feat(telegram): add config option to disable link previews

gateway/platforms/telegram.py

@@ -18,6 +18,10 @@ logger = logging.getLogger(__name__)
 
 try:
     from telegram import Update, Bot, Message, InlineKeyboardButton, InlineKeyboardMarkup
+    try:
+        from telegram import LinkPreviewOptions
+    except ImportError:
+        LinkPreviewOptions = None
     from telegram.ext import (
         Application,
         CommandHandler,
@@ -36,6 +40,7 @@ except ImportError:
     Message = Any
     InlineKeyboardButton = Any
     InlineKeyboardMarkup = Any
+    LinkPreviewOptions = None
     Application = Any
     CommandHandler = Any
     CallbackQueryHandler = Any
@@ -137,6 +142,7 @@ class TelegramAdapter(BasePlatformAdapter):
         self._webhook_mode: bool = False
         self._mention_patterns = self._compile_mention_patterns()
         self._reply_to_mode: str = getattr(config, 'reply_to_mode', 'first') or 'first'
+        self._disable_link_previews: bool = self._coerce_bool_extra("disable_link_previews", False)
         # Buffer rapid/album photo updates so Telegram image bursts are handled
         # as a single MessageEvent instead of self-interrupting multiple turns.
         self._media_batch_delay_seconds = float(os.getenv("HERMES_TELEGRAM_MEDIA_BATCH_DELAY_SECONDS", "0.8"))
@@ -202,6 +208,26 @@ class TelegramAdapter(BasePlatformAdapter):
             pass
         return isinstance(error, OSError)
 
+    def _coerce_bool_extra(self, key: str, default: bool = False) -> bool:
+        value = self.config.extra.get(key) if getattr(self.config, "extra", None) else None
+        if value is None:
+            return default
+        if isinstance(value, str):
+            lowered = value.strip().lower()
+            if lowered in ("true", "1", "yes", "on"):
+                return True
+            if lowered in ("false", "0", "no", "off"):
+                return False
+            return default
+        return bool(value)
+
+    def _link_preview_kwargs(self) -> Dict[str, Any]:
+        if not self._disable_link_previews:
+            return {}
+        if LinkPreviewOptions is not None:
+            return {"link_preview_options": LinkPreviewOptions(is_disabled=True)}
+        return {"disable_web_page_preview": True}
+
     async def _handle_polling_network_error(self, error: Exception) -> None:
         """Reconnect polling after a transient network interruption.
 
@@ -856,6 +882,7 @@ class TelegramAdapter(BasePlatformAdapter):
                                 parse_mode=ParseMode.MARKDOWN_V2,
                                 reply_to_message_id=reply_to_id,
                                 message_thread_id=effective_thread_id,
+                                **self._link_preview_kwargs(),
                             )
                         except Exception as md_error:
                             # Markdown parsing failed, try plain text
@@ -868,6 +895,7 @@ class TelegramAdapter(BasePlatformAdapter):
                                     parse_mode=None,
                                     reply_to_message_id=reply_to_id,
                                     message_thread_id=effective_thread_id,
+                                    **self._link_preview_kwargs(),
                                 )
                             else:
                                 raise
@@ -1055,6 +1083,7 @@ class TelegramAdapter(BasePlatformAdapter):
                 text=text,
                 parse_mode=ParseMode.MARKDOWN,
                 reply_markup=keyboard,
+                **self._link_preview_kwargs(),
             )
             return SendResult(success=True, message_id=str(msg.message_id))
         except Exception as e:
@@ -1114,6 +1143,7 @@ class TelegramAdapter(BasePlatformAdapter):
                 "text": text,
                 "parse_mode": ParseMode.MARKDOWN,
                 "reply_markup": keyboard,
+                **self._link_preview_kwargs(),
             }
             if thread_id:
                 kwargs["message_thread_id"] = int(thread_id)
@@ -1184,6 +1214,7 @@ class TelegramAdapter(BasePlatformAdapter):
                 parse_mode=ParseMode.MARKDOWN,
                 reply_markup=keyboard,
                 message_thread_id=int(thread_id) if thread_id else None,
+                **self._link_preview_kwargs(),
             )
 
             # Store picker state keyed by chat_id

tests/gateway/test_telegram_approval_buttons.py

@@ -50,9 +50,9 @@ from gateway.platforms.telegram import TelegramAdapter
 from gateway.config import Platform, PlatformConfig
 
 
-def _make_adapter():
+def _make_adapter(extra=None):
     """Create a TelegramAdapter with mocked internals."""
-    config = PlatformConfig(enabled=True, token="test-token")
+    config = PlatformConfig(enabled=True, token="test-token", extra=extra or {})
     adapter = TelegramAdapter(config)
     adapter._bot = AsyncMock()
     adapter._app = MagicMock()
@@ -134,6 +134,23 @@ class TestTelegramExecApproval:
         )
         assert result.success is False
 
+    @pytest.mark.asyncio
+    async def test_disable_link_previews_sets_preview_kwargs(self):
+        adapter = _make_adapter(extra={"disable_link_previews": True})
+        mock_msg = MagicMock()
+        mock_msg.message_id = 42
+        adapter._bot.send_message = AsyncMock(return_value=mock_msg)
+
+        await adapter.send_exec_approval(
+            chat_id="12345", command="ls", session_key="s"
+        )
+
+        kwargs = adapter._bot.send_message.call_args[1]
+        assert (
+            kwargs.get("disable_web_page_preview") is True
+            or kwargs.get("link_preview_options") is not None
+        )
+
     @pytest.mark.asyncio
     async def test_truncates_long_command(self):
         adapter = _make_adapter()