diff --git a/next-env.d.ts b/next-env.d.ts
index c4b7818..9edff1c 100644
--- a/next-env.d.ts
+++ b/next-env.d.ts
@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.
diff --git a/src/app/api/video/[id]/route.ts b/src/app/api/video/[id]/route.ts
index 5c94d1f..ff77e7c 100644
--- a/src/app/api/video/[id]/route.ts
+++ b/src/app/api/video/[id]/route.ts
@@ -15,14 +15,22 @@ try {
 }
 
 interface Params {
-  params: {
+  params: Promise<{
     id: string;
-  };
+  }>;
 }
 
 export async function GET(request: Request, ctx: Params) {
   // Next.js 가 params 를 항상 보장하지 않는 상황을 대비해, URL 경로에서 id 를 보완적으로 파싱한다.
-  let id: string | undefined = ctx?.params?.id;
+  let id: string | undefined;
+
+  try {
+    const resolved = await ctx.params;
+    id = resolved?.id;
+  } catch {
+    id = undefined;
+  }
+
   if (!id) {
     try {
       const url = new URL(request.url);
diff --git a/src/app/editor/page.tsx b/src/app/editor/page.tsx
index 5ddf261..c578c5f 100644
--- a/src/app/editor/page.tsx
+++ b/src/app/editor/page.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 import type { CSSProperties, ReactNode } from "react";
-import { Fragment, useEffect, useState } from "react";
+import { Fragment, Suspense, useEffect, useState } from "react";
 import Link from "next/link";
 import { useRouter, useSearchParams } from "next/navigation";
 import { FilePlus2, Trash2, Eye, Pencil, ListChecks, Undo2, Redo2 } from "lucide-react";
@@ -71,6 +71,14 @@ import { PropertiesSidebar } from "./panels/PropertiesSidebar";
 import { EditorCanvas } from "./EditorCanvas";
 
