feat(telegram): opt-in Online/Offline bot status indicator (#49134)

Sets the Telegram bot's short description (the line under its name) to
"Online" on gateway connect and "Offline" on clean disconnect, gated
behind extra.status_indicator (off by default).

Telegram bots have no presence/online dot — that's a user-account
feature the Bot API doesn't expose for bots. The short description is
the closest available surface, so this gives users a way to tell whether
the gateway is up from the bot's profile.

- New extra.status_indicator flag (+ status_online/status_offline text
  overrides), read in __init__ via config.extra — no config-schema change.
- _set_status_indicator() helper: best-effort, swallows API errors so it
  never blocks connect/disconnect; truncates to Telegram's 120-char cap.
- Wired Online after _mark_connected(), Offline at top of disconnect()
  while the bot HTTP client is still alive.
- 9 unit tests + Telegram docs section.

Requested by @ilTrumpista, cc @Teknium.

gateway/platforms/telegram.py

@@ -476,6 +476,23 @@ class TelegramAdapter(BasePlatformAdapter):
         self._forum_command_registered: set[int] = set()
         # Lock per la registrazione sicura dei comandi nei forum supergroup
         self._forum_lock = asyncio.Lock()
+        # Status indicator: when enabled, the bot's short description (the line
+        # shown under its name in the profile) is set to "Online" on connect and
+        # "Offline" on clean disconnect, so users can tell whether the gateway is
+        # up. Telegram bots have no real presence/online dot (that's a user-account
+        # feature), so the short description is the closest available surface.
+        # Off by default — this mutates the bot's GLOBAL profile, visible to all
+        # users. Opt in via gateway config: extra.status_indicator: true, or set
+        # custom strings via extra.status_online / extra.status_offline.
+        self._status_indicator_enabled: bool = bool(
+            self.config.extra.get("status_indicator", False)
+        )
+        self._status_online_text: str = str(
+            self.config.extra.get("status_online", "Online")
+        )
+        self._status_offline_text: str = str(
+            self.config.extra.get("status_offline", "Offline")
+        )
         # DM Topics config from extra.dm_topics
         self._dm_topics_config: List[Dict[str, Any]] = self.config.extra.get("dm_topics", [])
         # Precomputed chat_ids that have DM topics configured (for O(1) root-DM ignore check)
@@ -2245,6 +2262,13 @@ class TelegramAdapter(BasePlatformAdapter):
             mode = "webhook" if self._webhook_mode else "polling"
             logger.info("[%s] Connected to Telegram (%s mode)", self.name, mode)
 
+            # Surface the gateway as "Online" in the bot's short description
+            # (opt-in via extra.status_indicator). Non-fatal.
+            try:
+                await self._set_status_indicator(online=True)
+            except Exception:
+                pass
+
             # Set up DM topics (Bot API 9.4 — Private Chat Topics)
             # Runs after connection is established so the bot can call createForumTopic.
             # Failures here are non-fatal — the bot works fine without topics.
@@ -2265,8 +2289,47 @@ class TelegramAdapter(BasePlatformAdapter):
             logger.error("[%s] Failed to connect to Telegram: %s", self.name, e, exc_info=True)
             return False
 
+    async def _set_status_indicator(self, online: bool) -> None:
+        """Set the bot's short description to the online/offline status text.
+
+        The short description is the line shown under the bot's name in its
+        profile. It is the closest Bot API surface to a presence indicator —
+        bots have no real online/offline dot (that's a user-account feature).
+
+        No-op unless ``extra.status_indicator`` is enabled. Best-effort: any
+        failure is logged at debug and swallowed so it never blocks connect or
+        disconnect. The default (no language_code) description applies to every
+        user who doesn't have a language-specific one set.
+        """
+        if not getattr(self, "_status_indicator_enabled", False):
+            return
+        bot = self._bot
+        if bot is None:
+            return
+        text = self._status_online_text if online else self._status_offline_text
+        # Telegram caps short_description at 120 chars.
+        text = text[:120]
+        try:
+            await bot.set_my_short_description(short_description=text)
+            logger.info("[%s] Set bot status indicator to %r", self.name, text)
+        except Exception as e:
+            logger.debug(
+                "[%s] Failed to set bot status indicator to %r: %s",
+                self.name, text, e,
+            )
+
     async def disconnect(self) -> None:
         """Stop polling/webhook, cancel pending album flushes, and disconnect."""
+        # Mark the bot "Offline" in its short description while the bot's HTTP
+        # client is still alive (before app shutdown closes it). Opt-in via
+        # extra.status_indicator. Non-fatal. This is the clean-shutdown path;
+        # a hard crash leaves the last-known status, which is the expected
+        # limitation of a profile-text indicator.
+        try:
+            await self._set_status_indicator(online=False)
+        except Exception:
+            pass
+
         pending_media_group_tasks = list(self._media_group_tasks.values())
         for task in pending_media_group_tasks:
             task.cancel()

