diff --git a/cli.py b/cli.py
index 2bb3cfa..5506d37 100755
--- a/cli.py
+++ b/cli.py
@@ -174,7 +174,14 @@ def cmd_doctor(args):
     except Exception:
         checks.append(("Ollama reachable", False))
 
-    # 10. Discord connection (bot PID running)
+    # 10. Telegram token (optional)
+    tg_token = get_secret("telegram_token")
+    if tg_token:
+        checks.append(("Telegram token in keyring", True))
+    else:
+        checks.append(("Telegram token (optional)", True))  # not required
+
+    # 11. Discord connection (bot PID running)
     pid_ok = False
     if PID_FILE.exists():
         try:
diff --git a/config.json b/config.json
index f95522a..fe1d3e1 100644
--- a/config.json
+++ b/config.json
@@ -1,11 +1,17 @@
 {
   "bot": {
     "name": "Echo",
-    "default_model": "sonnet",
-    "owner": null,
+    "default_model": "opus",
+    "owner": "949388626146517022",
     "admins": []
   },
-  "channels": {},
+  "channels": {
+    "echo-core": {
+      "id": "1471916752119009432",
+      "default_model": "opus"
+    }
+  },
+  "telegram_channels": {},
   "heartbeat": {
     "enabled": true,
     "interval_minutes": 30
@@ -20,4 +26,4 @@
     "logs": "logs/",
     "sessions": "sessions/"
   }
-}
\ No newline at end of file
+}
diff --git a/requirements.txt b/requirements.txt
index eadbb4c..b767c8b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 discord.py>=2.3
+python-telegram-bot>=21.0
 apscheduler>=3.10
 keyring>=25.0
 keyrings.alt>=5.0
diff --git a/src/adapters/telegram_bot.py b/src/adapters/telegram_bot.py
new file mode 100644
index 0000000..a2046e4
--- /dev/null
+++ b/src/adapters/telegram_bot.py
@@ -0,0 +1,368 @@
+"""Telegram bot adapter — commands and message handlers."""
+
+import asyncio
+import logging
+
+from telegram import Update, InlineKeyboardButton, InlineKeyboardMarkup
+from telegram.constants import ChatAction, ChatType
+from telegram.ext import (
+    Application,
+    CallbackQueryHandler,
+    CommandHandler,
+    ContextTypes,
+    MessageHandler,
+    filters,
+)
+
+from src.config import Config
+from src.claude_session import (
+    clear_session,
+    get_active_session,
+    set_session_model,
+    VALID_MODELS,
+)
+from src.router import route_message
+
+logger = logging.getLogger("echo-core.telegram")
+_security_log = logging.getLogger("echo-core.security")
+
+# Module-level config reference, set by create_telegram_bot()
+_config: Config | None = None
+
+
+def _get_config() -> Config:
+    """Return the module-level config, raising if not initialized."""
+    if _config is None:
+        raise RuntimeError("Bot not initialized — call create_telegram_bot() first")
+    return _config
+
+
+# --- Authorization helpers ---
+
+
+def is_owner(user_id: int) -> bool:
+    """Check if user_id matches config bot.owner."""
+    owner = _get_config().get("bot.owner")
+    return str(user_id) == str(owner)
+
+
+def is_admin(user_id: int) -> bool:
+    """Check if user_id is owner or in admins list."""
+    if is_owner(user_id):
+        return True
+    admins = _get_config().get("bot.admins", [])
+    return str(user_id) in admins
+
+
+def is_registered_chat(chat_id: int) -> bool:
+    """Check if Telegram chat_id is in any registered channel entry."""
+    channels = _get_config().get("telegram_channels", {})
+    return any(ch.get("id") == str(chat_id) for ch in channels.values())
+
+
+def _channel_alias_for_chat(chat_id: int) -> str | None:
+    """Resolve a Telegram chat ID to its config alias."""
+    channels = _get_config().get("telegram_channels", {})
+    for alias, info in channels.items():
+        if info.get("id") == str(chat_id):
+            return alias
+    return None
+
+
+# --- Message splitting helper ---
+
+
+def split_message(text: str, limit: int = 4096) -> list[str]:
+    """Split text into chunks that fit Telegram's message limit."""
