fix: add rich_messages config to disable sendRichMessage for Telegram Web (#4488)

nanobot/channels/telegram.py

@@ -351,6 +351,9 @@ class TelegramConfig(Base):
     streaming: bool = True
     # Enable inline keyboard buttons in Telegram messages.
     inline_keyboards: bool = False
+    # Use Bot API 10.1 sendRichMessage for markdown rendering.
+    # Disable if Telegram Web shows "message not supported" errors.
+    rich_messages: bool = True
     stream_edit_interval: float = Field(default=_STREAM_EDIT_INTERVAL_DEFAULT, ge=0.1)
     webhook_url: str = ""
     webhook_listen_host: str = "127.0.0.1"
@@ -803,6 +806,7 @@ class TelegramChannel(BaseChannel):
             # latches off permanently if the server doesn't support it.
             if (
                 not render_as_blockquote
+                and self.config.rich_messages
                 and not getattr(self, "_rich_send_disabled", False)
             ):
                 rich_ok = await self._try_send_rich(
@@ -911,7 +915,7 @@ class TelegramChannel(BaseChannel):
             # Skip when a streaming preview already exists to avoid the
             # delete-and-resend pattern that causes flickering and drops
             # line breaks (issue #4470).
-            if not buf.message_id and not getattr(self, "_rich_send_disabled", False):
+            if not buf.message_id and self.config.rich_messages and not getattr(self, "_rich_send_disabled", False):
                 reply_params = None
                 if reply_to_message_id := meta.get("message_id"):
                     reply_params = {"message_id": int(reply_to_message_id), "allow_sending_without_reply": True}

tests/channels/test_telegram_channel.py

@@ -505,6 +505,23 @@ async def test_send_rich_bad_request_does_not_latch_capability() -> None:
     assert len(channel._app.bot.sent_messages) == 1
 
 
+@pytest.mark.asyncio
+async def test_rich_messages_config_disabled_skips_sendRichMessage() -> None:
+    """When rich_messages=False, sendRichMessage should not be called."""
+    channel = TelegramChannel(
+        TelegramConfig(enabled=True, token="123:abc", allow_from=["*"], rich_messages=False),
+        MessageBus(),
+    )
+    channel._app = _FakeApp(lambda: None)
+    channel._app.bot.do_api_request = AsyncMock()
+
+    await channel.send(OutboundMessage(channel="telegram", chat_id="123", content="**hello**"))
+
+    channel._app.bot.do_api_request.assert_not_called()
+    assert len(channel._app.bot.sent_messages) == 1
+    assert channel._app.bot.sent_messages[0]["text"]
+
+
 @pytest.mark.asyncio
 async def test_on_error_logs_network_issues_as_warning(monkeypatch) -> None:
     from telegram.error import NetworkError