diff --git a/apps/desktop/src/app/cron/cron-job-model.test.ts b/apps/desktop/src/app/cron/cron-job-model.test.ts
new file mode 100644
index 000000000000..14873e299877
--- /dev/null
+++ b/apps/desktop/src/app/cron/cron-job-model.test.ts
@@ -0,0 +1,56 @@
+import { describe, expect, it } from 'vitest'
+
+import { cronEditorUpdates, jobIsScriptOnly, validateCronEditor } from './cron-job-model'
+
+describe('jobIsScriptOnly', () => {
+  it('is true when no_agent is set and a script is present', () => {
+    expect(jobIsScriptOnly({ no_agent: true, script: 'echo hi' })).toBe(true)
+  })
+
+  it('is false for agent-backed jobs', () => {
+    expect(jobIsScriptOnly({ no_agent: false, script: 'echo hi' })).toBe(false)
+    expect(jobIsScriptOnly({ no_agent: true, script: '' })).toBe(false)
+    expect(jobIsScriptOnly({ no_agent: true, script: null })).toBe(false)
+  })
+})
+
+describe('validateCronEditor', () => {
+  it('requires prompt and schedule for agent-backed jobs', () => {
+    expect(validateCronEditor({ prompt: '', schedule: '', scriptOnlyJob: false })).toBe('prompt_and_schedule')
+    expect(validateCronEditor({ prompt: '', schedule: '0 9 * * *', scriptOnlyJob: false })).toBe('prompt')
+    expect(validateCronEditor({ prompt: 'go', schedule: '', scriptOnlyJob: false })).toBe('schedule')
+  })
+
+  it('allows an empty prompt when editing a script-only job', () => {
+    expect(validateCronEditor({ prompt: '', schedule: '0 9 * * 1', scriptOnlyJob: true })).toBe(null)
+    expect(validateCronEditor({ prompt: 'optional note', schedule: '0 9 * * 1', scriptOnlyJob: true })).toBe(null)
+  })
+
+  it('still requires schedule for script-only jobs', () => {
+    expect(validateCronEditor({ prompt: '', schedule: '', scriptOnlyJob: true })).toBe('schedule')
+  })
+})
+
+describe('cronEditorUpdates', () => {
+  it('omits prompt when saving a script-only job with an empty prompt', () => {
+    expect(
+      cronEditorUpdates(
+        { deliver: 'local', name: 'Weekly', prompt: '', schedule: '0 9 * * 1' },
+        { scriptOnlyJob: true }
+      )
+    ).toEqual({
+      deliver: 'local',
+      name: 'Weekly',
+      schedule: '0 9 * * 1'
+    })
+  })
+
+  it('includes prompt when the user typed one on a script-only job', () => {
+    expect(
+      cronEditorUpdates(
+        { deliver: 'email', name: 'Weekly', prompt: 'note', schedule: '0 9 * * 1' },
+        { scriptOnlyJob: true }
+      ).prompt
+    ).toBe('note')
+  })
+})
diff --git a/apps/desktop/src/app/cron/cron-job-model.ts b/apps/desktop/src/app/cron/cron-job-model.ts
new file mode 100644
index 000000000000..38d3be879f70
--- /dev/null
+++ b/apps/desktop/src/app/cron/cron-job-model.ts
@@ -0,0 +1,62 @@
+import type { CronJob, CronJobUpdates } from '@/types/hermes'
+
+const asText = (value: unknown): string => (typeof value === 'string' ? value : '')
+
+/** Script-only cron jobs run a shell script on schedule with no LLM prompt. */
+export function jobIsScriptOnly(job: Pick<CronJob, 'no_agent' | 'script'>): boolean {
+  return Boolean(job.no_agent) && Boolean(asText(job.script).trim())
+}
+
+export type CronEditorValidationError = 'prompt' | 'prompt_and_schedule' | 'schedule'
+
+export interface CronEditorValidationInput {
+  prompt: string
+  schedule: string
+  scriptOnlyJob: boolean
+}
+
+export function validateCronEditor(input: CronEditorValidationInput): CronEditorValidationError | null {
+  const trimmedPrompt = input.prompt.trim()
+  const trimmedSchedule = input.schedule.trim()
+
+  if (!trimmedSchedule && !trimmedPrompt && !input.scriptOnlyJob) {
+    return 'prompt_and_schedule'
+  }
+
+  if (!trimmedSchedule) {
+    return 'schedule'
+  }
+
+  if (!input.scriptOnlyJob && !trimmedPrompt) {
+    return 'prompt'
+  }
+
+  return null
+}
+
+export interface CronEditorSaveValues {
+  deliver: string
+  name: string
+  prompt: string
+  schedule: string
+}
+
+/** Build the API update payload, preserving an empty prompt on script-only jobs. */
+export function cronEditorUpdates(
+  values: CronEditorSaveValues,
+  options: { scriptOnlyJob: boolean }
+): CronJobUpdates {
+  const updates: CronJobUpdates = {
+    deliver: values.deliver,
+    name: values.name,
+    schedule: values.schedule.trim()
+  }
+
+  const trimmedPrompt = values.prompt.trim()
+
+  if (!options.scriptOnlyJob || trimmedPrompt) {
+    updates.prompt = trimmedPrompt
+  }
+
+  return updates
+}
diff --git a/apps/desktop/src/app/cron/index.tsx b/apps/desktop/src/app/cron/index.tsx
index a3d229ac5af5..2e9c65d5f5a1 100644
--- a/apps/desktop/src/app/cron/index.tsx
+++ b/apps/desktop/src/app/cron/index.tsx
@@ -55,6 +55,7 @@ import {
 import type { SetStatusbarItemGroup } from '../shell/statusbar-controls'
 
