diff --git a/db/repository.py b/db/repository.py
index 6edcbc1..57fdba6 100644
--- a/db/repository.py
+++ b/db/repository.py
@@ -70,16 +70,26 @@ class Repository:
             return [SourceChannel(**dict(r)) for r in rows]
 
     async def get_source_by_channel_id(self, channel_id: int) -> Optional[SourceChannel]:
+        if not isinstance(channel_id, int) or not (-9223372036854775808 <= channel_id <= 9223372036854775807):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM sources WHERE channel_id = $1;", channel_id)
-            return SourceChannel(**dict(row)) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM sources WHERE channel_id = $1;", channel_id)
+                return SourceChannel(**dict(row)) if row else None
+            except Exception:
+                return None
 
     async def get_source_by_id(self, source_id: int) -> Optional[SourceChannel]:
+        if not isinstance(source_id, int) or not (1 <= source_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM sources WHERE id = $1;", source_id)
-            return SourceChannel(**dict(row)) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM sources WHERE id = $1;", source_id)
+                return SourceChannel(**dict(row)) if row else None
+            except Exception:
+                return None
 
     async def update_source_context_count(self, source_id: int, count: int) -> None:
         pool = await self._get_pool()
@@ -133,10 +143,15 @@ class Repository:
             return [_parse_source_website_row(r) for r in rows]
 
     async def get_source_website_by_id(self, site_id: int) -> Optional[SourceWebsite]:
+        if not isinstance(site_id, int) or not (1 <= site_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM source_websites WHERE id = $1;", site_id)
-            return _parse_source_website_row(row) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM source_websites WHERE id = $1;", site_id)
+                return _parse_source_website_row(row) if row else None
+            except Exception:
+                return None
 
     async def get_source_websites_by_category(self, category_id: Optional[int]) -> List[SourceWebsite]:
         pool = await self._get_pool()
@@ -363,10 +378,15 @@ class Repository:
             return [TargetChannel(**dict(r)) for r in rows]
 
     async def get_target_by_id(self, target_id: int) -> Optional[TargetChannel]:
+        if not isinstance(target_id, int) or not (1 <= target_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM targets WHERE id = $1;", target_id)
-            return TargetChannel(**dict(row)) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM targets WHERE id = $1;", target_id)
+                return TargetChannel(**dict(row)) if row else None
+            except Exception:
+                return None
 
     async def set_target_auto_sources(self, target_id: int, source_channel_ids: List[int]) -> None:
         """Replace the set of source channels auto-routed into this target."""
@@ -459,10 +479,15 @@ class Repository:
                 return None
 
     async def get_post_by_id(self, post_id: int) -> Optional[Post]:
+        if not isinstance(post_id, int) or not (1 <= post_id <= 9223372036854775807):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM posts WHERE id = $1;", post_id)
-            return _parse_post_row(row) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM posts WHERE id = $1;", post_id)
+                return _parse_post_row(row) if row else None
+            except Exception:
+                return None
 
     async def get_recent_source_posts(
         self,
@@ -862,21 +887,26 @@ class Repository:
             return [AIProviderProfile(**dict(r)) for r in rows]
 
     async def get_provider_profile_by_id(self, profile_id: int) -> Optional[AIProviderProfile]:
+        if not isinstance(profile_id, int) or not (1 <= profile_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow(
-                """
-                SELECT p.id, p.name, p.provider_type, p.model, p.base_url, p.api_key, p.reasoning_effort, p.is_active,
-                       p.fallback_provider_id, p.supports_vision,
-                       fb.name as fallback_provider_name,
-                       to_char(p.created_at, 'YYYY-MM-DD HH24:MI:SS') as created_at
-                FROM ai_providers p
-                LEFT JOIN ai_providers fb ON p.fallback_provider_id = fb.id
-                WHERE p.id = $1;
-                """,
-                profile_id
-            )
-            return AIProviderProfile(**dict(row)) if row else None
+            try:
+                row = await conn.fetchrow(
+                    """
+                    SELECT p.id, p.name, p.provider_type, p.model, p.base_url, p.api_key, p.reasoning_effort, p.is_active,
+                           p.fallback_provider_id, p.supports_vision,
+                           fb.name as fallback_provider_name,
+                           to_char(p.created_at, 'YYYY-MM-DD HH24:MI:SS') as created_at
+                    FROM ai_providers p
+                    LEFT JOIN ai_providers fb ON p.fallback_provider_id = fb.id
+                    WHERE p.id = $1;
+                    """,
+                    profile_id
+                )
+                return AIProviderProfile(**dict(row)) if row else None
+            except Exception:
+                return None
 
