feat(billing): disclose that changing plans on a cancelled subscription resumes it

src/locales/en/main.json

@@ -2637,6 +2637,8 @@
     "downgrade": {
       "title": "Change to {plan} plan?",
       "body": "All other members of this workspace will be immediately removed.",
+      "bodyReactivation": "Your subscription is cancelled. Changing your plan will resume it, and you'll be charged {amount} today.",
+      "bodyRemovalAndReactivation": "All other members of this workspace will be immediately removed. Your subscription is cancelled, so changing your plan will also resume it, and you'll be charged {amount} today.",
       "confirmationPhrase": "I understand",
       "confirmationPrompt": "Type \"{phrase}\" to confirm.",
       "confirm": "Change plan",
@@ -2645,7 +2647,9 @@
       "paymentMethodRequired": "A payment method is required to change plans",
       "paymentPageBlocked": "Couldn't open the payment page — please try again",
       "memberRemovalFailed": "Couldn't remove {email} from the team — some members may already be removed and your plan was not changed",
-      "failedAfterMemberRemoval": "Team members were removed, but the plan change didn't complete — please try again or contact support"
+      "failedAfterMemberRemoval": "Team members were removed, but the plan change didn't complete — please try again or contact support",
+      "reactivationConfirmationRequired": "Please confirm the reactivation charge before continuing",
+      "reactivationAmountChanged": "The charge amount changed since you confirmed it — please review and try again"
     },
     "partnerNodesBalance": "\"Partner Nodes\" Credit Balance",
     "partnerNodesDescription": "For running commercial/proprietary models",
@@ -2898,7 +2902,21 @@
       "confirm": "Confirm",
       "subscribeToPlan": "Subscribe to {plan}",
       "switchToPlan": "Switch to {plan}",
-      "backToAllPlans": "Back to all plans"
+      "backToAllPlans": "Back to all plans",
+      "reactivation": {
+        "title": "Reactivating your subscription",
+        "titleAnnual": "Reactivating your subscription — full year billed today",
+        "upgradeBody": "Your {plan} was set to end on {date}. Upgrading now reactivates it — you'll be charged {amount} today, and it will renew automatically on {nextDate} instead of ending.",
+        "downgradeBody": "Your {plan} was set to end on {date}. Switching to {newPlan} reactivates it — you won't be charged today, but it will now renew automatically on {nextDate} at the new price instead of ending.",
+        "durationChangeBody": "Your {plan} was set to end on {date}. Switching to annual billing reactivates it and charges the full year, {amount}, today. It will then renew annually on {nextDate} instead of ending.",
+        "durationChangeBodyMonthly": "Your {plan} was set to end on {date}. Switching to monthly billing reactivates it — you'll be charged {amount} today, and it will renew automatically on {nextDate} instead of ending.",
+        "confirmButton": "Confirm & reactivate",
+        "confirmButtonWithCharge": "Confirm & reactivate — {amount} today",
+        "checkboxLabel": "I understand I'll be charged {amount} today",
+        "confirmationRequired": "Your subscription is cancelled — please confirm the reactivation charge before continuing",
+        "amountChanged": "The charge amount changed since you confirmed it — please review and try again",
+        "unavailable": "We can't confirm this reactivation right now — please choose your plan again"
+      }
     },
     "success": {
       "allSet": "You're all set",

src/platform/telemetry/types.ts

@@ -611,6 +611,8 @@ type BillingErrorCode =
   | 'missing_checkout_response'
   | 'missing_payment_method_url'
   | 'payment_popup_blocked'
+  | 'reactivation_not_confirmed'
+  | 'reactivation_amount_changed'
 
 export interface BillingFailure {
   failure_category: BillingFailureCategory

src/platform/workspace/api/workspaceApi.test.ts

@@ -448,6 +448,25 @@ describe('workspaceApi', () => {
       expect(result).toEqual(data)
     })
 
+    it('subscribe() sends confirm_reactivation when reactivating a cancelled subscription', async () => {
+      const data = { billing_op_id: 'op-1c', status: 'subscribed' }
+      mockAxiosInstance.post.mockResolvedValue({ data })
+
+      const result = await workspaceApi.subscribe('pro-monthly', {
+        confirmReactivation: true
+      })
+
+      expect(mockAxiosInstance.post).toHaveBeenCalledWith(
+        '/api/billing/subscribe',
+        expect.objectContaining({
+          plan_slug: 'pro-monthly',
+          confirm_reactivation: true
+        }),
+        { headers: AUTH_HEADER }
+      )
+      expect(result).toEqual(data)
+    })
+
     it('cancelSubscription() sends POST with idempotency_key', async () => {
       const data = { billing_op_id: 'op-2', cancel_at: '2026-05-01' }
       mockAxiosInstance.post.mockResolvedValue({ data })

src/platform/workspace/api/workspaceApi.ts

@@ -168,13 +168,16 @@ interface SubscribeRequest {
   /** Required for the per-credit Team plan; selects the slider stop. */
   team_credit_stop_id?: string
   billing_cycle?: SubscribeBillingCycle
+  /** Required to change plans while the current subscription is cancelled; server rejects the change without it. */
+  confirm_reactivation?: boolean
 }
 
