feat: auto-generate session titles after first exchange

After the first user→assistant exchange, Hermes now generates a short
descriptive session title via the auxiliary LLM (compression task config).
Title generation runs in a background thread so it never delays the
user-facing response.

Key behaviors:
- Fires only on the first 1-2 exchanges (checks user message count)
- Skips if a title already exists (user-set titles are never overwritten)
- Uses call_llm with compression task config (cheapest/fastest model)
- Truncates long messages to keep the title generation request small
- Cleans up LLM output: strips quotes, 'Title:' prefixes, enforces 80 char max
- Works in both CLI and gateway (Telegram/Discord/etc.)

Also updates /title (no args) to show the session ID alongside the title
in both CLI and gateway.

Implements #1426

agent/title_generator.py

@@ -0,0 +1,125 @@
+"""Auto-generate short session titles from the first user/assistant exchange.
+
+Runs asynchronously after the first response is delivered so it never
+adds latency to the user-facing reply.
+"""
+
+import logging
+import threading
+from typing import Optional
+
+from agent.auxiliary_client import call_llm
+
+logger = logging.getLogger(__name__)
+
+_TITLE_PROMPT = (
+    "Generate a short, descriptive title (3-7 words) for a conversation that starts with the "
+    "following exchange. The title should capture the main topic or intent. "
+    "Return ONLY the title text, nothing else. No quotes, no punctuation at the end, no prefixes."
+)
+
+
+def generate_title(user_message: str, assistant_response: str, timeout: float = 15.0) -> Optional[str]:
+    """Generate a session title from the first exchange.
+
+    Uses the auxiliary LLM client (cheapest/fastest available model).
+    Returns the title string or None on failure.
+    """
+    # Truncate long messages to keep the request small
+    user_snippet = user_message[:500] if user_message else ""
+    assistant_snippet = assistant_response[:500] if assistant_response else ""
+
+    messages = [
+        {"role": "system", "content": _TITLE_PROMPT},
+        {"role": "user", "content": f"User: {user_snippet}\n\nAssistant: {assistant_snippet}"},
+    ]
+
+    try:
+        response = call_llm(
+            task="compression",  # reuse compression task config (cheap/fast model)
+            messages=messages,
+            max_tokens=30,
+            temperature=0.3,
+            timeout=timeout,
+        )
+        title = (response.choices[0].message.content or "").strip()
+        # Clean up: remove quotes, trailing punctuation, prefixes like "Title: "
+        title = title.strip('"\'')
+        if title.lower().startswith("title:"):
+            title = title[6:].strip()
+        # Enforce reasonable length
+        if len(title) > 80:
+            title = title[:77] + "..."
+        return title if title else None
+    except Exception as e:
+        logger.debug("Title generation failed: %s", e)
+        return None
+
+
+def auto_title_session(
+    session_db,
+    session_id: str,
+    user_message: str,
+    assistant_response: str,
+) -> None:
+    """Generate and set a session title if one doesn't already exist.
+
+    Called in a background thread after the first exchange completes.
+    Silently skips if:
+    - session_db is None
+    - session already has a title (user-set or previously auto-generated)
+    - title generation fails
+    """
+    if not session_db or not session_id:
+        return
+
+    # Check if title already exists (user may have set one via /title before first response)
+    try:
+        existing = session_db.get_session_title(session_id)
+        if existing:
+            return
+    except Exception:
+        return
+
+    title = generate_title(user_message, assistant_response)
+    if not title:
+        return
+
+    try:
+        session_db.set_session_title(session_id, title)
+        logger.debug("Auto-generated session title: %s", title)
+    except Exception as e:
+        logger.debug("Failed to set auto-generated title: %s", e)
+
+
+def maybe_auto_title(
+    session_db,
+    session_id: str,
+    user_message: str,
+    assistant_response: str,
+    conversation_history: list,
+) -> None:
+    """Fire-and-forget title generation after the first exchange.
+
+    Only generates a title when:
+    - This appears to be the first user→assistant exchange
+    - No title is already set
+    """
+    if not session_db or not session_id or not user_message or not assistant_response:
+        return
+
+    # Count user messages in history to detect first exchange.
+    # conversation_history includes the exchange that just happened,
+    # so for a first exchange we expect exactly 1 user message
+    # (or 2 counting system). Be generous: generate on first 2 exchanges.
+    user_msg_count = sum(1 for m in (conversation_history or []) if m.get("role") == "user")
+    if user_msg_count > 2:
+        return
+
+    thread = threading.Thread(
+        target=auto_title_session,
+        args=(session_db, session_id, user_message, assistant_response),
+        daemon=True,
+        name="auto-title",
+    )
+    thread.start()

