diff --git a/apps/pwa/src/api/client.ts b/apps/pwa/src/api/client.ts
index 145816e..3776144 100644
--- a/apps/pwa/src/api/client.ts
+++ b/apps/pwa/src/api/client.ts
@@ -131,6 +131,14 @@ export interface CalendarOccurrence {
    * stay in sync with the server type (Pitfall 4 — atomic mirror, Plan 06-05).
    */
   hasRrule: boolean;
+  /**
+   * Per-event reminder lead in minutes. NULL = no reminder. 0 = same-day all-day
+   * (fire 9 AM on event date). Positive integer = N minutes before event start.
+   * D-06: NULL and 0 are semantically distinct.
+   * Mirrors CalendarOccurrence.reminderLeadMinutes in apps/api/src/broker/expand.ts
+   * (atomic mirror, Plan 11-03).
+   */
+  reminderLeadMinutes: number | null;
 }
 
 export interface OccurrencesResponse {
@@ -194,6 +202,14 @@ export interface CreateEventPayload {
   recurrenceCount?: number;
   location?: string;
   description?: string;
+  /**
+   * Per-event reminder lead in minutes.
+   * absent/undefined = no-change (edit omits field so server preserves existing VALARM, D-08)
+   * null             = explicit "None" (clear any VALARM)
+   * 0                = same-day all-day (fire 9 AM on event date, D-05)
+   * positive integer = N minutes before event start
+   */
+  reminderLeadMinutes?: number | null;
   calendarUrl?: string; // omit to use the member's default writable calendar (D-01)
 }
 
diff --git a/apps/pwa/src/components/EventDetailPopover.test.tsx b/apps/pwa/src/components/EventDetailPopover.test.tsx
index a5ac191..65dc7ac 100644
--- a/apps/pwa/src/components/EventDetailPopover.test.tsx
+++ b/apps/pwa/src/components/EventDetailPopover.test.tsx
@@ -59,6 +59,7 @@ const TIMED_OCCURRENCE: CalendarOccurrence = {
   location: 'Conference Room B',
   description: 'Daily team sync meeting',
   hasRrule: false,
+  reminderLeadMinutes: null,
 };
 
 const OCCURRENCE_WITH_HTML: CalendarOccurrence = {
@@ -86,6 +87,7 @@ const ALLDAY_OCCURRENCE: CalendarOccurrence = {
   location: null,
   description: null,
   hasRrule: false,
+  reminderLeadMinutes: null,
 };
 
 // ── Import component (after mocks are declared) ───────────────────────────────
diff --git a/apps/pwa/src/components/EventForm.test.tsx b/apps/pwa/src/components/EventForm.test.tsx
index dae8039..b65033d 100644
--- a/apps/pwa/src/components/EventForm.test.tsx
+++ b/apps/pwa/src/components/EventForm.test.tsx
@@ -124,6 +124,7 @@ const EDIT_OCCURRENCE: CalendarOccurrence = {
   location: 'Office',
   description: 'Weekly sync',
   hasRrule: false,
+  reminderLeadMinutes: null,
 };
 
 // ── Import component (after mocks) ────────────────────────────────────────────
@@ -506,6 +507,7 @@ const RECURRING_OCCURRENCE: CalendarOccurrence = {
   location: null,
   description: null,
   hasRrule: true,
+  reminderLeadMinutes: null,
   // @ts-expect-error — recurrence is not on CalendarOccurrence type yet; the reset
   // effect reads it if present and defaults to 'none' when absent (WR-03, v1 comment)
   recurrence: 'weekly',
@@ -532,6 +534,7 @@ const LATE_OCCURRENCE: CalendarOccurrence = {
   location: null,
   description: null,
   hasRrule: false,
+  reminderLeadMinutes: null,
 };
 
 describe('EventForm — Plan 03-12 gap closures', () => {
@@ -779,6 +782,7 @@ const ALL_DAY_OCCURRENCE: CalendarOccurrence = {
   location: null,
   description: null,
   hasRrule: false,
+  reminderLeadMinutes: null,
 };
 
 describe('EventForm — Plan 06-06 end-tracking + recurrence-bound', () => {