+    if len(text) <= limit:
+        return [text]
+
+    chunks = []
+    while text:
+        if len(text) <= limit:
+            chunks.append(text)
+            break
+        split_at = text.rfind("\n", 0, limit)
+        if split_at == -1:
+            split_at = limit
+        chunks.append(text[:split_at])
+        text = text[split_at:].lstrip("\n")
+    return chunks
+
+
+# --- Command handlers ---
+
+
+async def cmd_start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /start — welcome message."""
+    await update.message.reply_text(
+        "Echo Core — Telegram adapter.\n"
+        "Send a message to chat with Claude.\n"
+        "Use /help for available commands."
+    )
+
+
+async def cmd_help(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /help — list commands."""
+    lines = [
+        "*Echo Commands*",
+        "/start — Welcome message",
+        "/help — Show this help",
+        "/clear — Clear the session for this chat",
+        "/status — Show session status",
+        "/model — View/change AI model",
+        "/register <alias> — Register this chat (owner only)",
+    ]
+    await update.message.reply_text("\n".join(lines), parse_mode="Markdown")
+
+
+async def cmd_clear(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /clear — clear session for this chat."""
+    chat_id = str(update.effective_chat.id)
+    default_model = _get_config().get("bot.default_model", "sonnet")
+    removed = clear_session(chat_id)
+    if removed:
+        await update.message.reply_text(
+            f"Session cleared. Model reset to {default_model}."
+        )
+    else:
+        await update.message.reply_text("No active session for this chat.")
+
+
+async def cmd_status(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /status — show session status."""
+    chat_id = str(update.effective_chat.id)
+    session = get_active_session(chat_id)
+    if not session:
+        await update.message.reply_text("No active session.")
+        return
+
+    model = session.get("model", "?")
+    sid = session.get("session_id", "?")[:8]
+    count = session.get("message_count", 0)
+    in_tok = session.get("total_input_tokens", 0)
+    out_tok = session.get("total_output_tokens", 0)
+
+    await update.message.reply_text(
+        f"Model: {model}\n"
+        f"Session: {sid}\n"
+        f"Messages: {count}\n"
+        f"Tokens: {in_tok} in / {out_tok} out"
+    )
+
+
+async def cmd_model(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /model — view or change model with inline keyboard."""
+    chat_id = str(update.effective_chat.id)
+    args = context.args
+
+    if args:
+        # /model opus — change model directly
+        choice = args[0].lower()
+        if choice not in VALID_MODELS:
+            await update.message.reply_text(
+                f"Invalid model '{choice}'. Choose from: {', '.join(sorted(VALID_MODELS))}"
+            )
+            return
+
+        session = get_active_session(chat_id)
+        if session:
+            set_session_model(chat_id, choice)
+        else:
+            from src.claude_session import _load_sessions, _save_sessions
+            from datetime import datetime, timezone
+
+            sessions = _load_sessions()
+            sessions[chat_id] = {
+                "session_id": "",
+                "model": choice,
+                "created_at": datetime.now(timezone.utc).isoformat(),
+                "last_message_at": datetime.now(timezone.utc).isoformat(),
+                "message_count": 0,
+            }
+            _save_sessions(sessions)
+        await update.message.reply_text(f"Model changed to *{choice}*.", parse_mode="Markdown")
+        return
+
+    # No args — show current model + inline keyboard
+    session = get_active_session(chat_id)
+    if session:
+        current = session.get("model", "?")
+    else:
+        current = _get_config().get("bot.default_model", "sonnet")
+
+    keyboard = [
+        [
+            InlineKeyboardButton(
+                f"{'> ' if m == current else ''}{m}",
+                callback_data=f"model:{m}",
+            )
+            for m in sorted(VALID_MODELS)
+        ]
+    ]
+    await update.message.reply_text(
+        f"Current model: *{current}*\nSelect a model:",
+        reply_markup=InlineKeyboardMarkup(keyboard),
+        parse_mode="Markdown",
+    )
+
+
+async def callback_model(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle inline keyboard callback for model selection."""
