diff --git a/docker-compose.yml b/docker-compose.yml
index dd81221..d4c89df 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -290,6 +290,7 @@ services:
       POCKETBASE_ADMIN_EMAIL: "${POCKETBASE_ADMIN_EMAIL}"
       POCKETBASE_ADMIN_PASSWORD: "${POCKETBASE_ADMIN_PASSWORD}"
       AUTH_SECRET: "${AUTH_SECRET}"
+      DEBUG_LOGIN_TOKEN: "${DEBUG_LOGIN_TOKEN}"
       PUBLIC_MINIO_PUBLIC_URL: "${MINIO_PUBLIC_ENDPOINT}"
       # Valkey
       VALKEY_ADDR: "valkey:6379"
diff --git a/ui/src/routes/api/auth/debug-login/+server.ts b/ui/src/routes/api/auth/debug-login/+server.ts
new file mode 100644
index 0000000..e332402
--- /dev/null
+++ b/ui/src/routes/api/auth/debug-login/+server.ts
@@ -0,0 +1,73 @@
+import { redirect, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { getUserByUsername, createUserSession } from '$lib/server/pocketbase';
+import { createAuthToken } from '../../../../hooks.server';
+import { env } from '$env/dynamic/private';
+import { log } from '$lib/server/logger';
+import { randomBytes } from 'node:crypto';
+
+const AUTH_COOKIE = 'libnovel_auth';
+const ONE_YEAR = 60 * 60 * 24 * 365;
+
+/**
+ * GET /api/auth/debug-login?token=<DEBUG_LOGIN_TOKEN>&username=<username>
+ *
+ * One-shot debug bypass: verifies a shared secret token, then mints a real
+ * auth cookie for the given user (defaults to the first admin account) and
+ * redirects to /.
+ *
+ * Requires DEBUG_LOGIN_TOKEN env var to be set. Disabled (404) when the var
+ * is absent or empty.
+ */
+export const GET: RequestHandler = async ({ url, cookies, request }) => {
+	const debugToken = env.DEBUG_LOGIN_TOKEN ?? '';
+	if (!debugToken) {
+		error(404, 'Not found');
+	}
+
+	const provided = url.searchParams.get('token') ?? '';
+	// Constant-time comparison to prevent timing attacks
+	if (provided.length !== debugToken.length) {
+		log.warn('api/auth/debug-login', 'bad token attempt');
+		error(401, 'Invalid token');
+	}
+	let diff = 0;
+	for (let i = 0; i < debugToken.length; i++) {
+		diff |= provided.charCodeAt(i) ^ debugToken.charCodeAt(i);
+	}
+	if (diff !== 0) {
+		log.warn('api/auth/debug-login', 'bad token attempt');
+		error(401, 'Invalid token');
+	}
+
+	const username = url.searchParams.get('username') ?? 'kamil_alekber_2e99';
+	const user = await getUserByUsername(username);
+	if (!user) {
+		error(404, `User '${username}' not found`);
+	}
+
+	const authSessionId = randomBytes(16).toString('hex');
+	const userAgent = request.headers.get('user-agent') ?? '';
+	const ip =
+		request.headers.get('x-forwarded-for')?.split(',')[0]?.trim() ??
+		request.headers.get('x-real-ip') ??
+		'debug';
+
+	createUserSession(user.id, authSessionId, userAgent, ip).catch((e) =>
+		log.warn('api/auth/debug-login', 'createUserSession failed (non-fatal)', { err: String(e) })
+	);
+
+	const token = createAuthToken(user.id, user.username, user.role ?? 'user', authSessionId);
+
+	cookies.set(AUTH_COOKIE, token, {
+		path: '/',
+		httpOnly: true,
+		sameSite: 'lax',
+		maxAge: ONE_YEAR
+	});
+
+	log.info('api/auth/debug-login', 'debug login used', { username: user.username, ip });
+
+	const next = url.searchParams.get('next') ?? '/';
+	redirect(302, next);
+};