diff --git a/packages/experimental/cua/tests/fixtures/permission-store-worker.ts b/packages/experimental/cua/tests/fixtures/permission-store-worker.ts
index a1b5f6d5ff..5a30c72de6 100644
--- a/packages/experimental/cua/tests/fixtures/permission-store-worker.ts
+++ b/packages/experimental/cua/tests/fixtures/permission-store-worker.ts
@@ -1,26 +1,16 @@
-/** Independent process used to verify fresh authorization reads over the production JSON backend. */
-import { Context } from '@deepseek-ai/cordis'
-import Storage from '@deepseek-ai/dsh-storage'
-import * as JsonStorage from '@deepseek-ai/dsh-storage-json'
-import * as Domains from '@deepseek-ai/dsh-storage-domain'
-import { CuaPermissionStore } from '../../src/permission-store.ts'
-import type { CuaApplicationId } from '../../src/application-types.ts'
+/** External file writer used to verify that an open provider reloads durable authorization. */
+import { readFile, rename, writeFile } from 'node:fs/promises'
 
-const [root, directory, id] = process.argv.slice(2)
-if (!root || !directory || !id) throw new Error('Expected storage root, profile directory and application id')
-const ctx = new Context()
-try {
-  ctx.provide('profileContext', { dir: directory })
-  await ctx.plugin(Storage)
-  await ctx.plugin(JsonStorage, { root })
-  await ctx.plugin(Domains, { backend: 'json' })
-  const store = new CuaPermissionStore(ctx, [], 30_000)
-  await store.withState(new AbortController().signal, async (transaction) => {
-    const existing = transaction.state.applications[id]
-    await transaction.save({ ...transaction.state, applications: { ...transaction.state.applications,
-      [id]: { revoked: (existing?.revoked ?? 0) + 1, sessions: {},
-        always: { id: id as CuaApplicationId, name: 'Other process', executablePath: '/other' } },
-    } })
-  })
-  process.stdout.write('saved\n')
-} finally { await ctx.fiber.dispose() }
+const [file, id] = process.argv.slice(2)
+if (!file || !id) throw new Error('Expected storage file and application id')
+const record = JSON.parse(await readFile(file, 'utf8'))
+const existing = record.global.applications[id]
+record.global.applications[id] = {
+  revoked: (existing?.revoked ?? 0) + 1,
+  sessions: {},
+  always: { id, name: 'Other process', executablePath: '/other' },
+}
+const temporary = `${file}.writer-${process.pid}`
+await writeFile(temporary, JSON.stringify(record))
+await rename(temporary, file)
+process.stdout.write('saved\n')
diff --git a/packages/experimental/cua/tests/permission-store.spec.ts b/packages/experimental/cua/tests/permission-store.spec.ts
index 9f0e176259..4d8c8418d3 100644
--- a/packages/experimental/cua/tests/permission-store.spec.ts
+++ b/packages/experimental/cua/tests/permission-store.spec.ts
@@ -77,8 +77,9 @@ it('reloads another process’s writes instead of reusing an in-memory authoriza
   const f = await setup(), a = await f.open(f.directory, [grant])
   await a.store.withState(signal, transaction => transaction.state)
   const controller = new AbortController()
-  const running = promisify(execFile)(process.execPath, ['--import', 'tsx/esm',
-    fileURLToPath(new URL('./fixtures/permission-store-worker.ts', import.meta.url)), f.storageRoot, f.directory, grant.id,
+  const file = join(f.storageRoot, (await readdir(f.storageRoot))[0]!)
+  const running = promisify(execFile)(process.execPath, [
+    fileURLToPath(new URL('./fixtures/permission-store-worker.ts', import.meta.url)), file, grant.id,
   ], { cwd: process.cwd(), env: { PATH: process.env.PATH }, signal: controller.signal })
   onTestFinished(async () => { controller.abort(); await running.catch(() => {}) })
   expect((await running).stdout).toBe('saved\n')