diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d8167c..fa22455 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Fixed
+- Fixed TypeScript build error in `frontend/src/app/accounts/page.tsx`: replaced non-existent `account.username` with `account.email_address`, `account.last_checked_at` with `account.last_check_at`, and `account.last_error` with `account.last_error_message` (the backend intentionally excludes `username` from API responses for security)
+- Fixed TypeScript error in `frontend/src/app/auth/callback/page.tsx`: `TokenResponse` doesn't include `user`; now fetches user via `userApi.getCurrentUser()` after OAuth token exchange
+- Fixed TypeScript errors in `frontend/src/app/dashboard/page.tsx`: replaced non-existent `errors_count` with `emails_failed` on `ProcessingRun`
+- Fixed TypeScript errors in `frontend/src/components/AddMailAccountModal.tsx`: removed invalid `account.username` access, added missing required fields to initial form state, and fixed autoDetect suggestions access
+- Made `email_address`, `use_tls`, `forward_to` optional in the `MailAccountCreate` TypeScript interface to align with form usage
+- Added typed suggestion fields to `autoDetect` return type in `api.ts`
+- Excluded test files (`*.test.ts`, `*.spec.ts`) from TypeScript compilation in `tsconfig.json`
 - Upgraded Node.js base image in `frontend/Dockerfile` from `node:18-alpine` to `node:20-alpine` to satisfy the Node.js >= 20.9.0 requirement for Next.js and fix Docker build failures
 - Removed `actions/attest-build-provenance` step and associated `id-token: write` / `attestations: write` permissions from the CI `build` job — this action is not available for private user-owned repositories and caused every build to fail
 - Downgraded `eslint` from `^10` to `^9` in the frontend to resolve `TypeError: contextOrFilename.getFilename is not a function` caused by ESLint 10 removing the `getFilename()` API used by `eslint-plugin-react` bundled in `eslint-config-next`
diff --git a/frontend/src/app/accounts/page.tsx b/frontend/src/app/accounts/page.tsx
index 95dda97..0a69fe8 100644
--- a/frontend/src/app/accounts/page.tsx
+++ b/frontend/src/app/accounts/page.tsx
@@ -77,7 +77,7 @@ export default function AccountsPage() {
                         <h3 className="text-lg font-semibold text-gray-900 mb-1">
                           {account.name}
                         </h3>
-                        <p className="text-sm text-gray-500">{account.username}</p>
+                        <p className="text-sm text-gray-500">{account.email_address}</p>
                       </div>
                       <div className="flex items-center gap-2">
                         {account.is_enabled ? (
@@ -113,17 +113,17 @@ export default function AccountsPage() {
                       </div>
                     </div>
 
-                    {account.last_checked_at && (
+                    {account.last_check_at && (
                       <div className="mb-4 text-xs text-gray-500">
-                        Last checked: {new Date(account.last_checked_at).toLocaleString()}
+                        Last checked: {new Date(account.last_check_at).toLocaleString()}
                       </div>
                     )}
 
-                    {account.last_error && (
+                    {account.last_error_message && (
                       <div className="mb-4 p-3 bg-red-50 border border-red-200 rounded-md">
                         <div className="flex items-start">
                           <AlertTriangle className="h-4 w-4 text-red-500 mr-2 mt-0.5 flex-shrink-0" />
-                          <p className="text-xs text-red-700">{account.last_error}</p>
+                          <p className="text-xs text-red-700">{account.last_error_message}</p>
                         </div>
                       </div>
                     )}
diff --git a/frontend/src/app/auth/callback/page.tsx b/frontend/src/app/auth/callback/page.tsx
index 165fb70..59aeb3c 100644
--- a/frontend/src/app/auth/callback/page.tsx
+++ b/frontend/src/app/auth/callback/page.tsx
@@ -2,7 +2,7 @@
 
 import { useEffect, useState } from 'react';
 import { useRouter, useSearchParams } from 'next/navigation';
-import { authApi } from '@/lib/api';
+import { authApi, userApi } from '@/lib/api';
 import { useAuthStore } from '@/store/authStore';
 import { Loader2, CheckCircle, XCircle } from 'lucide-react';
 