+    query = update.callback_query
+    await query.answer()
+
+    choice = query.data.replace("model:", "")
+    if choice not in VALID_MODELS:
+        return
+
+    chat_id = str(query.message.chat_id)
+    session = get_active_session(chat_id)
+    if session:
+        set_session_model(chat_id, choice)
+    else:
+        from src.claude_session import _load_sessions, _save_sessions
+        from datetime import datetime, timezone
+
+        sessions = _load_sessions()
+        sessions[chat_id] = {
+            "session_id": "",
+            "model": choice,
+            "created_at": datetime.now(timezone.utc).isoformat(),
+            "last_message_at": datetime.now(timezone.utc).isoformat(),
+            "message_count": 0,
+        }
+        _save_sessions(sessions)
+
+    await query.edit_message_text(f"Model changed to *{choice}*.", parse_mode="Markdown")
+
+
+async def cmd_register(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Handle /register <alias> — register current chat (owner only)."""
+    user_id = update.effective_user.id
+    if not is_owner(user_id):
+        _security_log.warning(
+            "Unauthorized owner command /register by user=%s (%s)",
+            user_id, update.effective_user.username,
+        )
+        await update.message.reply_text("Owner only.")
+        return
+
+    if not context.args:
+        await update.message.reply_text("Usage: /register <alias>")
+        return
+
+    alias = context.args[0].lower()
+    chat_id = str(update.effective_chat.id)
+
+    config = _get_config()
+    channels = config.get("telegram_channels", {})
+    if alias in channels:
+        await update.message.reply_text(f"Alias '{alias}' already registered.")
+        return
+
+    channels[alias] = {"id": chat_id, "default_model": "sonnet"}
+    config.set("telegram_channels", channels)
+    config.save()
+
+    await update.message.reply_text(
+        f"Chat registered as '{alias}' (ID: {chat_id})."
+    )
+
+
+# --- Message handler ---
+
+
+async def handle_message(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Process incoming text messages — route to Claude."""
+    message = update.message
+    if not message or not message.text:
+        return
+
+    user_id = update.effective_user.id
+    chat_id = update.effective_chat.id
+    chat_type = update.effective_chat.type
+
+    # Private chat: only admins
+    if chat_type == ChatType.PRIVATE:
+        if not is_admin(user_id):
+            _security_log.warning(
+                "Unauthorized Telegram DM from user=%s (%s): %s",
+                user_id, update.effective_user.username,
+                message.text[:100],
+            )
+            return
+
+    # Group chat: only registered chats, and bot must be mentioned or replied to
+    elif chat_type in (ChatType.GROUP, ChatType.SUPERGROUP):
+        if not is_registered_chat(chat_id):
+            return
+
+        # In groups, only respond when mentioned or replied to
+        bot_username = context.bot.username
+        is_reply_to_bot = (
+            message.reply_to_message
+            and message.reply_to_message.from_user
+            and message.reply_to_message.from_user.id == context.bot.id
+        )
+        is_mention = bot_username and f"@{bot_username}" in message.text
+
+        if not is_reply_to_bot and not is_mention:
+            return
+
+    else:
+        return
+
+    text = message.text
+    # Remove bot mention from text if present
+    bot_username = context.bot.username
+    if bot_username:
+        text = text.replace(f"@{bot_username}", "").strip()
+
+    if not text:
+        return
+
+    logger.info(
+        "Telegram message from %s (%s) in chat %s: %s",
+        user_id, update.effective_user.username,
+        chat_id, text[:100],
+    )
+
+    # Show typing indicator
+    await context.bot.send_chat_action(chat_id=chat_id, action=ChatAction.TYPING)
+
+    try:
+        response, _is_cmd = await asyncio.to_thread(
+            route_message, str(chat_id), str(user_id), text
+        )
+
+        chunks = split_message(response)
+        for chunk in chunks:
+            await message.reply_text(chunk)
+    except Exception:
+        logger.exception("Error processing Telegram message from %s", user_id)
+        await message.reply_text("Sorry, something went wrong processing your message.")
