diff --git a/frontend/src/api/billing.ts b/frontend/src/api/billing.ts
index 96b9e21..f21a335 100644
--- a/frontend/src/api/billing.ts
+++ b/frontend/src/api/billing.ts
@@ -61,7 +61,7 @@ export async function deleteInvoice(id: string): Promise<void> {
 }
 
 export async function downloadInvoicePdf(id: string): Promise<void> {
-  const res = await api.get(`/billing/invoices/${id}/pdf`, { responseType: 'blob' })
+  const res = await api.get<Blob>(`/billing/invoices/${id}/pdf`, { responseType: 'blob' })
   const url = URL.createObjectURL(res.data)
   const a = document.createElement('a')
   a.href = url
diff --git a/frontend/src/api/cad.ts b/frontend/src/api/cad.ts
index b73e34d..797f6a8 100644
--- a/frontend/src/api/cad.ts
+++ b/frontend/src/api/cad.ts
@@ -100,6 +100,6 @@ export async function generateGltfProduction(cadFileId: string): Promise<Generat
 
 /** Force-reset a CAD file stuck in 'processing' to 'failed'. */
 export async function resetStuckProcessing(cadFileId: string): Promise<{ status: string; message: string }> {
-  const res = await api.post(`/cad/${cadFileId}/reset-stuck`)
+  const res = await api.post<{ status: string; message: string }>(`/cad/${cadFileId}/reset-stuck`)
   return res.data
 }
diff --git a/frontend/src/api/imports.ts b/frontend/src/api/imports.ts
index 10affb8..69dec25 100644
--- a/frontend/src/api/imports.ts
+++ b/frontend/src/api/imports.ts
@@ -14,7 +14,7 @@ export interface ImportValidation {
 }
 
 export async function getImportValidation(id: string): Promise<ImportValidation> {
-  const res = await api.get(`/imports/validation/${id}`)
+  const res = await api.get<ImportValidation>(`/imports/validation/${id}`)
   return res.data
 }
 
diff --git a/frontend/src/api/materials.ts b/frontend/src/api/materials.ts
index 32d84e5..d883cff 100644
--- a/frontend/src/api/materials.ts
+++ b/frontend/src/api/materials.ts
@@ -47,7 +47,10 @@ export async function saveCadPartMaterials(
   itemId: string,
   parts: Array<{ part_name: string; material: string }>,
 ) {
-  const res = await api.put(`/orders/${orderId}/items/${itemId}/cad-materials`, { parts })
+  const res = await api.put<{ parts: Array<{ part_name: string; material: string }> }>(
+    `/orders/${orderId}/items/${itemId}/cad-materials`,
+    { parts },
+  )
   return res.data
 }
 
diff --git a/frontend/src/api/notifications.ts b/frontend/src/api/notifications.ts
index 1fd0621..fd49ccb 100644
--- a/frontend/src/api/notifications.ts
+++ b/frontend/src/api/notifications.ts
@@ -25,12 +25,12 @@ export async function getNotifications(params?: {
   unread_only?: boolean
   channel?: NotificationChannel
 }): Promise<NotificationListResponse> {
-  const { data } = await api.get('/notifications', { params })
+  const { data } = await api.get<NotificationListResponse>('/notifications', { params })
   return data
 }
 
 export async function getUnreadCount(): Promise<number> {
-  const { data } = await api.get('/notifications/unread-count')
+  const { data } = await api.get<{ unread_count: number }>('/notifications/unread-count')
   return data.unread_count
 }
 
diff --git a/frontend/src/api/orders.ts b/frontend/src/api/orders.ts
index f0fd55e..abefa20 100644
--- a/frontend/src/api/orders.ts
+++ b/frontend/src/api/orders.ts
@@ -46,6 +46,8 @@ export interface Order {
   updated_at: string
   submitted_at: string | null
   completed_at: string | null
+  rejected_at: string | null
+  rejection_reason: string | null
   estimated_price: number | null
   item_count: number
   line_count: number
@@ -239,8 +241,21 @@ export async function generateLinesFromItems(
   return res.data
 }
 
+export async function rejectOrder(orderId: string, reason: string, notifyClient: boolean = true): Promise<Order> {
+  const res = await api.post<Order>(`/orders/${orderId}/reject`, {
+    reason,
+    notify_client: notifyClient,
+  })
+  return res.data
+}
+
+export async function resubmitOrder(orderId: string): Promise<Order> {
+  const res = await api.post<Order>(`/orders/${orderId}/resubmit`)
+  return res.data
+}
+
 export async function downloadOrderRenders(orderId: string, orderNumber: string): Promise<void> {
-  const res = await api.get(`/orders/${orderId}/download-renders`, { responseType: 'blob' })
+  const res = await api.get<Blob>(`/orders/${orderId}/download-renders`, { responseType: 'blob' })
   const url = URL.createObjectURL(res.data)
   const a = document.createElement('a')
   a.href = url
diff --git a/frontend/src/api/products.ts b/frontend/src/api/products.ts
index f4dd03d..099cd73 100644
--- a/frontend/src/api/products.ts
+++ b/frontend/src/api/products.ts
@@ -1,4 +1,5 @@
 import api from './client'
+import type { Order } from './orders'
 
 export interface RenderPosition {
   id: string
@@ -106,10 +107,18 @@ export async function deleteProduct(id: string, hard = false): Promise<void> {
   await api.delete(`/products/${id}`, { params: hard ? { hard: true } : undefined })
 }
 