 export default function EditorPage() {
+  return (
+    <Suspense fallback={null}>
+      <EditorPageInner />
+    </Suspense>
+  );
+}
+
+function EditorPageInner() {
   const router = useRouter();
   const searchParams = useSearchParams();
   const blocks = useEditorStore((state) => state.blocks);
diff --git a/tests/api/videoServe.spec.ts b/tests/api/videoServe.spec.ts
new file mode 100644
index 0000000..bee7525
--- /dev/null
+++ b/tests/api/videoServe.spec.ts
@@ -0,0 +1,82 @@
+import "dotenv/config";
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { promises as fs } from "fs";
+import path from "path";
+
+const BASE_URL = "http://localhost";
+
+// /api/video/:id 서브 라우트 TDD
+// - 존재하는 업로드 파일 id 로 GET /api/video/:id 를 호출하면 200 과 비디오 바이트를 반환해야 한다.
+// - 존재하지 않는 id 로 호출하면 404 를 반환해야 한다.
+
+// Prisma 엔진이 실제로 로드되지 않도록 PrismaClient 를 단순 목으로 대체한다.
+vi.mock("@prisma/client", () => {
+  class PrismaClient {
+    asset = {
+      // GET /api/video/:id 에서는 MIME 타입 조회에만 사용되므로, 테스트에서는 null 을 반환한다.
+      findUnique: async () => null,
+    };
+  }
+
+  return { PrismaClient };
+});
+
+describe("/api/video/:id 서브 라우트", () => {
+  const uploadsDir = path.join(process.cwd(), "uploads");
+  let testId: string;
+  let filePath: string;
+
+  beforeEach(async () => {
+    await fs.mkdir(uploadsDir, { recursive: true });
+    testId = `test-video-${Date.now()}`;
+    filePath = path.join(uploadsDir, testId);
+    await fs.writeFile(filePath, Buffer.from("dummy-video-bytes"));
+  });
+
+  afterEach(async () => {
+    try {
+      await fs.unlink(filePath);
+    } catch {
+      // 이미 삭제된 경우는 무시한다.
+    }
+  });
+
+  it("업로드된 비디오 파일이 존재하면 200 과 비디오 바이트를 반환해야 한다", async () => {
+    const { GET: handleGet } = await import("@/app/api/video/[id]/route");
+
+    const requestUrl = `${BASE_URL}/api/video/${testId}`;
+    const res = await handleGet(
+      new Request(requestUrl, {
+        headers: {
+          // Referer 기반 핫링크 방지 로직이 있으므로, 동일 호스트의 referer 를 포함한다.
+          referer: `${BASE_URL}/editor`,
+        },
+      }),
+      // Next 16 타입 정의에서는 context.params 가 Promise 형태이므로, Promise 로 감싼다.
+      { params: Promise.resolve({ id: testId }) } as any,
+    );
+
+    expect(res.status).toBe(200);
+    expect(res.headers.get("Content-Type")).toBe("video/mp4");
+
+    const arrayBuffer = await res.arrayBuffer();
+    const buf = Buffer.from(arrayBuffer);
+    expect(buf.length).toBeGreaterThan(0);
+  });
+
+  it("존재하지 않는 비디오 id 로 요청하면 404 를 반환해야 한다", async () => {
+    const { GET: handleGet } = await import("@/app/api/video/[id]/route");
+
+    const missingId = `missing-${Date.now()}`;
+    const res = await handleGet(
+      new Request(`${BASE_URL}/api/video/${missingId}`, {
+        headers: {
+          referer: `${BASE_URL}/editor`,
+        },
+      }),
+      { params: Promise.resolve({ id: missingId }) } as any,
+    );
+
+    expect(res.status).toBe(404);
+  });
+});
diff --git a/uploads/386e38d1-736e-4dd2-90db-1e80990f9ddc b/uploads/386e38d1-736e-4dd2-90db-1e80990f9ddc
new file mode 100644
index 0000000..87ccacf
--- /dev/null
+++ b/uploads/386e38d1-736e-4dd2-90db-1e80990f9ddc
@@ -0,0 +1 @@
+dummy-video
\ No newline at end of file
diff --git a/uploads/fb58aea5-1c53-4b99-b683-a2d6bee52f37 b/uploads/fb58aea5-1c53-4b99-b683-a2d6bee52f37
new file mode 100644
index 0000000..87ccacf
--- /dev/null
+++ b/uploads/fb58aea5-1c53-4b99-b683-a2d6bee52f37
@@ -0,0 +1 @@
+dummy-video
\ No newline at end of file
diff --git a/uploads/test-image-1764578878778 b/uploads/test-image-1764578878778
new file mode 100644
index 0000000..0cc5db2
--- /dev/null
+++ b/uploads/test-image-1764578878778
@@ -0,0 +1 @@
+dummy-image
\ No newline at end of file
diff --git a/uploads/test-image-1764579185471 b/uploads/test-image-1764579185471
new file mode 100644
index 0000000..0cc5db2
--- /dev/null
+++ b/uploads/test-image-1764579185471
@@ -0,0 +1 @@
+dummy-image
\ No newline at end of file
diff --git a/uploads/test-section-bg-1764578878787 b/uploads/test-section-bg-1764578878787
new file mode 100644
index 0000000..0cc5db2
--- /dev/null
+++ b/uploads/test-section-bg-1764578878787
@@ -0,0 +1 @@
+dummy-image
\ No newline at end of file
diff --git a/uploads/test-section-bg-1764579185620 b/uploads/test-section-bg-1764579185620
new file mode 100644
index 0000000..0cc5db2
--- /dev/null
+++ b/uploads/test-section-bg-1764579185620
@@ -0,0 +1 @@
+dummy-image
\ No newline at end of file
diff --git a/uploads/test-section-bg-video-1764578878873 b/uploads/test-section-bg-video-1764578878873
new file mode 100644
index 0000000..badc796
--- /dev/null
+++ b/uploads/test-section-bg-video-1764578878873
@@ -0,0 +1 @@
+dummy-section-video
\ No newline at end of file
diff --git a/uploads/test-section-bg-video-1764579185705 b/uploads/test-section-bg-video-1764579185705
new file mode 100644
index 0000000..badc796
--- /dev/null
+++ b/uploads/test-section-bg-video-1764579185705
@@ -0,0 +1 @@
+dummy-section-video
\ No newline at end of file
diff --git a/uploads/test-video-1764578878841 b/uploads/test-video-1764578878841
new file mode 100644
index 0000000..87ccacf
--- /dev/null
+++ b/uploads/test-video-1764578878841
@@ -0,0 +1 @@
+dummy-video
\ No newline at end of file
diff --git a/uploads/test-video-1764579185695 b/uploads/test-video-1764579185695
new file mode 100644
index 0000000..87ccacf
--- /dev/null
+++ b/uploads/test-video-1764579185695
@@ -0,0 +1 @@
+dummy-video
\ No newline at end of file
diff --git a/uploads/test-video-poster-1764578878782 b/uploads/test-video-poster-1764578878782
new file mode 100644
index 0000000..7285c92
--- /dev/null
+++ b/uploads/test-video-poster-1764578878782
@@ -0,0 +1 @@
+dummy-poster
\ No newline at end of file
diff --git a/uploads/test-video-poster-1764579185505 b/uploads/test-video-poster-1764579185505
new file mode 100644
index 0000000..7285c92
--- /dev/null
+++ b/uploads/test-video-poster-1764579185505
@@ -0,0 +1 @@
+dummy-poster
\ No newline at end of file