 export interface SubscribeOptions {
   returnUrl?: string
   cancelUrl?: string
   teamCreditStopId?: string
   billingCycle?: SubscribeBillingCycle
+  confirmReactivation?: boolean
 }
 
 export interface PreviewSubscribeOptions {
@@ -687,7 +690,8 @@ export const workspaceApi = {
           return_url: options.returnUrl,
           cancel_url: options.cancelUrl,
           team_credit_stop_id: options.teamCreditStopId,
-          billing_cycle: options.billingCycle
+          billing_cycle: options.billingCycle,
+          confirm_reactivation: options.confirmReactivation
         } satisfies SubscribeRequest,
         { headers }
       )

src/platform/workspace/components/SubscriptionTransitionPreviewWorkspace.stories.ts

@@ -0,0 +1,224 @@
+import type { Meta, StoryObj } from '@storybook/vue3-vite'
+
+import type { SubscriptionInfo } from '@/composables/billing/types'
+import { i18n } from '@/i18n'
+import type { PreviewSubscribeResponse } from '@/platform/workspace/api/workspaceApi'
+import { setBillingContextMock } from '@/storybook/mocks/useBillingContext'
+
+import SubscriptionTransitionPreviewWorkspace from './SubscriptionTransitionPreviewWorkspace.vue'
+
+type PreviewPlanInfo = PreviewSubscribeResponse['new_plan']
+
+/**
+ * The reactivation-disclosure banner on the single-plan change preview: a
+ * cancelled-but-not-lapsed subscription resumes silently on any plan change,
+ * so the banner discloses that plus the exact charge (and, above the current
+ * plan's monthly total, a consent checkbox gating the confirm button). The
+ * banner reads `subscription`/`isInitialized` from `useBillingContext`, not
+ * from `previewData`, so each story drives it through the Storybook stub
+ * (`setBillingContextMock`) rather than props.
+ */
+const meta: Meta<typeof SubscriptionTransitionPreviewWorkspace> = {
+  title: 'Components/SubscriptionTransitionPreviewWorkspace',
+  component: SubscriptionTransitionPreviewWorkspace,
+  tags: ['autodocs'],
+  parameters: { layout: 'centered' },
+  decorators: [
+    (story) => ({
+      components: { story },
+      template:
+        '<div class="mx-auto flex h-[680px] w-[460px] flex-col rounded-2xl border border-border-default bg-secondary-background p-12"><story /></div>'
+    })
+  ]
+}
+
+export default meta
+type Story = StoryObj<typeof meta>
+
+const TODAY = '2026-08-01T00:00:00Z'
+// The date the pre-existing cancellation was set to lapse; still active until
+// then, which is what makes a plan change on this subscription a reactivation.
+const CANCEL_DATE = '2026-08-25T00:00:00Z'
+const NEXT_MONTHLY_RENEWAL = '2026-09-01T00:00:00Z'
+const NEXT_ANNUAL_RENEWAL = '2027-08-01T00:00:00Z'
+const NEXT_MONTHLY_AFTER_CANCEL = '2026-09-25T00:00:00Z'
+
+function plan(
+  tier: PreviewPlanInfo['tier'],
+  duration: PreviewPlanInfo['duration'],
+  priceCents: number,
+  periodEnd: string
+): PreviewPlanInfo {
+  return {
+    slug: `${tier.toLowerCase()}-${duration.toLowerCase()}`,
+    tier,
+    duration,
+    price_cents: priceCents,
+    credits_cents: 0,
+    seat_summary: {
+      seat_count: 1,
+      total_cost_cents: priceCents,
+      total_credits_cents: 0
+    },
+    period_end: periodEnd
+  }
+}
+
+function cancelledSubscription(
+  tier: NonNullable<SubscriptionInfo['tier']>,
+  duration: NonNullable<SubscriptionInfo['duration']> = 'MONTHLY'
+): SubscriptionInfo {
+  return {
+    isActive: true,
+    tier,
+    duration,
+    planSlug: `${tier.toLowerCase()}-${duration.toLowerCase()}`,
+    renewalDate: null,
+    endDate: CANCEL_DATE,
+    isCancelled: true,
+    hasFunds: true
+  }
+}
+
+const notCancelledSubscription: SubscriptionInfo = {
+  isActive: true,
+  tier: 'STANDARD',
+  duration: 'MONTHLY',
+  planSlug: 'standard-monthly',
+  renewalDate: NEXT_MONTHLY_RENEWAL,
+  endDate: null,
+  isCancelled: false,
+  hasFunds: true
+}
+
+function story(
+  previewData: PreviewSubscribeResponse,
+  subscription: SubscriptionInfo
+): Story {
+  return {
+    args: { previewData },
+    beforeEach() {
+      // Dates render through both a local Intl formatter and vue-i18n's n(),
+      // so pin the locale rather than inherit the developer's.
+      i18n.global.locale.value = 'en'
+      setBillingContextMock({ subscription })
+    }