-export async function uploadProductCad(id: string, file: File) {
+export interface ProductCadUploadResponse {
+  cad_file_id: string
+  original_name: string
+  file_hash: string
+  status: string
+  product_id: string
+}
+
+export async function uploadProductCad(id: string, file: File): Promise<ProductCadUploadResponse> {
   const form = new FormData()
   form.append('file', file)
-  const res = await api.post(`/products/${id}/cad`, form, {
+  const res = await api.post<ProductCadUploadResponse>(`/products/${id}/cad`, form, {
     headers: { 'Content-Type': 'multipart/form-data' },
   })
   return res.data
@@ -120,13 +129,13 @@ export async function saveProductCadMaterials(id: string, parts: CadPartMaterial
   return res.data
 }
 
-export async function regenerateProduct(id: string) {
-  const res = await api.post(`/products/${id}/regenerate`)
+export async function regenerateProduct(id: string): Promise<{ status: string; task_id: string | null }> {
+  const res = await api.post<{ status: string; task_id: string | null }>(`/products/${id}/regenerate`)
   return res.data
 }
 
-export async function reprocessProduct(id: string) {
-  const res = await api.post(`/products/${id}/reprocess`)
+export async function reprocessProduct(id: string): Promise<{ status: string; task_id: string | null }> {
+  const res = await api.post<{ status: string; task_id: string | null }>(`/products/${id}/reprocess`)
   return res.data
 }
 
@@ -174,8 +183,8 @@ export async function downloadProductRenders(
   URL.revokeObjectURL(url)
 }
 
-export async function getProductOrders(id: string) {
-  const res = await api.get(`/products/${id}/orders`)
+export async function getProductOrders(id: string): Promise<Order[]> {
+  const res = await api.get<Order[]>(`/products/${id}/orders`)
   return res.data
 }
 
diff --git a/frontend/src/api/renderTemplates.ts b/frontend/src/api/renderTemplates.ts
index f5cd4d1..ab948ad 100644
--- a/frontend/src/api/renderTemplates.ts
+++ b/frontend/src/api/renderTemplates.ts
@@ -28,12 +28,12 @@ export interface MaterialLibraryInfo {
 }
 
 export async function listRenderTemplates(): Promise<RenderTemplate[]> {
-  const { data } = await api.get('/render-templates');
+  const { data } = await api.get<RenderTemplate[]>('/render-templates');
   return data;
 }
 
 export async function createRenderTemplate(formData: FormData): Promise<RenderTemplate> {
-  const { data } = await api.post('/render-templates', formData, {
+  const { data } = await api.post<RenderTemplate>('/render-templates', formData, {
     headers: { 'Content-Type': 'multipart/form-data' },
   });
   return data;
@@ -43,7 +43,7 @@ export async function updateRenderTemplate(
   id: string,
   updates: Partial<Pick<RenderTemplate, 'name' | 'category_key' | 'output_type_ids' | 'target_collection' | 'material_replace_enabled' | 'lighting_only' | 'shadow_catcher_enabled' | 'camera_orbit' | 'is_active'>>,
 ): Promise<RenderTemplate> {
-  const { data } = await api.patch(`/render-templates/${id}`, updates);
+  const { data } = await api.patch<RenderTemplate>(`/render-templates/${id}`, updates);
   return data;
 }
 
@@ -54,7 +54,7 @@ export async function deleteRenderTemplate(id: string): Promise<void> {
 export async function reuploadBlendFile(id: string, file: File): Promise<RenderTemplate> {
   const fd = new FormData();
   fd.append('file', file);
-  const { data } = await api.post(`/render-templates/${id}/upload`, fd, {
+  const { data } = await api.post<RenderTemplate>(`/render-templates/${id}/upload`, fd, {
     headers: { 'Content-Type': 'multipart/form-data' },
   });
   return data;
@@ -63,14 +63,14 @@ export async function reuploadBlendFile(id: string, file: File): Promise<RenderT
 export async function uploadMaterialLibrary(file: File): Promise<MaterialLibraryInfo> {
   const fd = new FormData();
   fd.append('file', file);
-  const { data } = await api.post('/admin/settings/material-library', fd, {
+  const { data } = await api.post<MaterialLibraryInfo>('/admin/settings/material-library', fd, {
     headers: { 'Content-Type': 'multipart/form-data' },
   });
   return data;
 }
 
 export async function getMaterialLibraryInfo(): Promise<MaterialLibraryInfo> {
-  const { data } = await api.get('/admin/settings/material-library');
+  const { data } = await api.get<MaterialLibraryInfo>('/admin/settings/material-library');
   return data;
 }
 
diff --git a/frontend/src/api/uploads.ts b/frontend/src/api/uploads.ts
index ce4f390..b058806 100644
--- a/frontend/src/api/uploads.ts
+++ b/frontend/src/api/uploads.ts
@@ -93,10 +93,18 @@ export async function finalizeExcelImport(data: ExcelFinalizeRequest): Promise<O
   return res.data
 }
 
-export async function uploadStep(file: File) {
+export interface StepUploadResponse {
+  cad_file_id: string
+  original_name: string
+  file_hash: string
+  status: string
+  matched_items: string[]
+}
+
+export async function uploadStep(file: File): Promise<StepUploadResponse> {
   const form = new FormData()
   form.append('file', file)
-  const res = await api.post('/uploads/step', form, {
+  const res = await api.post<StepUploadResponse>('/uploads/step', form, {
     headers: { 'Content-Type': 'multipart/form-data' },
   })
   return res.data
diff --git a/frontend/src/api/worker.ts b/frontend/src/api/worker.ts
index ad085ad..1e48e47 100644
--- a/frontend/src/api/worker.ts
+++ b/frontend/src/api/worker.ts
@@ -94,7 +94,7 @@ export function renderLogStreamUrl(orderLineId: string): string {
 export interface QueueTask {
   task_id: string
   task_name: string
-  args: any[]
+  args: unknown[]
   argsrepr: string
   status: 'pending' | 'active' | 'reserved'
   worker?: string