a3ee..2780829 100644
--- a/components/player/ReviewPlayer.tsx
+++ b/components/player/ReviewPlayer.tsx
@@ -33,6 +33,10 @@ interface ReviewPlayerProps {
   className?: string;
   onAddComment?: (frameNumber: number, timestamp: number) => void;
   onAnnotationSaved?: (frameNumber: number) => void;
+  /** Override the default server action used to persist annotations (e.g. for client-token routes) */
+  saveAnnotationFn?: (data: { versionId: string; frameNumber: number; drawingData: unknown; color: string }) => Promise<void>;
+  /** Override the default server action used to create the companion comment */
+  addCommentFn?: (data: { versionId: string; frameNumber: number; timestamp: number; text: string }) => Promise<void>;
 }
 
 export const ReviewPlayer = forwardRef<ReviewPlayerRef, ReviewPlayerProps>(
@@ -46,6 +50,8 @@ export const ReviewPlayer = forwardRef<ReviewPlayerRef, ReviewPlayerProps>(
       className,
       onAddComment,
       onAnnotationSaved,
+      saveAnnotationFn,
+      addCommentFn,
     },
     ref
   ) {
@@ -276,6 +282,8 @@ export const ReviewPlayer = forwardRef<ReviewPlayerRef, ReviewPlayerProps>(
             showAnnotations={showAnnotations}
             existingAnnotations={stableAnnotations}
             onAnnotationSaved={onAnnotationSaved}
+            saveAnnotationFn={saveAnnotationFn as any}
+            addCommentFn={addCommentFn}
           />
 
           {/* JKL hint overlay — shown briefly when reversing */}