+  }
+}
+
+/**
+ * Ordinary upgrade, subscription not cancelled — the reactivation banner
+ * must not leak into a normal plan change.
+ */
+export const NotCancelled: Story = story(
+  {
+    allowed: true,
+    transition_type: 'upgrade',
+    effective_at: TODAY,
+    is_immediate: true,
+    cost_today_cents: 1500,
+    cost_next_period_cents: 3500,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('STANDARD', 'MONTHLY', 2000, NEXT_MONTHLY_RENEWAL),
+    new_plan: plan('CREATOR', 'MONTHLY', 3500, NEXT_MONTHLY_RENEWAL)
+  } satisfies PreviewSubscribeResponse,
+  notCancelledSubscription
+)
+
+/**
+ * Cancelled, immediate upgrade — exact-cents charge ($54.54), guarding the
+ * regression where this path rounded the charge shown to the user.
+ */
+export const ReactivatingUpgrade: Story = story(
+  {
+    allowed: true,
+    transition_type: 'upgrade',
+    effective_at: TODAY,
+    is_immediate: true,
+    cost_today_cents: 5454,
+    cost_next_period_cents: 10_000,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('CREATOR', 'MONTHLY', 3500, CANCEL_DATE),
+    new_plan: plan('PRO', 'MONTHLY', 10_000, NEXT_MONTHLY_RENEWAL)
+  } satisfies PreviewSubscribeResponse,
+  cancelledSubscription('CREATOR')
+)
+
+/**
+ * Cancelled, scheduled downgrade — $0 today. The most important state: no
+ * money moves, so the copy alone must make the reactivation unmissable.
+ */
+export const ReactivatingDowngrade: Story = story(
+  {
+    allowed: true,
+    transition_type: 'downgrade',
+    effective_at: CANCEL_DATE,
+    is_immediate: false,
+    cost_today_cents: 0,
+    cost_next_period_cents: 3500,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('PRO', 'MONTHLY', 10_000, CANCEL_DATE),
+    new_plan: plan('CREATOR', 'MONTHLY', 3500, NEXT_MONTHLY_AFTER_CANCEL)
+  } satisfies PreviewSubscribeResponse,
+  cancelledSubscription('PRO')
+)
+
+/** Cancelled, monthly-to-annual — the full year is billed today. */
+export const ReactivatingMonthlyToAnnual: Story = story(
+  {
+    allowed: true,
+    transition_type: 'duration_change',
+    effective_at: TODAY,
+    is_immediate: true,
+    cost_today_cents: 33_600,
+    cost_next_period_cents: 33_600,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('CREATOR', 'MONTHLY', 3500, CANCEL_DATE),
+    new_plan: plan('CREATOR', 'ANNUAL', 33_600, NEXT_ANNUAL_RENEWAL)
+  } satisfies PreviewSubscribeResponse,
+  cancelledSubscription('CREATOR')
+)
+
+/**
+ * Cancelled, annual-to-monthly — the other cadence direction, which used to
+ * wrongly show the annual copy and now has its own wording.
+ */
+export const ReactivatingAnnualToMonthly: Story = story(
+  {
+    allowed: true,
+    transition_type: 'duration_change',
+    effective_at: TODAY,
+    is_immediate: true,
+    cost_today_cents: 1234,
+    cost_next_period_cents: 3500,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('CREATOR', 'ANNUAL', 33_600, CANCEL_DATE),
+    new_plan: plan('CREATOR', 'MONTHLY', 3500, NEXT_MONTHLY_RENEWAL)
+  } satisfies PreviewSubscribeResponse,
+  cancelledSubscription('CREATOR', 'ANNUAL')
+)
+
+/**
+ * Cancelled, charge above the current plan's monthly total — the consent
+ * checkbox renders and the confirm button stays disabled until it's ticked.
+ */
+export const ReactivatingAboveThreshold: Story = story(
+  {
+    allowed: true,
+    transition_type: 'upgrade',
+    effective_at: TODAY,
+    is_immediate: true,
+    cost_today_cents: 8000,
+    cost_next_period_cents: 10_000,
+    credits_today_cents: 0,
+    credits_next_period_cents: 0,
+    current_plan: plan('STANDARD', 'MONTHLY', 2000, CANCEL_DATE),
+    new_plan: plan('PRO', 'MONTHLY', 10_000, NEXT_MONTHLY_RENEWAL)
+  } satisfies PreviewSubscribeResponse,
+  cancelledSubscription('STANDARD')
+)

src/platform/workspace/components/SubscriptionTransitionPreviewWorkspace.test.ts

@@ -16,6 +16,14 @@ vi.mock('vue-i18n', () => ({
   })
 }))
 
+// Not cancelled: keeps the reactivation banner out of these baseline scenarios.
+vi.mock('@/composables/billing/useBillingContext', () => ({
+  useBillingContext: () => ({
+    subscription: { value: { isCancelled: false, endDate: null } },
+    isInitialized: { value: true }
+  })
+}))
+
 const globalOptions = {
   mocks: { $t: (key: string) => key },
   stubs: {