diff --git a/src/lib/api/client.ts b/src/lib/api/client.ts
index 11aa0b5..76b982e 100644
--- a/src/lib/api/client.ts
+++ b/src/lib/api/client.ts
@@ -1,4 +1,4 @@
-import type { components } from './schema';
+import type { components, operations } from './schema';
 
 export type AuthSession = components['schemas']['AuthSession'];
 export type ReportingPeriod = components['schemas']['ReportingPeriod'];
@@ -12,6 +12,8 @@ export type DetailView = components['schemas']['DetailView'];
 export type FailureStage = components['schemas']['FailureStage'];
 export type Problem = components['schemas']['Problem'];
 export type GrowthReport = components['schemas']['GrowthReport'];
+export type CreateGrowthReportRequest =
+  operations['createGrowthReport']['requestBody']['content']['application/json'];
 
 const apiBase = (import.meta.env.PUBLIC_API_BASE_URL || '/api/v1').replace(/\/$/, '');
 
@@ -124,7 +126,7 @@ export const api = {
     const query = terminalId ? `?terminalId=${encodeURIComponent(terminalId)}` : '';
     return request<GrowthReport>(`/analytics/growth-reports/latest${query}`);
   },
-  createGrowthReport(csrfToken: string, options: { terminalId?: string; refresh?: boolean } = {}) {
+  createGrowthReport(csrfToken: string, options: CreateGrowthReportRequest = {}) {
     return request<GrowthReport>('/analytics/growth-reports', {
       method: 'POST',
       headers: {
diff --git a/src/lib/api/growth-client.test.ts b/src/lib/api/growth-client.test.ts
index 06a33e6..fb19833 100644
--- a/src/lib/api/growth-client.test.ts
+++ b/src/lib/api/growth-client.test.ts
@@ -53,4 +53,19 @@ describe('growth report API client', () => {
     expect(init.headers['Idempotency-Key']).toBe('idempotency-1');
     expect(JSON.parse(init.body)).toEqual({ terminalId: 'terminal-1', refresh: true });
   });
+
+  it('creates a report with an empty request when optional fields are omitted', async () => {
+    const fetchMock = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify(report), {
+        status: 200,
+        headers: { 'Content-Type': 'application/json' },
+      }),
+    );
+    vi.stubGlobal('fetch', fetchMock);
+    vi.stubGlobal('crypto', { randomUUID: () => 'idempotency-2' });
+
+    await api.createGrowthReport('csrf-2');
+
+    expect(JSON.parse(fetchMock.mock.calls[0][1].body)).toEqual({});
+  });
 });
diff --git a/src/lib/api/schema.d.ts b/src/lib/api/schema.d.ts
index 0713585..04502de 100644
--- a/src/lib/api/schema.d.ts
+++ b/src/lib/api/schema.d.ts
@@ -337,8 +337,8 @@ export interface components {
   schemas: {
     CreateGrowthReportRequest: {
       terminalId?: string;
-      /** @default false */
-      refresh: boolean;
+      /** @description When omitted, the request reuses the current matching report. */
+      refresh?: boolean;
     };
     GrowthRange: {
       /** Format: int64 */