+
+
+# --- Factory ---
+
+
+def create_telegram_bot(config: Config, token: str) -> Application:
+    """Create and configure the Telegram bot with all handlers."""
+    global _config
+    _config = config
+
+    app = Application.builder().token(token).build()
+
+    app.add_handler(CommandHandler("start", cmd_start))
+    app.add_handler(CommandHandler("help", cmd_help))
+    app.add_handler(CommandHandler("clear", cmd_clear))
+    app.add_handler(CommandHandler("status", cmd_status))
+    app.add_handler(CommandHandler("model", cmd_model))
+    app.add_handler(CommandHandler("register", cmd_register))
+    app.add_handler(CallbackQueryHandler(callback_model, pattern="^model:"))
+    app.add_handler(
+        MessageHandler(filters.TEXT & ~filters.COMMAND, handle_message)
+    )
+
+    return app
diff --git a/src/main.py b/src/main.py
index 6f66a2d..e581fc5 100644
--- a/src/main.py
+++ b/src/main.py
@@ -108,6 +108,16 @@ def main():
             "Heartbeat registered (every %d min)", interval_min
         )
 
+    # Telegram bot (optional — only if telegram_token exists)
+    telegram_token = get_secret("telegram_token")
+    telegram_app = None
+    if telegram_token:
+        from src.adapters.telegram_bot import create_telegram_bot
+        telegram_app = create_telegram_bot(config, telegram_token)
+        logger.info("Telegram bot configured")
+    else:
+        logger.info("No telegram_token — Telegram bot disabled")
+
     # PID file
     PID_FILE.write_text(str(os.getpid()))
 
@@ -122,8 +132,27 @@ def main():
     signal.signal(signal.SIGTERM, handle_signal)
     signal.signal(signal.SIGINT, handle_signal)
 
+    async def _run_all():
+        """Run Discord + Telegram bots concurrently."""
+        tasks = [asyncio.create_task(client.start(token))]
+        if telegram_app:
+            async def _run_telegram():
+                await telegram_app.initialize()
+                await telegram_app.start()
+                await telegram_app.updater.start_polling()
+                logger.info("Telegram bot started polling")
+                try:
+                    while True:
+                        await asyncio.sleep(3600)
+                except asyncio.CancelledError:
+                    await telegram_app.updater.stop()
+                    await telegram_app.stop()
+                    await telegram_app.shutdown()
+            tasks.append(asyncio.create_task(_run_telegram()))
+        await asyncio.gather(*tasks)
+
     try:
-        loop.run_until_complete(client.start(token))
+        loop.run_until_complete(_run_all())
     except KeyboardInterrupt:
         loop.run_until_complete(scheduler.stop())
         loop.run_until_complete(client.close())
diff --git a/tests/test_telegram_bot.py b/tests/test_telegram_bot.py
new file mode 100644
index 0000000..e9a76cb
--- /dev/null
+++ b/tests/test_telegram_bot.py
@@ -0,0 +1,432 @@
+"""Tests for src/adapters/telegram_bot.py — Telegram bot adapter."""
+
+import json
+import pytest
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from src.config import Config
+from src.adapters import telegram_bot
+from src.adapters.telegram_bot import (
+    create_telegram_bot,
+    is_admin,
+    is_owner,
+    is_registered_chat,
+    split_message,
+    cmd_start,
+    cmd_help,
+    cmd_clear,
+    cmd_status,
+    cmd_model,
+    cmd_register,
+    callback_model,
+    handle_message,
+)
+
+
+# --- Fixtures ---
+
+
+@pytest.fixture
+def tmp_config(tmp_path):
+    """Create a Config backed by a temp file with default data."""
+    data = {
+        "bot": {
+            "name": "Echo",
+            "default_model": "sonnet",
+            "owner": None,
+            "admins": [],
+        },
+        "channels": {},
+        "telegram_channels": {},
+    }
+    config_file = tmp_path / "config.json"
+    config_file.write_text(json.dumps(data, indent=2))
+    return Config(config_file)
+
+
+@pytest.fixture
+def owned_config(tmp_path):
+    """Config with owner and telegram channels set."""