     async def get_active_provider_profile(self) -> Optional[AIProviderProfile]:
         pool = await self._get_pool()
@@ -983,10 +1013,15 @@ class Repository:
             return [ChannelCategory(**dict(r)) for r in rows]
 
     async def get_category_by_id(self, cat_id: int) -> Optional[ChannelCategory]:
+        if not isinstance(cat_id, int) or not (1 <= cat_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM channel_categories WHERE id = $1;", cat_id)
-            return ChannelCategory(**dict(row)) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM channel_categories WHERE id = $1;", cat_id)
+                return ChannelCategory(**dict(row)) if row else None
+            except Exception:
+                return None
 
     async def update_category(self, cat_id: int, name: Optional[str] = None, description: Optional[str] = None, cat_type: Optional[str] = None) -> None:
         pool = await self._get_pool()
@@ -1092,16 +1127,26 @@ class Repository:
             return [_parse_admin_channel_row(r) for r in rows]
 
     async def get_admin_channel_by_id(self, admin_id: int) -> Optional[AdminReviewChannel]:
+        if not isinstance(admin_id, int) or not (1 <= admin_id <= 2147483647):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM admin_channels WHERE id = $1;", admin_id)
-            return _parse_admin_channel_row(row) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM admin_channels WHERE id = $1;", admin_id)
+                return _parse_admin_channel_row(row) if row else None
+            except Exception:
+                return None
 
     async def get_admin_channel_by_telegram_id(self, channel_id: int) -> Optional[AdminReviewChannel]:
+        if not isinstance(channel_id, int) or not (-9223372036854775808 <= channel_id <= 9223372036854775807):
+            return None
         pool = await self._get_pool()
         async with pool.acquire() as conn:
-            row = await conn.fetchrow("SELECT * FROM admin_channels WHERE channel_id = $1;", channel_id)
-            return _parse_admin_channel_row(row) if row else None
+            try:
+                row = await conn.fetchrow("SELECT * FROM admin_channels WHERE channel_id = $1;", channel_id)
+                return _parse_admin_channel_row(row) if row else None
+            except Exception:
+                return None
 
     async def get_default_admin_channel(self) -> Optional[AdminReviewChannel]:
         pool = await self._get_pool()
diff --git a/services/admin_bot.py b/services/admin_bot.py
index 7bb639b..b13cd1c 100644
--- a/services/admin_bot.py
+++ b/services/admin_bot.py
@@ -654,24 +654,31 @@ class AdminBotService:
 
         tag_line = f"🏷 <b>موضوع:</b> #{post.subject}\n\n" if getattr(post, "subject", None) else ""
 
