uhyo · uhyo · Feb 18, 2026 · Feb 18, 2026 · Feb 18, 2026
diff --git a/.gitignore b/.gitignore
@@ -3,5 +3,5 @@ dist
 .turbo
 
 # Playwright
-playwright-report/
+playwright-report*/
 test-results/
diff --git a/packages/static/e2e/fixture-ssr-defer/package.json b/packages/static/e2e/fixture-ssr-defer/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "e2e-fixture-ssr-defer",
+  "private": true,
+  "type": "module",
+  "devDependencies": {
+    "@funstack/static": "workspace:*",
+    "@types/react": "^19.2.14",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^5.1.4",
+    "react": "catalog:",
+    "react-dom": "catalog:",
+    "vite": "catalog:"
+  }
+}
diff --git a/packages/static/e2e/fixture-ssr-defer/src/App.tsx b/packages/static/e2e/fixture-ssr-defer/src/App.tsx
@@ -0,0 +1,13 @@
+import { defer } from "@funstack/static/entries/rsc";
+import DeferredContent from "./DeferredContent";
+
+export default function App() {
+  const deferred = defer(<DeferredContent />, { name: "DeferredContent" });
+  return (
+    <main>
+      <h1>SSR Defer Test</h1>
+      <p data-testid="server-rendered">Server rendered content</p>
+      {deferred}
+    </main>
+  );
+}
diff --git a/packages/static/e2e/fixture-ssr-defer/src/DeferredContent.tsx b/packages/static/e2e/fixture-ssr-defer/src/DeferredContent.tsx
@@ -0,0 +1,3 @@
+export default function DeferredContent() {
+  return <p data-testid="deferred-content">Hello from deferred component</p>;
+}
diff --git a/packages/static/e2e/fixture-ssr-defer/src/root.tsx b/packages/static/e2e/fixture-ssr-defer/src/root.tsx
@@ -0,0 +1,11 @@
+export default function Root({ children }: { children: React.ReactNode }) {
+  return (
+    <html lang="en">
+      <head>
+        <meta charSet="UTF-8" />
+        <title>SSR Defer Test</title>
+      </head>
+      <body>{children}</body>
+    </html>
+  );
+}
diff --git a/packages/static/e2e/fixture-ssr-defer/vite.config.ts b/packages/static/e2e/fixture-ssr-defer/vite.config.ts
@@ -0,0 +1,14 @@
+import funstackStatic from "@funstack/static";
+import react from "@vitejs/plugin-react";
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  plugins: [
+    funstackStatic({
+      root: "./src/root.tsx",
+      app: "./src/App.tsx",
+      ssr: true,
+    }),
+    react(),
+  ],
+});
diff --git a/packages/static/e2e/playwright-dev.config.ts b/packages/static/e2e/playwright-dev.config.ts
@@ -29,6 +29,14 @@ export default defineConfig({
       },
       testMatch: /\/multi-entry\.spec\.ts$/,
     },
+    {
+      name: "ssr-defer-dev",
+      use: {
+        ...devices["Desktop Chrome"],
+        baseURL: "http://localhost:4178",
+      },
+      testMatch: /\/ssr-defer\.spec\.ts$/,
+    },
   ],
 
   webServer: [
@@ -45,5 +53,11 @@ export default defineConfig({
       reuseExistingServer: !process.env.CI,
       timeout: 120000,
     },
+    {
+      command: "cd fixture-ssr-defer && pnpm vite dev --port 4178 --strictPort",
+      url: "http://localhost:4178/@vite/client",
+      reuseExistingServer: !process.env.CI,
+      timeout: 120000,
+    },
   ],
 });
diff --git a/packages/static/e2e/playwright.config.ts b/packages/static/e2e/playwright.config.ts
@@ -29,6 +29,14 @@ export default defineConfig({
       },
       testMatch: /\/multi-entry\.spec\.ts$/,
     },
+    {
+      name: "ssr-defer",
+      use: {
+        ...devices["Desktop Chrome"],
+        baseURL: "http://localhost:4177",
+      },
+      testMatch: /\/ssr-defer\.spec\.ts$/,
+    },
   ],
 
   webServer: [
@@ -46,5 +54,12 @@ export default defineConfig({
       reuseExistingServer: !process.env.CI,
       timeout: 120000,
     },
+    {
+      command:
+        "cd fixture-ssr-defer && pnpm vite build && pnpm dlx serve -p 4177 dist/public",
+      url: "http://localhost:4177",
+      reuseExistingServer: !process.env.CI,
+      timeout: 120000,
+    },
   ],
 });
diff --git a/packages/static/e2e/tests-dev/ssr-defer.spec.ts b/packages/static/e2e/tests-dev/ssr-defer.spec.ts
@@ -0,0 +1,35 @@
+import { expect, test } from "@playwright/test";
+
+const htmlHeaders = { Accept: "text/html" };
+
+test.describe("SSR with defer() (dev server)", () => {
+  test("deferred content is server-rendered in HTML", async ({ request }) => {
+    const response = await request.get("/", { headers: htmlHeaders });
+    expect(response.ok()).toBe(true);
+
+    const html = await response.text();
+
+    // The deferred component's content should be present in SSR HTML
+    expect(html).toContain("Hello from deferred component");
+  });
+
+  test("page renders without errors", async ({ page }) => {
+    const errors: string[] = [];
+
+    page.on("pageerror", (error) => {
+      errors.push(error.message);
+    });
+
+    await page.goto("/");
+
+    await expect(page.locator("h1")).toHaveText("SSR Defer Test");
+    await expect(page.getByTestId("server-rendered")).toHaveText(
+      "Server rendered content",
+    );
+    await expect(page.getByTestId("deferred-content")).toHaveText(
+      "Hello from deferred component",
+    );
+
+    expect(errors).toEqual([]);
+  });
+});
diff --git a/packages/static/e2e/tests/ssr-defer.spec.ts b/packages/static/e2e/tests/ssr-defer.spec.ts
@@ -0,0 +1,33 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("SSR with defer()", () => {
+  test("deferred content is server-rendered in HTML", async ({ request }) => {
+    const response = await request.get("/");
+    expect(response.ok()).toBe(true);
+
+    const html = await response.text();
+
+    // The deferred component's content should be present in SSR HTML
+    expect(html).toContain("Hello from deferred component");
+  });
+
+  test("page renders without errors", async ({ page }) => {
+    const errors: string[] = [];
+
+    page.on("pageerror", (error) => {
+      errors.push(error.message);
+    });
+
+    await page.goto("/");
+
+    await expect(page.locator("h1")).toHaveText("SSR Defer Test");
+    await expect(page.getByTestId("server-rendered")).toHaveText(
+      "Server rendered content",
+    );
+    await expect(page.getByTestId("deferred-content")).toHaveText(
+      "Hello from deferred component",
+    );
+
+    expect(errors).toEqual([]);
+  });
+});
diff --git a/packages/static/src/rsc/entry.tsx b/packages/static/src/rsc/entry.tsx
@@ -81,6 +81,7 @@ async function renderEntryToResponse(
       appEntryMarker: marker,
       build: false,
       ssr: true,
+      deferRegistry,
     });
     timings.push(`ssr;dur=${performance.now() - ssrStart}`);
 
@@ -298,6 +299,7 @@ export async function build() {
       appEntryMarker: marker,
       build: true,
       ssr: ssrEnabled,
+      deferRegistry,
     });
 
     results.push({