+    data = {
+        "bot": {
+            "name": "Echo",
+            "default_model": "sonnet",
+            "owner": "111",
+            "admins": ["222"],
+        },
+        "channels": {},
+        "telegram_channels": {
+            "general": {"id": "900", "default_model": "sonnet"},
+        },
+    }
+    config_file = tmp_path / "config.json"
+    config_file.write_text(json.dumps(data, indent=2))
+    return Config(config_file)
+
+
+@pytest.fixture(autouse=True)
+def _set_config(tmp_config):
+    """Ensure module config is set for each test."""
+    telegram_bot._config = tmp_config
+    yield
+    telegram_bot._config = None
+
+
+@pytest.fixture
+def _set_owned(owned_config):
+    """Set owned config for specific tests."""
+    telegram_bot._config = owned_config
+    yield
+    telegram_bot._config = None
+
+
+def _mock_update(user_id=123, chat_id=456, text="hello", chat_type="private", username="testuser"):
+    """Create a mock telegram Update."""
+    update = MagicMock()
+    update.effective_user = MagicMock()
+    update.effective_user.id = user_id
+    update.effective_user.username = username
+    update.effective_chat = MagicMock()
+    update.effective_chat.id = chat_id
+    update.effective_chat.type = chat_type
+    update.message = MagicMock()
+    update.message.text = text
+    update.message.reply_text = AsyncMock()
+    update.message.reply_to_message = None
+    return update
+
+
+def _mock_context(bot_id=999, bot_username="echo_bot"):
+    """Create a mock context."""
+    context = MagicMock()
+    context.args = []
+    context.bot = MagicMock()
+    context.bot.id = bot_id
+    context.bot.username = bot_username
+    context.bot.send_chat_action = AsyncMock()
+    return context
+
+
+# --- Authorization helpers ---
+
+
+class TestIsOwner:
+    def test_is_owner_true(self, _set_owned):
+        assert is_owner(111) is True
+
+    def test_is_owner_false(self, _set_owned):
+        assert is_owner(999) is False
+
+    def test_is_owner_none_owner(self):
+        assert is_owner(123) is False
+
+
+class TestIsAdmin:
+    def test_is_admin_owner_is_admin(self, _set_owned):
+        assert is_admin(111) is True
+
+    def test_is_admin_listed(self, _set_owned):
+        assert is_admin(222) is True
+
+    def test_is_admin_not_listed(self, _set_owned):
+        assert is_admin(999) is False
+
+
+class TestIsRegisteredChat:
+    def test_is_registered_true(self, _set_owned):
+        assert is_registered_chat(900) is True
+
+    def test_is_registered_false(self, _set_owned):
+        assert is_registered_chat(000) is False
+
+    def test_is_registered_empty(self):
+        assert is_registered_chat(900) is False
+
+
+# --- split_message ---
+
+
+class TestSplitMessage:
+    def test_short_message_not_split(self):
+        assert split_message("hello") == ["hello"]
+
+    def test_long_message_split(self):
+        text = "a" * 8192
+        chunks = split_message(text, limit=4096)
+        assert len(chunks) == 2
+        assert all(len(c) <= 4096 for c in chunks)
+        assert "".join(chunks) == text
+
+    def test_split_at_newline(self):
+        text = "line1\n" * 1000
+        chunks = split_message(text, limit=100)
+        assert all(len(c) <= 100 for c in chunks)
+
+    def test_empty_string(self):
+        assert split_message("") == [""]
+
+
+# --- Command handlers ---
+
+
+class TestCmdStart:
+    @pytest.mark.asyncio
+    async def test_start_responds(self):
+        update = _mock_update()
+        context = _mock_context()
+        await cmd_start(update, context)
+        update.message.reply_text.assert_called_once()
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Echo Core" in msg
+
+
+class TestCmdHelp:
+    @pytest.mark.asyncio
+    async def test_help_responds(self):
+        update = _mock_update()
+        context = _mock_context()
+        await cmd_help(update, context)
+        update.message.reply_text.assert_called_once()
+        msg = update.message.reply_text.call_args[0][0]
+        assert "/clear" in msg
+        assert "/model" in msg
+
+
+class TestCmdClear:
+    @pytest.mark.asyncio
+    async def test_clear_no_session(self):
+        update = _mock_update()