-        if -999999999 <= post.source_channel_id <= -900000000:
-            site_id = abs(post.source_channel_id + 900000000)
-            site = await self.repo.get_source_website_by_id(site_id)
-            if site and site.name:
-                source_label = f"🌐 وبسایت <b>{site.name}</b>"
-            elif site and site.url:
-                source_label = f"🌐 وبسایت <b>{site.url}</b>"
+        source_label = "کانال"
+        try:
+            if post.source_channel_id is not None and -999999999 <= post.source_channel_id <= -900000000:
+                site_id = abs(post.source_channel_id + 900000000)
+                site = await self.repo.get_source_website_by_id(site_id)
+                if site and site.name:
+                    source_label = f"🌐 وبسایت <b>{site.name}</b>"
+                elif site and site.url:
+                    source_label = f"🌐 وبسایت <b>{site.url}</b>"
+                else:
+                    source_label = f"🌐 وبسایت <code>#{site_id}</code>"
+            elif post.source_channel_id is not None:
+                src = await self.repo.get_source_by_channel_id(post.source_channel_id)
+                if src and src.title:
+                    user_part = f" (@{src.username})" if src.username else ""
+                    source_label = f"📢 کانال <b>{src.title}</b>{user_part}"
+                elif src and src.username:
+                    source_label = f"📢 کانال @<b>{src.username}</b>"
+                else:
+                    source_label = f"کانال <code>{post.source_channel_id}</code>"
             else:
-                source_label = f"🌐 وبسایت <code>#{site_id}</code>"
-        else:
-            src = await self.repo.get_source_by_channel_id(post.source_channel_id)
-            if src and src.title:
-                user_part = f" (@{src.username})" if src.username else ""
-                source_label = f"📢 کانال <b>{src.title}</b>{user_part}"
-            elif src and src.username:
-                source_label = f"📢 کانال @<b>{src.username}</b>"
-            else:
-                source_label = f"کانال <code>{post.source_channel_id}</code>"
+                source_label = "کانال نامشخص"
+        except Exception as e:
+            logger.debug(f"Error formatting source label for post {post.id}: {e}")
+            source_label = f"شناسه <code>{post.source_channel_id}</code>"
 
         caption = (
             f"📥 <b>پست جدید از {source_label}:</b>\n\n"
@@ -685,19 +692,22 @@ class AdminBotService:
 
     async def get_effective_review_channel_id(self, post: Post) -> Optional[int]:
         """Determine which Admin Review Channel this post should be sent to."""
-        if -999999999 <= post.source_channel_id <= -900000000:
-            site_id = abs(post.source_channel_id + 900000000)
-            site = await self.repo.get_source_website_by_id(site_id)
-            if site and site.admin_channel_id:
-                return site.admin_channel_id
-        else:
-            src = await self.repo.get_source_by_channel_id(post.source_channel_id)
-            if src and src.admin_channel_id:
-                return src.admin_channel_id
+        try:
+            if post.source_channel_id is not None and -999999999 <= post.source_channel_id <= -900000000:
+                site_id = abs(post.source_channel_id + 900000000)
+                site = await self.repo.get_source_website_by_id(site_id)
+                if site and site.admin_channel_id:
+                    return site.admin_channel_id
+            elif post.source_channel_id is not None:
+                src = await self.repo.get_source_by_channel_id(post.source_channel_id)
+                if src and src.admin_channel_id:
+                    return src.admin_channel_id
 
-        default_adm = await self.repo.get_default_admin_channel()
-        if default_adm and default_adm.channel_id:
-            return default_adm.channel_id
+            default_adm = await self.repo.get_default_admin_channel()
+            if default_adm and default_adm.channel_id:
+                return default_adm.channel_id
+        except Exception as e:
+            logger.error(f"Error resolving review channel for post {post.id}: {e}")
 
         return self.review_channel_id or None
 
@@ -1707,30 +1717,38 @@ class AdminBotService:
 
     def _register_handlers(self):
         # --- Start / Menu ---
-        @self.client.on(events.NewMessage(pattern=r"(?i)^(/start|/menu|منو|منوی اصلی|🏠 منوی اصلی)$"))
+        @self.client.on(events.NewMessage(pattern=r"(?i)^(/start(@\w+)?|/srart(@\w+)?|/strt(@\w+)?|/starrt(@\w+)?|/menu(@\w+)?|شروع|منو|منوی اصلی|🏠 منوی اصلی)(\s.*)?$"))
         async def cmd_start(event: events.NewMessage.Event):
             if not self.is_admin(event.sender_id):
                 await event.reply(f"⛔ دسترسی غیرمجاز. شناسه عددی شما: <code>{event.sender_id}</code>", parse_mode="html")
                 return
 