 import { jobState, jobTitle, STATE_DOT } from './job-state'
+import { cronEditorUpdates, jobIsScriptOnly, validateCronEditor } from './cron-job-model'
 
 const DEFAULT_DELIVER = 'local'
 
@@ -396,12 +397,11 @@ export function CronView({ onClose, onOpenSession, setStatusbarItemGroup: _setSt
       updateCronJobs(rows => [...rows, created])
       notify({ kind: 'success', title: c.created, message: truncate(jobTitle(created), 60) })
     } else if (editor.mode === 'edit') {
-      const updated = await updateCronJob(editor.job.id, {
-        prompt: values.prompt,
-        schedule: values.schedule,
-        name: values.name,
-        deliver: values.deliver
-      })
+      const scriptOnlyJob = jobIsScriptOnly(editor.job)
+      const updated = await updateCronJob(
+        editor.job.id,
+        cronEditorUpdates(values, { scriptOnlyJob })
+      )
 
       updateCronJobs(rows => rows.map(row => (row.id === updated.id ? updated : row)))
       notify({ kind: 'success', title: c.updated, message: truncate(jobTitle(updated), 60) })
@@ -712,6 +712,7 @@ function CronEditorDialog({
   const open = editor.mode !== 'closed'
   const isEdit = editor.mode === 'edit'
   const initial = isEdit ? editor.job : null
+  const scriptOnlyJob = initial ? jobIsScriptOnly(initial) : false
 
   const [name, setName] = useState('')
   const [prompt, setPrompt] = useState('')
@@ -755,11 +756,20 @@ function CronEditorDialog({
 
   async function handleSubmit(event: React.FormEvent) {
     event.preventDefault()
-    const trimmedPrompt = prompt.trim()
-    const trimmedSchedule = schedule.trim()
+    const validationError = validateCronEditor({
+      prompt,
+      schedule,
+      scriptOnlyJob
+    })
 
-    if (!trimmedPrompt || !trimmedSchedule) {
-      setError(c.promptScheduleRequired)
+    if (validationError) {
+      setError(
+        validationError === 'schedule'
+          ? c.scheduleRequired
+          : validationError === 'prompt'
+            ? c.promptRequired
+            : c.promptScheduleRequired
+      )
 
       return
     }
@@ -771,8 +781,8 @@ function CronEditorDialog({
       await onSave({
         deliver,
         name: name.trim(),
-        prompt: trimmedPrompt,
-        schedule: trimmedSchedule
+        prompt: prompt.trim(),
+        schedule: schedule.trim()
       })
     } catch (err) {
       setError(err instanceof Error ? err.message : c.failedSave)
@@ -790,6 +800,12 @@ function CronEditorDialog({
         </DialogHeader>
 
         <form className="grid gap-4" onSubmit={handleSubmit}>
+          {scriptOnlyJob && initial && (
+            <FieldHint>
+              {c.scriptOnlyEditHint} <span className="font-mono">{initial.id}</span>
+            </FieldHint>
+          )}
+
           <Field htmlFor="cron-name" label={c.nameLabel} optional optionalLabel={c.optional}>
             <Input
               autoFocus
@@ -800,7 +816,12 @@ function CronEditorDialog({
             />
           </Field>
 