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.clear_session", return_value=False):
+            await cmd_clear(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "No active session" in msg
+
+    @pytest.mark.asyncio
+    async def test_clear_with_session(self):
+        update = _mock_update()
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.clear_session", return_value=True):
+            await cmd_clear(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Session cleared" in msg
+
+
+class TestCmdStatus:
+    @pytest.mark.asyncio
+    async def test_status_no_session(self):
+        update = _mock_update()
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.get_active_session", return_value=None):
+            await cmd_status(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "No active session" in msg
+
+    @pytest.mark.asyncio
+    async def test_status_with_session(self):
+        update = _mock_update()
+        context = _mock_context()
+        session = {
+            "model": "opus",
+            "session_id": "sess-abc-12345678",
+            "message_count": 5,
+            "total_input_tokens": 1000,
+            "total_output_tokens": 500,
+        }
+        with patch("src.adapters.telegram_bot.get_active_session", return_value=session):
+            await cmd_status(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "opus" in msg
+        assert "5" in msg
+
+
+class TestCmdModel:
+    @pytest.mark.asyncio
+    async def test_model_with_arg(self, tmp_path, monkeypatch):
+        update = _mock_update()
+        context = _mock_context()
+        context.args = ["opus"]
+
+        # Need session dir for _save_sessions
+        sessions_dir = tmp_path / "sessions"
+        sessions_dir.mkdir()
+        from src import claude_session
+        monkeypatch.setattr(claude_session, "SESSIONS_DIR", sessions_dir)
+        monkeypatch.setattr(claude_session, "_SESSIONS_FILE", sessions_dir / "active.json")
+
+        with patch("src.adapters.telegram_bot.get_active_session", return_value=None):
+            await cmd_model(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "opus" in msg
+
+    @pytest.mark.asyncio
+    async def test_model_invalid(self):
+        update = _mock_update()
+        context = _mock_context()
+        context.args = ["gpt4"]
+        await cmd_model(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Invalid model" in msg
+
+    @pytest.mark.asyncio
+    async def test_model_keyboard(self):
+        update = _mock_update()
+        context = _mock_context()
+        context.args = []
+        with patch("src.adapters.telegram_bot.get_active_session", return_value=None):
+            await cmd_model(update, context)
+        call_kwargs = update.message.reply_text.call_args[1]
+        assert "reply_markup" in call_kwargs
+
+
+class TestCmdRegister:
+    @pytest.mark.asyncio
+    async def test_register_not_owner(self):
+        update = _mock_update(user_id=999)
+        context = _mock_context()
+        context.args = ["test"]
+        await cmd_register(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Owner only" in msg
+
+    @pytest.mark.asyncio
+    async def test_register_owner(self, _set_owned):
+        update = _mock_update(user_id=111, chat_id=777)
+        context = _mock_context()
+        context.args = ["mychat"]
+        await cmd_register(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "registered" in msg
+        assert "mychat" in msg
+
+    @pytest.mark.asyncio
+    async def test_register_no_args(self, _set_owned):
+        update = _mock_update(user_id=111)
+        context = _mock_context()
+        context.args = []
+        await cmd_register(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Usage" in msg
+
+
+# --- Message handler ---
+
+
+class TestHandleMessage:
+    @pytest.mark.asyncio
+    async def test_private_chat_admin(self, _set_owned):
+        update = _mock_update(user_id=111, chat_type="private", text="Hello Claude")
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.route_message", return_value=("Hi!", False)) as mock_route:
+            await handle_message(update, context)
+        mock_route.assert_called_once()
+        update.message.reply_text.assert_called_with("Hi!")