-            self.user_states.pop(event.sender_id, None)
+            try:
+                self.user_states.pop(event.sender_id, None)
 
-            userbot_status = "🔴 قطع / نیاز به لاگین"
-            if self.collector and self.collector.client.is_connected() and await self.collector.client.is_user_authorized():
-                me = await self.collector.client.get_me()
-                userbot_status = f"🟢 آنلاین ({me.first_name})"
+                userbot_status = "🔴 قطع / نیاز به لاگین"
+                if self.collector and self.collector.client.is_connected() and await self.collector.client.is_user_authorized():
+                    me = await self.collector.client.get_me()
+                    userbot_status = f"🟢 آنلاین ({me.first_name})"
 
-            def_adm = await self.repo.get_default_admin_channel()
-            adm_label = f"<b>{def_adm.title}</b> (<code>{def_adm.channel_id}</code>)" if (def_adm and def_adm.title) else (f"<code>{self.review_channel_id}</code>" if self.review_channel_id else "تعریف‌نشده")
+                def_adm = await self.repo.get_default_admin_channel()
+                adm_label = f"<b>{def_adm.title}</b> (<code>{def_adm.channel_id}</code>)" if (def_adm and def_adm.title) else (f"<code>{self.review_channel_id}</code>" if self.review_channel_id else "تعریف‌نشده")
 
-            welcome_text = (
-                "👋 <b>به پنل مدیریت سیستم هوشمند کپی‌کار خوش آمدید!</b>\n\n"
-                f"• 🤖 <b>وضعیت ربات جمع‌آوری‌کننده:</b> {userbot_status}\n"
-                f"• 📋 <b>کانال نظارت ادمین:</b> {adm_label}\n\n"
-                "برای مدیریت کانال‌ها از دکمه‌های زیر استفاده کنید:"
-            )
-            menu = await self.get_menu()
-            await event.reply(welcome_text, parse_mode="html", buttons=menu)
+                welcome_text = (
+                    "👋 <b>به پنل مدیریت سیستم هوشمند کپی‌کار خوش آمدید!</b>\n\n"
+                    f"• 🤖 <b>وضعیت ربات جمع‌آوری‌کننده:</b> {userbot_status}\n"
+                    f"• 📋 <b>کانال نظارت ادمین:</b> {adm_label}\n\n"
+                    "برای مدیریت کانال‌ها از دکمه‌های زیر استفاده کنید:"
+                )
+                menu = await self.get_menu()
+                await event.reply(welcome_text, parse_mode="html", buttons=menu)
+            except Exception as e:
+                logger.error(f"Error executing cmd_start: {e}", exc_info=True)
+                try:
+                    menu = await self.get_menu()
+                    await event.reply("👋 <b>به پنل مدیریت سیستم هوشمند کپی‌کار خوش آمدید!</b>", parse_mode="html", buttons=menu)
+                except Exception:
+                    pass
 
         # --- 5 Primary Category Hubs: Copy, AI, Bots, System, Monitor ---
         @self.client.on(events.NewMessage(pattern=r"(?i)^(/copy|📋.*|.*copy.*|.*محتوا.*)$"))
@@ -2032,25 +2050,31 @@ class AdminBotService:
             return
 
         text = (event.raw_text or "").strip()
+        first_word = text.split()[0].lower() if text else ""
 
