telegram

telegram

TelegramChannel — native Telegram Bot API adapter.

Classes

TelegramChannel

TelegramChannel(
    bot_token: str = "",
    *,
    allowed_chat_ids: str = "",
    parse_mode: str = "Markdown",
    bus: Optional[EventBus] = None,
)

Bases: BaseChannel

Native Telegram channel adapter using the Bot API.

PARAMETER	DESCRIPTION
bot_token	Telegram Bot API token. Falls back to TELEGRAM_BOT_TOKEN env var. TYPE: str DEFAULT: ''
allowed_chat_ids	Comma-separated list of chat IDs allowed to interact. TYPE: str DEFAULT: ''
parse_mode	Message parse mode (Markdown, HTML, etc.). TYPE: str DEFAULT: 'Markdown'
bus	Optional event bus for publishing channel events. TYPE: Optional[EventBus] DEFAULT: None

Source code in src/diapason/channels/telegram.py

def __init__(
    self,
    bot_token: str = "",
    *,
    allowed_chat_ids: str = "",
    parse_mode: str = "Markdown",
    bus: Optional[EventBus] = None,
) -> None:
    self._token = bot_token or os.environ.get("TELEGRAM_BOT_TOKEN", "")
    self._allowed_chat_ids = allowed_chat_ids
    self._parse_mode = parse_mode
    self._bus = bus
    self._handlers: List[ChannelHandler] = []
    self._status = ChannelStatus.DISCONNECTED
    self._listener_thread: Optional[threading.Thread] = None
    self._stop_event = threading.Event()

Methods:

connect

connect() -> None

Start listening for incoming messages via long polling.

Source code in src/diapason/channels/telegram.py

def connect(self) -> None:
    """Start listening for incoming messages via long polling."""
    if not self._token:
        logger.warning("No Telegram bot token configured")
        self._status = ChannelStatus.ERROR
        return

    self._stop_event.clear()
    self._status = ChannelStatus.CONNECTING

    try:
        from telegram.ext import ApplicationBuilder  # noqa: F401

        self._listener_thread = threading.Thread(
            target=self._poll_loop,
            daemon=True,
        )
        self._listener_thread.start()
        self._status = ChannelStatus.CONNECTED
        logger.info("Telegram channel connected (long polling)")
    except ImportError:
        # python-telegram-bot not installed — send-only mode
        logger.info(
            "python-telegram-bot not installed; send-only mode",
        )
        self._status = ChannelStatus.CONNECTED

disconnect

disconnect() -> None

Stop the listener thread.

Source code in src/diapason/channels/telegram.py

def disconnect(self) -> None:
    """Stop the listener thread."""
    self._stop_event.set()
    if self._listener_thread is not None:
        self._listener_thread.join(timeout=5.0)
        self._listener_thread = None
    self._status = ChannelStatus.DISCONNECTED

send

send(
    channel: str,
    content: str,
    *,
    conversation_id: str = "",
    metadata: Dict[str, Any] | None = None,
) -> bool

Send a message to a Telegram chat via the Bot API.

Source code in src/diapason/channels/telegram.py

def send(
    self,
    channel: str,
    content: str,
    *,
    conversation_id: str = "",
    metadata: Dict[str, Any] | None = None,
) -> bool:
    """Send a message to a Telegram chat via the Bot API."""
    if not self._token:
        logger.warning("Cannot send: no Telegram bot token")
        return False

    try:
        import httpx

        _TELEGRAM_MAX_LEN = 4096
        url = f"https://api.telegram.org/bot{self._token}/sendMessage"
        # Canonical channel send contract (see BaseChannel.send): the first
        # positional ``channel`` arg is the DESTINATION (the Telegram chat
        # id).  ``conversation_id`` is the inbound message id used as a
        # reply/thread reference (``reply_to_message_id``).  We fall back to
        # ``conversation_id`` as the chat id only when ``channel`` is empty,
        # for backwards compatibility with legacy callers that passed the
        # chat id via ``conversation_id``.
        chat_id = channel or conversation_id
        reply_to = conversation_id if (channel and conversation_id) else ""
        chunks = textwrap.wrap(
            content,
            width=_TELEGRAM_MAX_LEN,
            break_long_words=True,
            replace_whitespace=False,
        )
        for chunk in chunks:
            payload: Dict[str, Any] = {
                "chat_id": chat_id,
                "text": chunk,
            }
            if self._parse_mode:
                payload["parse_mode"] = self._parse_mode
            if reply_to:
                payload["reply_to_message_id"] = reply_to

            resp = httpx.post(url, json=payload, timeout=10.0)
            if resp.status_code >= 300:
                logger.warning(
                    "Telegram API returned status %d: %s",
                    resp.status_code,
                    resp.text,
                )
                return False
        self._publish_sent(channel, content, conversation_id)
        return True
    except Exception:
        logger.debug("Telegram send failed", exc_info=True)
        return False

status

status() -> ChannelStatus

Return the current connection status.

Source code in src/diapason/channels/telegram.py

def status(self) -> ChannelStatus:
    """Return the current connection status."""
    return self._status

list_channels

list_channels() -> List[str]

Return available channel identifiers.

Source code in src/diapason/channels/telegram.py

def list_channels(self) -> List[str]:
    """Return available channel identifiers."""
    return ["telegram"]

on_message

on_message(handler: ChannelHandler) -> None

Register a callback for incoming messages.

Source code in src/diapason/channels/telegram.py

def on_message(self, handler: ChannelHandler) -> None:
    """Register a callback for incoming messages."""
    self._handlers.append(handler)