tests/gateway/test_telegram_status_indicator.py

@@ -0,0 +1,120 @@
+"""Tests for the Telegram bot status indicator.
+
+Telegram bots have no real online/offline presence dot (that's a user-account
+feature). The closest Bot API surface is the bot's *short description* — the
+line shown under the bot's name in its profile. When `extra.status_indicator`
+is enabled, the adapter sets it to "Online" on connect and "Offline" on clean
+disconnect so users can tell whether the gateway is up.
+"""
+
+import sys
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from gateway.config import PlatformConfig
+
+
+def _ensure_telegram_mock():
+    if "telegram" in sys.modules and hasattr(sys.modules["telegram"], "__file__"):
+        return
+
+    telegram_mod = MagicMock()
+    telegram_mod.ext.ContextTypes.DEFAULT_TYPE = type(None)
+    telegram_mod.constants.ParseMode.MARKDOWN_V2 = "MarkdownV2"
+    telegram_mod.constants.ChatType.GROUP = "group"
+    telegram_mod.constants.ChatType.SUPERGROUP = "supergroup"
+    telegram_mod.constants.ChatType.CHANNEL = "channel"
+    telegram_mod.constants.ChatType.PRIVATE = "private"
+
+    for name in ("telegram", "telegram.ext", "telegram.constants", "telegram.request"):
+        sys.modules.setdefault(name, telegram_mod)
+
+
+_ensure_telegram_mock()
+
+from gateway.platforms.telegram import TelegramAdapter  # noqa: E402
+
+
+def _make_adapter(extra):
+    adapter = TelegramAdapter(PlatformConfig(enabled=True, token="***", extra=extra))
+    adapter._bot = MagicMock()
+    adapter._bot.set_my_short_description = AsyncMock()
+    return adapter
+
+
+def test_disabled_by_default():
+    adapter = _make_adapter(extra={})
+    assert adapter._status_indicator_enabled is False
+
+
+def test_enabled_via_extra():
+    adapter = _make_adapter(extra={"status_indicator": True})
+    assert adapter._status_indicator_enabled is True
+
+
+@pytest.mark.asyncio
+async def test_disabled_is_noop():
+    adapter = _make_adapter(extra={"status_indicator": False})
+    await adapter._set_status_indicator(online=True)
+    adapter._bot.set_my_short_description.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_online_sets_default_text():
+    adapter = _make_adapter(extra={"status_indicator": True})
+    await adapter._set_status_indicator(online=True)
+    adapter._bot.set_my_short_description.assert_awaited_once_with(
+        short_description="Online"
+    )
+
+
+@pytest.mark.asyncio
+async def test_offline_sets_default_text():
+    adapter = _make_adapter(extra={"status_indicator": True})
+    await adapter._set_status_indicator(online=False)
+    adapter._bot.set_my_short_description.assert_awaited_once_with(
+        short_description="Offline"
+    )
+
+
+@pytest.mark.asyncio
+async def test_custom_status_strings():
+    adapter = _make_adapter(
+        extra={
+            "status_indicator": True,
+            "status_online": "🟢 Gateway up",
+            "status_offline": "🔴 Gateway down",
+        }
+    )
+    await adapter._set_status_indicator(online=True)
+    adapter._bot.set_my_short_description.assert_awaited_once_with(
+        short_description="🟢 Gateway up"
+    )
+
+
+@pytest.mark.asyncio
+async def test_text_truncated_to_120_chars():
+    adapter = _make_adapter(
+        extra={"status_indicator": True, "status_online": "x" * 200}
+    )
+    await adapter._set_status_indicator(online=True)
+    _, kwargs = adapter._bot.set_my_short_description.call_args
+    assert len(kwargs["short_description"]) == 120
+
+
+@pytest.mark.asyncio
+async def test_noop_when_bot_is_none():
+    adapter = _make_adapter(extra={"status_indicator": True})
+    adapter._bot = None
+    # Must not raise even though there's no bot to call.
+    await adapter._set_status_indicator(online=True)
+
+
+@pytest.mark.asyncio
+async def test_api_failure_is_swallowed():
+    adapter = _make_adapter(extra={"status_indicator": True})
+    adapter._bot.set_my_short_description.side_effect = RuntimeError("flood wait")
+    # Best-effort: a Bot API failure must never propagate out of the helper,
+    # so it can't block connect/disconnect.
+    await adapter._set_status_indicator(online=True)

website/docs/user-guide/messaging/telegram.md

@@ -48,6 +48,37 @@ sethome - Set this chat as the home channel
 ```
 :::
 
+### Online/Offline status indicator (Optional)
+
+Telegram bots have no real online/offline presence dot — that green dot is a
+*user-account* feature, not something the Bot API exposes for bots. The closest
+surface is the bot's **short description** (the line shown under its name in the
+bot's profile).
+
+Enable `status_indicator` and Hermes sets that short description to **Online**
+when the gateway connects and **Offline** on a clean shutdown:
+
+```yaml
+gateway:
+  platforms:
+    telegram:
+      extra:
+        status_indicator: true
+        # Optional custom strings (defaults: "Online" / "Offline"):
+        status_online: "🟢 Online"
+        status_offline: "🔴 Offline"
+```
+
+Notes:
+
+- The short description is **global** to the bot (visible to all users), not
+  per-chat. Users see it on the bot's profile page, not as a live badge inside
+  an open chat.
+- Only a **clean** gateway shutdown (`/stop`, `disconnect`) writes "Offline".
+  A hard crash leaves the last-known status — the inherent limitation of a
+  profile-text indicator.
+- Off by default, since it mutates the bot's global profile.
+
 ## Step 3: Privacy Mode (Critical for Groups)
 
 Telegram bots have a **privacy mode** that is **enabled by default**. This is the single most common source of confusion when using bots in groups.