-        # Ignore main menu commands
-        if text in ["/start", "/menu", "منو", "منوی اصلی", "🏠 منوی اصلی",
-                    "/copy", "📋 مدیریت محتوا (Copy)", "📋 مدیریت محتوا", "📋 copy (محتوا)", "📋 Copy (محتوا)", "📋 کپی", "Copy",
-                    "/ai", "🧠 هوش مصنوعی (AI)", "🧠 هوش مصنوعی", "🧠 ai (هوش مصنوعی)", "🧠 AI (هوش مصنوعی)", "🧠 تنظیمات AI", "🧠 تنظیمات و لاگ‌های AI", "AI",
-                    "/bots", "🤖 کانال‌ها و وب (Bots)", "🤖 کانال‌ها و وب", "🤖 bots (کانال‌ها و ربات‌ها)", "🤖 Bots (کانال‌ها و ربات‌ها)", "🤖 کانال‌ها و ربات‌ها", "Bots",
-                    "/system", "⚙️ مدیریت سیستم (System)", "⚙️ مدیریت سیستم", "⚙️ system (سیستم)", "⚙️ System (سیستم)", "System",
-                    "/monitor", "📊 مانیتورینگ (Monitor)", "📊 مانیتورینگ", "📊 monitor (مانیتورینگ)", "📊 Monitor (مانیتورینگ)", "Monitor",
-                    "/stats", "/report", "📊 آمار ناوگان", "📊 آمار و وضعیت ناوگان", "📊 گزارش و آمار سیستم",
-                    "/sources", "📡 کانال‌های مبدا", "/targets", "🎯 کانال‌های مقصد",
-                    "/websites", "/sites", "🌐 وبسایت‌های مبدا",
-                    "/request_code", "🔑 کد لاگین", "🔑 درخواست کد لاگین",
-                    "/pending", "📨 پست‌های بررسی‌نشده", "📨 ارسال پست‌های بررسی‌نشده",
-                    "/errors", "/err", "⚠️ خطاهای سیستم",
-                    "/categories", "/cats", "📂 دسته‌بندی‌ها", "📂 دسته‌بندی کانال‌ها",
-                    "/add", "➕ افزودن مبدا / مقصد", "➕ افزودن کانال مبدا", "➕ افزودن کانال مقصد",
-                    "/pause", "/stop", "🛑 توقف سیستم", "🛑 توقف اضطراری سیستم",
-                    "/resume", "/start_fleet", "▶️ راه‌اندازی سیستم", "▶️ راه‌اندازی و ادامه سیستم",
-                    "/help", "❓ راهنمای سیستم"]:
+        # Ignore main menu commands and start variants
+        if (
+            re.match(r"(?i)^(/start(@\w+)?|/srart(@\w+)?|/strt(@\w+)?|/starrt(@\w+)?|/menu(@\w+)?|شروع|منو|منوی اصلی|🏠 منوی اصلی)$", first_word)
+            or text in [
+                "/start", "/menu", "منو", "منوی اصلی", "🏠 منوی اصلی", "شروع",
+                "/copy", "📋 مدیریت محتوا (Copy)", "📋 مدیریت محتوا", "📋 copy (محتوا)", "📋 Copy (محتوا)", "📋 کپی", "Copy",
+                "/ai", "🧠 هوش مصنوعی (AI)", "🧠 هوش مصنوعی", "🧠 ai (هوش مصنوعی)", "🧠 AI (هوش مصنوعی)", "🧠 تنظیمات AI", "🧠 تنظیمات و لاگ‌های AI", "AI",
+                "/bots", "🤖 کانال‌ها و وب (Bots)", "🤖 کانال‌ها و وب", "🤖 bots (کانال‌ها و ربات‌ها)", "🤖 Bots (کانال‌ها و ربات‌ها)", "🤖 کانال‌ها و ربات‌ها", "Bots",
+                "/system", "⚙️ مدیریت سیستم (System)", "⚙️ مدیریت سیستم", "⚙️ تنظیمات و سیستم", "⚙️ system (سیستم)", "⚙️ System (سیستم)", "System",
+                "/monitor", "📊 مانیتورینگ (Monitor)", "📊 مانیتورینگ", "📊 monitor (مانیتورینگ)", "📊 Monitor (مانیتورینگ)", "Monitor",
+                "/stats", "/report", "📊 آمار ناوگان", "📊 آمار و وضعیت ناوگان", "📊 گزارش و آمار سیستم",
+                "/sources", "📡 کانال‌های مبدا", "📡 مبداها", "/targets", "🎯 کانال‌های مقصد", "🎯 مقصدها",
+                "/websites", "/sites", "🌐 وبسایت‌های مبدا", "🌐 وبسایت‌ها",
+                "/request_code", "🔑 کد لاگین", "🔑 درخواست کد لاگین", "🔑 لاگین یوزربات",
+                "/pending", "📨 پست‌های بررسی‌نشده", "📨 ارسال پست‌های بررسی‌نشده", "📨 بررسی‌نشده",
+                "/errors", "/err", "⚠️ خطاهای سیستم",
+                "/categories", "/cats", "📂 دسته‌بندی‌ها", "📂 دسته‌بندی کانال‌ها",
+                "/add", "➕ افزودن مبدا / مقصد", "➕ افزودن کانال مبدا", "➕ افزودن کانال مقصد", "➕ افزودن مبدا", "➕ افزودن مقصد", "➕ افزودن وبسایت",
+                "/pause", "/stop", "🛑 توقف سیستم", "🛑 توقف اضطراری سیستم",
+                "/resume", "/start_fleet", "▶️ راه‌اندازی سیستم", "▶️ راه‌اندازی و ادامه سیستم",
+                "/help", "❓ راهنمای سیستم", "❓ راهنما"
+            ]
+        ):
             return
 