+
+    @pytest.mark.asyncio
+    async def test_private_chat_unauthorized(self, _set_owned):
+        update = _mock_update(user_id=999, chat_type="private", text="Hello")
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.route_message") as mock_route:
+            await handle_message(update, context)
+        mock_route.assert_not_called()
+        update.message.reply_text.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_group_chat_unregistered(self, _set_owned):
+        update = _mock_update(user_id=111, chat_id=999, chat_type="supergroup", text="Hello")
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.route_message") as mock_route:
+            await handle_message(update, context)
+        mock_route.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_group_chat_registered_mention(self, _set_owned):
+        update = _mock_update(
+            user_id=111, chat_id=900, chat_type="supergroup",
+            text="@echo_bot what is the weather?"
+        )
+        context = _mock_context(bot_username="echo_bot")
+        with patch("src.adapters.telegram_bot.route_message", return_value=("Sunny!", False)):
+            await handle_message(update, context)
+        update.message.reply_text.assert_called_with("Sunny!")
+
+    @pytest.mark.asyncio
+    async def test_group_chat_registered_no_mention(self, _set_owned):
+        update = _mock_update(
+            user_id=111, chat_id=900, chat_type="supergroup",
+            text="just chatting"
+        )
+        context = _mock_context(bot_username="echo_bot")
+        with patch("src.adapters.telegram_bot.route_message") as mock_route:
+            await handle_message(update, context)
+        mock_route.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_group_chat_reply_to_bot(self, _set_owned):
+        update = _mock_update(
+            user_id=111, chat_id=900, chat_type="supergroup",
+            text="follow up"
+        )
+        # Set up reply-to-bot
+        update.message.reply_to_message = MagicMock()
+        update.message.reply_to_message.from_user = MagicMock()
+        update.message.reply_to_message.from_user.id = 999  # bot id
+        context = _mock_context(bot_id=999)
+        with patch("src.adapters.telegram_bot.route_message", return_value=("Response", False)):
+            await handle_message(update, context)
+        update.message.reply_text.assert_called_with("Response")
+
+    @pytest.mark.asyncio
+    async def test_long_response_split(self, _set_owned):
+        update = _mock_update(user_id=111, chat_type="private", text="Hello")
+        context = _mock_context()
+        long_response = "x" * 8000
+        with patch("src.adapters.telegram_bot.route_message", return_value=(long_response, False)):
+            await handle_message(update, context)
+        assert update.message.reply_text.call_count == 2
+
+    @pytest.mark.asyncio
+    async def test_error_handling(self, _set_owned):
+        update = _mock_update(user_id=111, chat_type="private", text="Hello")
+        context = _mock_context()
+        with patch("src.adapters.telegram_bot.route_message", side_effect=Exception("boom")):
+            await handle_message(update, context)
+        msg = update.message.reply_text.call_args[0][0]
+        assert "Sorry" in msg
+
+
+# --- Security logging ---
+
+
+class TestSecurityLogging:
+    @pytest.mark.asyncio
+    async def test_unauthorized_dm_logged(self, _set_owned):
+        update = _mock_update(user_id=999, chat_type="private", text="hack attempt")
+        context = _mock_context()
+        with patch.object(telegram_bot._security_log, "warning") as mock_log:
+            await handle_message(update, context)
+            mock_log.assert_called_once()
+            assert "Unauthorized" in mock_log.call_args[0][0]
+
+    @pytest.mark.asyncio
+    async def test_unauthorized_register_logged(self):
+        update = _mock_update(user_id=999)
+        context = _mock_context()
+        context.args = ["test"]
+        with patch.object(telegram_bot._security_log, "warning") as mock_log:
+            await cmd_register(update, context)
+            mock_log.assert_called_once()
+
+
+# --- Factory ---
+
+
+class TestCreateTelegramBot:
+    def test_creates_application(self, tmp_config):
+        from telegram.ext import Application
+        app = create_telegram_bot(tmp_config, "fake-token-123")
+        assert isinstance(app, Application)
+
+    def test_sets_config(self, tmp_config):
+        create_telegram_bot(tmp_config, "fake-token-123")
+        assert telegram_bot._config is tmp_config