-          <Field htmlFor="cron-prompt" label={c.promptLabel}>
+          <Field
+            htmlFor="cron-prompt"
+            label={c.promptLabel}
+            optional={scriptOnlyJob}
+            optionalLabel={c.optional}
+          >
             <Textarea
               className="min-h-24 font-mono"
               id="cron-prompt"
diff --git a/apps/desktop/src/i18n/en.ts b/apps/desktop/src/i18n/en.ts
index b056bbca5f58..f4837ea8169f 100644
--- a/apps/desktop/src/i18n/en.ts
+++ b/apps/desktop/src/i18n/en.ts
@@ -1470,7 +1470,10 @@ export const en: Translations = {
     customPlaceholder: '0 9 * * * or weekdays at 9am',
     customHint: 'Cron expression, or phrases like "every hour" or "weekdays at 9am".',
     optional: 'Optional',
+    promptRequired: 'Prompt is required.',
     promptScheduleRequired: 'Prompt and schedule are required.',
+    scheduleRequired: 'Schedule is required.',
+    scriptOnlyEditHint: 'Script-only job (no AI prompt). Job id:',
     saveChanges: 'Save changes',
     createAction: 'Create cron'
   },
diff --git a/apps/desktop/src/i18n/ja.ts b/apps/desktop/src/i18n/ja.ts
index 20ff811423b6..bbfa6963cad7 100644
--- a/apps/desktop/src/i18n/ja.ts
+++ b/apps/desktop/src/i18n/ja.ts
@@ -1415,7 +1415,10 @@ export const ja = defineLocale({
     customPlaceholder: '0 9 * * * または weekdays at 9am',
     customHint: 'Cron 式、または「every hour」「weekdays at 9am」のようなフレーズ。',
     optional: '省略可能',
+    promptRequired: 'プロンプトは必須です。',
     promptScheduleRequired: 'プロンプトとスケジュールは必須です。',
+    scheduleRequired: 'スケジュールは必須です。',
+    scriptOnlyEditHint: 'スクリプトのみのジョブ（AI プロンプトなし）。ジョブ ID:',
     saveChanges: '変更を保存',
     createAction: 'Cron を作成'
   },
diff --git a/apps/desktop/src/i18n/types.ts b/apps/desktop/src/i18n/types.ts
index 031f5c78f6d2..917609e7df56 100644
--- a/apps/desktop/src/i18n/types.ts
+++ b/apps/desktop/src/i18n/types.ts
@@ -1204,7 +1204,10 @@ export interface Translations {
     customPlaceholder: string
     customHint: string
     optional: string
+    promptRequired: string
     promptScheduleRequired: string
+    scheduleRequired: string
+    scriptOnlyEditHint: string
     saveChanges: string
     createAction: string
   }
diff --git a/apps/desktop/src/i18n/zh-hant.ts b/apps/desktop/src/i18n/zh-hant.ts
index f58fe80edd54..37ad10e069fc 100644
--- a/apps/desktop/src/i18n/zh-hant.ts
+++ b/apps/desktop/src/i18n/zh-hant.ts
@@ -1368,7 +1368,10 @@ export const zhHant = defineLocale({
     customPlaceholder: '0 9 * * * 或 weekdays at 9am',
     customHint: 'Cron 表達式，或類似「每小時」「工作日上午 9 點」的短語。',
     optional: '選填',
+    promptRequired: '提示詞為必填項目。',
     promptScheduleRequired: '提示詞和排程為必填項目。',
+    scheduleRequired: '排程為必填項目。',
+    scriptOnlyEditHint: '僅腳本任務（無 AI 提示詞）。任務 ID：',
     saveChanges: '儲存變更',
     createAction: '建立排程工作'
   },
diff --git a/apps/desktop/src/i18n/zh.ts b/apps/desktop/src/i18n/zh.ts
index babc9b778d25..dc9524c07c50 100644
--- a/apps/desktop/src/i18n/zh.ts
+++ b/apps/desktop/src/i18n/zh.ts
@@ -1647,7 +1647,10 @@ export const zh: Translations = {
     customPlaceholder: '0 9 * * * 或 weekdays at 9am',
     customHint: 'Cron 表达式，或类似"每小时""工作日上午 9 点"的短语。',
     optional: '可选',
+    promptRequired: '提示词为必填项。',
     promptScheduleRequired: '提示词和排程为必填项。',
+    scheduleRequired: '排程为必填项。',
+    scriptOnlyEditHint: '仅脚本任务（无 AI 提示词）。任务 ID：',
     saveChanges: '保存更改',
     createAction: '创建定时任务'
   },
diff --git a/apps/desktop/src/types/hermes.ts b/apps/desktop/src/types/hermes.ts
index 9133fb4dfbf6..aa527179fb18 100644
--- a/apps/desktop/src/types/hermes.ts
+++ b/apps/desktop/src/types/hermes.ts
@@ -556,6 +556,7 @@ export interface CronJob {
   last_run_at?: null | string
   name?: null | string
   next_run_at?: null | string
+  no_agent?: boolean
   prompt?: null | string
   schedule?: CronJobSchedule
   schedule_display?: null | string