         # Cancel command
diff --git a/tests/test_start_command_resilience.py b/tests/test_start_command_resilience.py
new file mode 100644
index 0000000..c43d08b
--- /dev/null
+++ b/tests/test_start_command_resilience.py
@@ -0,0 +1,68 @@
+import re
+import pytest
+from unittest.mock import AsyncMock, MagicMock
+from db.repository import Repository
+from db.models import Post, SourceWebsite, SourceChannel
+from services.admin_bot import AdminBotService
+
+def test_start_command_regex():
+    pattern = r"(?i)^(/start(@\w+)?|/srart(@\w+)?|/strt(@\w+)?|/starrt(@\w+)?|/menu(@\w+)?|شروع|منو|منوی اصلی|🏠 منوی اصلی)(\s.*)?$"
+    
+    valid_inputs = [
+        "/start",
+        "/START",
+        "/start@copykar_2026_bot",
+        "/start  ",
+        "/srart",
+        "/srart@copykar_2026_bot",
+        "/strt",
+        "/starrt",
+        "/menu",
+        "/menu@copykar_2026_bot",
+        "منو",
+        "منوی اصلی",
+        "🏠 منوی اصلی",
+        "شروع",
+        "/start something",
+    ]
+    for inp in valid_inputs:
+        assert re.match(pattern, inp), f"Failed to match: {inp}"
+
+    invalid_inputs = [
+        "/start123",
+        "سلام",
+        "/settings",
+        "test",
+    ]
+    for inp in invalid_inputs:
+        assert not re.match(pattern, inp), f"Should not match: {inp}"
+
+@pytest.mark.asyncio
+async def test_repository_safe_bounds_without_db():
+    repo = Repository()
+    # Out of range integer bounds should return None without error
+    assert await repo.get_source_website_by_id(-1) is None
+    assert await repo.get_source_website_by_id(0) is None
+    assert await repo.get_source_website_by_id(99999999999999) is None
+    assert await repo.get_source_by_id(-5) is None
+    assert await repo.get_target_by_id(-10) is None
+    assert await repo.get_category_by_id(-1) is None
+    assert await repo.get_admin_channel_by_id(0) is None
+
+@pytest.mark.asyncio
+async def test_admin_bot_safe_caption_formatting():
+    repo = MagicMock()
+    repo.get_source_website_by_id = AsyncMock(side_effect=Exception("Database connection down"))
+    repo.get_source_by_channel_id = AsyncMock(side_effect=Exception("Database connection down"))
+    bot = AdminBotService(repo=repo)
+
+    post = Post(
+        id=1,
+        source_channel_id=-900000001,
+        source_message_id=10,
+        raw_text="متن تستی",
+        status="raw"
+    )
+    caption = await bot._format_raw_post_caption(post)
+    assert "متن تستی" in caption
+    assert "شناسه <code>-900000001</code>" in caption