cli.py

@@ -3452,13 +3452,14 @@ class HermesCLI:
                 else:
                     _cprint("  Usage: /title <your session title>")
             else:
-                # Show current title if no argument given
+                # Show current title and session ID if no argument given
                 if self._session_db:
+                    _cprint(f"  Session ID: {self.session_id}")
                     session = self._session_db.get_session(self.session_id)
                     if session and session.get("title"):
-                        _cprint(f"  Session title: {session['title']}")
+                        _cprint(f"  Title: {session['title']}")
                     elif self._pending_title:
-                        _cprint(f"  Session title (pending): {self._pending_title}")
+                        _cprint(f"  Title (pending): {self._pending_title}")
                     else:
                         _cprint(f"  No title set. Usage: /title <your session title>")
                 else:
@@ -5384,6 +5385,20 @@ class HermesCLI:
             # Get the final response
             response = result.get("final_response", "") if result else ""
 
+            # Auto-generate session title after first exchange (non-blocking)
+            if response and result and not result.get("failed") and not result.get("partial"):
+                try:
+                    from agent.title_generator import maybe_auto_title
+                    maybe_auto_title(
+                        self._session_db,
+                        self.session_id,
+                        message,
+                        response,
+                        self.conversation_history,
+                    )
+                except Exception:
+                    pass
+
             # Handle failed or partial results (e.g., non-retryable errors, rate limits,
             # truncated output, invalid tool calls). Both "failed" and "partial" with
             # an empty final_response mean the agent couldn't produce a usable answer.

gateway/run.py

@@ -3328,12 +3328,12 @@ class GatewayRunner:
             except ValueError as e:
                 return f"⚠️ {e}"
         else:
-            # Show the current title
+            # Show the current title and session ID
             title = self._session_db.get_session_title(session_id)
             if title:
-                return f"📌 Session title: **{title}**"
+                return f"📌 Session: `{session_id}`\nTitle: **{title}**"
             else:
-                return "No title set. Usage: `/title My Session Name`"
+                return f"📌 Session: `{session_id}`\nNo title set. Usage: `/title My Session Name`"
 
     async def _handle_resume_command(self, event: MessageEvent) -> str:
         """Handle /resume command — switch to a previously-named session."""
@@ -4511,6 +4511,21 @@ class GatewayRunner:
 
             effective_session_id = getattr(agent, 'session_id', session_id) if agent else session_id
 
+            # Auto-generate session title after first exchange (non-blocking)
+            if final_response and self._session_db:
+                try:
+                    from agent.title_generator import maybe_auto_title
+                    all_msgs = result_holder[0].get("messages", []) if result_holder[0] else []
+                    maybe_auto_title(
+                        self._session_db,
+                        effective_session_id,
+                        message,
+                        final_response,
+                        all_msgs,
+                    )
+                except Exception:
+                    pass
+
             return {
                 "final_response": final_response,
                 "last_reasoning": result.get("last_reasoning"),

