diff --git a/apps/desktop/src/preview/BrowserSession.test.ts b/apps/desktop/src/preview/BrowserSession.test.ts
index e258bb2dfc5..17fa48958a7 100644
--- a/apps/desktop/src/preview/BrowserSession.test.ts
+++ b/apps/desktop/src/preview/BrowserSession.test.ts
@@ -14,6 +14,7 @@ const { fromPartition, sessions } = vi.hoisted(() => ({
       readonly clearCache: ReturnType<typeof vi.fn>;
       readonly clearStorageData: ReturnType<typeof vi.fn>;
       readonly getUserAgent: ReturnType<typeof vi.fn>;
+      readonly setPermissionCheckHandler: ReturnType<typeof vi.fn>;
       readonly setPermissionRequestHandler: ReturnType<typeof vi.fn>;
       readonly setUserAgent: ReturnType<typeof vi.fn>;
     }
@@ -28,6 +29,13 @@ vi.mock("electron", () => ({
 
 import * as BrowserSession from "./BrowserSession.ts";
 
+type PermissionRequestHandler = (
+  webContents: unknown,
+  permission: string,
+  callback: (granted: boolean) => void,
+) => void;
+type PermissionCheckHandler = (webContents: unknown, permission: string) => boolean;
+
 const layer = BrowserSession.layer.pipe(Layer.provide(NodeServices.layer));
 
 describe("BrowserSession", () => {
@@ -39,6 +47,7 @@ describe("BrowserSession", () => {
         clearCache: vi.fn(() => Promise.resolve()),
         clearStorageData: vi.fn(() => Promise.resolve()),
         getUserAgent: vi.fn(() => "Mozilla/5.0 Electron/41.5.0 t3code/0.0.27"),
+        setPermissionCheckHandler: vi.fn(),
         setPermissionRequestHandler: vi.fn(),
         setUserAgent: vi.fn(),
       };
@@ -61,6 +70,35 @@ describe("BrowserSession", () => {
     }).pipe(Effect.provide(layer)),
   );
 
+  it.effect("grants clipboard permissions for previewed pages", () =>
+    Effect.gen(function* () {
+      const browserSessions = yield* BrowserSession.BrowserSession;
+
+      const partition = yield* browserSessions.getPartition("scope-a");
+      yield* browserSessions.getSession("scope-a");
+      const mockSession = sessions.get(partition);
+      assert.isDefined(mockSession);
+
+      assert.strictEqual(mockSession.setPermissionRequestHandler.mock.calls.length, 1);
+      const requestHandler = mockSession.setPermissionRequestHandler.mock
+        .calls[0]?.[0] as PermissionRequestHandler;
+      const requested = new Map<string, boolean>();
+      for (const permission of ["clipboard-read", "clipboard-sanitized-write", "midi"]) {
+        requestHandler(undefined, permission, (granted) => requested.set(permission, granted));
+      }
+      assert.strictEqual(requested.get("clipboard-read"), true);
+      assert.strictEqual(requested.get("clipboard-sanitized-write"), true);
+      assert.strictEqual(requested.get("midi"), false);
+
+      assert.strictEqual(mockSession.setPermissionCheckHandler.mock.calls.length, 1);
+      const checkHandler = mockSession.setPermissionCheckHandler.mock
+        .calls[0]?.[0] as PermissionCheckHandler;
+      assert.strictEqual(checkHandler(undefined, "clipboard-read"), true);
+      assert.strictEqual(checkHandler(undefined, "clipboard-sanitized-write"), true);
+      assert.strictEqual(checkHandler(undefined, "midi"), false);
+    }).pipe(Effect.provide(layer)),
+  );
+
   it.effect("preserves partition scope and the platform failure chain", () => {
     const nativeCause = new Error("native digest failed");
     const platformCause = PlatformError.systemError({
diff --git a/apps/desktop/src/preview/BrowserSession.ts b/apps/desktop/src/preview/BrowserSession.ts
index afa8dafe976..0a35800ce89 100644
--- a/apps/desktop/src/preview/BrowserSession.ts
+++ b/apps/desktop/src/preview/BrowserSession.ts
@@ -11,6 +11,19 @@ import * as SynchronizedRef from "effect/SynchronizedRef";
 
 const PREVIEW_PARTITION_PREFIX = "persist:t3code-preview-";
 
+const ALLOWED_PERMISSIONS = [
+  "clipboard-read",
+  "clipboard-sanitized-write",
+  "notifications",
+  "geolocation",
+] as const;
+const PERMISSION_CHECK_ALLOWLIST: ReadonlySet<string> = new Set(ALLOWED_PERMISSIONS);
+// The request handler can also receive the legacy "clipboard-write" permission name.
+const PERMISSION_REQUEST_ALLOWLIST: ReadonlySet<string> = new Set([
+  ...ALLOWED_PERMISSIONS,
+  "clipboard-write",
+]);
+
 export class BrowserSessionPartitionDerivationError extends Schema.TaggedErrorClass<BrowserSessionPartitionDerivationError>()(
   "BrowserSessionPartitionDerivationError",
   {
@@ -120,9 +133,11 @@ export const make = Effect.gen(function* BrowserSessionMake() {
             .replace(/\s*t3code\/[\d.]+/, "");
           browserSession.setUserAgent(userAgent);
           browserSession.setPermissionRequestHandler((_webContents, permission, callback) => {
-            const allowed = ["clipboard-read", "clipboard-write", "notifications", "geolocation"];
-            callback(allowed.includes(permission));
+            callback(PERMISSION_REQUEST_ALLOWLIST.has(permission));
           });
+          browserSession.setPermissionCheckHandler((_webContents, permission) =>
+            PERMISSION_CHECK_ALLOWLIST.has(permission),
+          );
           const next = new Map(sessions);
           next.set(partition, browserSession);
           return [browserSession, next] as const;