@@ -37,8 +37,9 @@ export default function AuthCallbackPage() {
         const response = await authApi.googleAuth(code, redirectUri);
         
         localStorage.setItem('access_token', response.access_token);
-        localStorage.setItem('user', JSON.stringify(response.user));
-        setUser(response.user);
+        const user = response.user ? response.user : await userApi.getCurrentUser();
+        localStorage.setItem('user', JSON.stringify(user));
+        setUser(user);
         
         setStatus('success');
         setMessage('Authentication successful! Redirecting...');
diff --git a/frontend/src/app/dashboard/page.tsx b/frontend/src/app/dashboard/page.tsx
index 8eb9b11..31036c0 100644
--- a/frontend/src/app/dashboard/page.tsx
+++ b/frontend/src/app/dashboard/page.tsx
@@ -63,7 +63,7 @@ export default function DashboardPage() {
         return new Date(r.started_at).toDateString() === today;
       })
       .reduce((sum, r) => sum + r.emails_forwarded, 0) || 0,
-    errors: runs?.filter((r) => r.errors_count > 0).length || 0,
+    errors: runs?.filter((r) => r.emails_failed > 0).length || 0,
   };
 
   return (
@@ -166,8 +166,8 @@ export default function DashboardPage() {
                             {run.emails_forwarded}
                           </td>
                           <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-500">
-                            {run.errors_count > 0 ? (
-                              <span className="text-red-600 font-medium">{run.errors_count}</span>
+                            {run.emails_failed > 0 ? (
+                              <span className="text-red-600 font-medium">{run.emails_failed}</span>
                             ) : (
                               <span className="text-gray-400">0</span>
                             )}
diff --git a/frontend/src/components/AddMailAccountModal.tsx b/frontend/src/components/AddMailAccountModal.tsx
index cea66d4..d73054f 100644
--- a/frontend/src/components/AddMailAccountModal.tsx
+++ b/frontend/src/components/AddMailAccountModal.tsx
@@ -25,7 +25,7 @@ export function AddMailAccountModal({ account, onClose }: AddMailAccountModalPro
     protocol: account?.protocol || 'pop3',
     host: account?.host || '',
     port: account?.port || 995,
-    username: account?.username || '',
+    username: '',
     password: '',
     use_ssl: account?.use_ssl ?? true,
     check_interval_minutes: account?.check_interval_minutes || 5,
@@ -70,14 +70,17 @@ export function AddMailAccountModal({ account, onClose }: AddMailAccountModalPro
 
     setAutoDetecting(true);
     try {
-      const settings = await mailAccountsApi.autoDetect(formData.username);
-      setFormData((prev) => ({
-        ...prev,
-        protocol: settings.protocol || prev.protocol,
-        host: settings.host || prev.host,
-        port: settings.port || prev.port,
-        use_ssl: settings.use_ssl ?? prev.use_ssl,
-      }));
+      const result = await mailAccountsApi.autoDetect(formData.username);
+      const suggestion = result.success && result.suggestions.length > 0 ? result.suggestions[0] : null;
+      if (suggestion) {
+        setFormData((prev) => ({
+          ...prev,
+          protocol: suggestion.protocol || prev.protocol,
+          host: suggestion.host || prev.host,
+          port: suggestion.port || prev.port,
+          use_ssl: suggestion.use_ssl ?? prev.use_ssl,
+        }));
+      }
       alert('Settings auto-detected successfully!');
     } catch {
       alert('Failed to auto-detect settings. Please enter manually.');
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index 41f5d8e..d115988 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -82,15 +82,15 @@ export interface MailAccount {
 
 export interface MailAccountCreate {
   name: string;
-  email_address: string;
+  email_address?: string;
   protocol: string;
   host: string;
   port: number;
   use_ssl: boolean;
-  use_tls: boolean;
+  use_tls?: boolean;
   username: string;
   password: string;
-  forward_to: string;
+  forward_to?: string;
   delivery_method?: string;
   is_enabled?: boolean;
   check_interval_minutes?: number;
@@ -111,10 +111,19 @@ export interface ProcessingRun {
   error_message?: string | null;
 }
 
+export interface AutoDetectSuggestion {
+  protocol?: string;
+  host?: string;
+  port?: number;
+  use_ssl?: boolean;
+  [key: string]: unknown;
+}
+
 interface TokenResponse {
   access_token: string;
   refresh_token: string;
   token_type: string;
+  user?: User;
 }
 
 // ── Auth API ────────────────────────────────────────────────────────────
@@ -215,10 +224,10 @@ export const mailAccountsApi = {
 
   async autoDetect(
     emailAddress: string
-  ): Promise<{ success: boolean; suggestions: Record<string, unknown>[] }> {
+  ): Promise<{ success: boolean; suggestions: AutoDetectSuggestion[] }> {
     const response = await api.post<{
       success: boolean;
-      suggestions: Record<string, unknown>[];
+      suggestions: AutoDetectSuggestion[];
     }>("/mail-accounts/auto-detect", { email_address: emailAddress });
     return response.data;
   },
diff --git a/frontend/tsconfig.json b/frontend/tsconfig.json
index cf9c65d..39993f0 100644
--- a/frontend/tsconfig.json
+++ b/frontend/tsconfig.json
@@ -30,5 +30,5 @@
     ".next/dev/types/**/*.ts",
     "**/*.mts"
   ],
-  "exclude": ["node_modules"]
+  "exclude": ["node_modules", "**/*.test.ts", "**/*.test.tsx", "**/*.spec.ts", "**/*.spec.tsx"]
 }