tests/agent/test_title_generator.py

@@ -0,0 +1,160 @@
+"""Tests for agent.title_generator — auto-generated session titles."""
+
+import threading
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from agent.title_generator import (
+    generate_title,
+    auto_title_session,
+    maybe_auto_title,
+)
+
+
+class TestGenerateTitle:
+    """Unit tests for generate_title()."""
+
+    def test_returns_title_on_success(self):
+        mock_response = MagicMock()
+        mock_response.choices = [MagicMock()]
+        mock_response.choices[0].message.content = "Debugging Python Import Errors"
+
+        with patch("agent.title_generator.call_llm", return_value=mock_response):
+            title = generate_title("help me fix this import", "Sure, let me check...")
+            assert title == "Debugging Python Import Errors"
+
+    def test_strips_quotes(self):
+        mock_response = MagicMock()
+        mock_response.choices = [MagicMock()]
+        mock_response.choices[0].message.content = '"Setting Up Docker Environment"'
+
+        with patch("agent.title_generator.call_llm", return_value=mock_response):
+            title = generate_title("how do I set up docker", "First install...")
+            assert title == "Setting Up Docker Environment"
+
+    def test_strips_title_prefix(self):
+        mock_response = MagicMock()
+        mock_response.choices = [MagicMock()]
+        mock_response.choices[0].message.content = "Title: Kubernetes Pod Debugging"
+
+        with patch("agent.title_generator.call_llm", return_value=mock_response):
+            title = generate_title("my pod keeps crashing", "Let me look...")
+            assert title == "Kubernetes Pod Debugging"
+
+    def test_truncates_long_titles(self):
+        mock_response = MagicMock()
+        mock_response.choices = [MagicMock()]
+        mock_response.choices[0].message.content = "A" * 100
+
+        with patch("agent.title_generator.call_llm", return_value=mock_response):
+            title = generate_title("question", "answer")
+            assert len(title) == 80
+            assert title.endswith("...")
+
+    def test_returns_none_on_empty_response(self):
+        mock_response = MagicMock()
+        mock_response.choices = [MagicMock()]
+        mock_response.choices[0].message.content = ""
+
+        with patch("agent.title_generator.call_llm", return_value=mock_response):
+            assert generate_title("question", "answer") is None
+
+    def test_returns_none_on_exception(self):
+        with patch("agent.title_generator.call_llm", side_effect=RuntimeError("no provider")):
+            assert generate_title("question", "answer") is None
+
+    def test_truncates_long_messages(self):
+        """Long user/assistant messages should be truncated in the LLM request."""
+        captured_kwargs = {}
+
+        def mock_call_llm(**kwargs):
+            captured_kwargs.update(kwargs)
+            resp = MagicMock()
+            resp.choices = [MagicMock()]
+            resp.choices[0].message.content = "Short Title"
+            return resp
+
+        with patch("agent.title_generator.call_llm", side_effect=mock_call_llm):
+            generate_title("x" * 1000, "y" * 1000)
+
+        # The user content in the messages should be truncated
+        user_content = captured_kwargs["messages"][1]["content"]
+        assert len(user_content) < 1100  # 500 + 500 + formatting
+
+
+class TestAutoTitleSession:
+    """Tests for auto_title_session() — the sync worker function."""
+
+    def test_skips_if_no_session_db(self):
+        auto_title_session(None, "sess-1", "hi", "hello")  # should not crash
+
+    def test_skips_if_title_exists(self):
+        db = MagicMock()
+        db.get_session_title.return_value = "Existing Title"
+
+        with patch("agent.title_generator.generate_title") as gen:
+            auto_title_session(db, "sess-1", "hi", "hello")
+            gen.assert_not_called()
+
+    def test_generates_and_sets_title(self):
+        db = MagicMock()
+        db.get_session_title.return_value = None
+
+        with patch("agent.title_generator.generate_title", return_value="New Title"):
+            auto_title_session(db, "sess-1", "hi", "hello")
+            db.set_session_title.assert_called_once_with("sess-1", "New Title")
+
+    def test_skips_if_generation_fails(self):
+        db = MagicMock()
+        db.get_session_title.return_value = None
+
+        with patch("agent.title_generator.generate_title", return_value=None):
+            auto_title_session(db, "sess-1", "hi", "hello")
+            db.set_session_title.assert_not_called()
+
+
+class TestMaybeAutoTitle:
+    """Tests for maybe_auto_title() — the fire-and-forget entry point."""
+
+    def test_skips_if_not_first_exchange(self):
+        """Should not fire for conversations with more than 2 user messages."""
+        db = MagicMock()
+        history = [
+            {"role": "user", "content": "first"},
+            {"role": "assistant", "content": "response 1"},
+            {"role": "user", "content": "second"},
+            {"role": "assistant", "content": "response 2"},
+            {"role": "user", "content": "third"},
+            {"role": "assistant", "content": "response 3"},
+        ]
+
+        with patch("agent.title_generator.auto_title_session") as mock_auto:
+            maybe_auto_title(db, "sess-1", "third", "response 3", history)
+            # Wait briefly for any thread to start
+            import time
+            time.sleep(0.1)
+            mock_auto.assert_not_called()
+
+    def test_fires_on_first_exchange(self):
+        """Should fire a background thread for the first exchange."""
+        db = MagicMock()
+        db.get_session_title.return_value = None
+        history = [
+            {"role": "user", "content": "hello"},
+            {"role": "assistant", "content": "hi there"},
+        ]
+
+        with patch("agent.title_generator.auto_title_session") as mock_auto:
+            maybe_auto_title(db, "sess-1", "hello", "hi there", history)
+            # Wait for the daemon thread to complete
+            import time
+            time.sleep(0.3)
+            mock_auto.assert_called_once_with(db, "sess-1", "hello", "hi there")
+
+    def test_skips_if_no_response(self):
+        db = MagicMock()
+        maybe_auto_title(db, "sess-1", "hello", "", [])  # empty response
+
+    def test_skips_if_no_session_db(self):
+        maybe_auto_title(None, "sess-1", "hello", "response", [])  # no db