From ec55f7791256cfcec28d947296247aac72f5701b Mon Sep 17 00:00:00 2001
From: Re-bin <xubinrencs@gmail.com>
Date: Tue, 24 Feb 2026 11:04:56 +0000
Subject: [PATCH] fix(heartbeat): replace HEARTBEAT_OK token with virtual
 tool-call decision

---
 nanobot/cli/commands.py      |  17 ++--
 nanobot/config/schema.py     |   8 ++
 nanobot/heartbeat/service.py | 162 +++++++++++++++++++++--------------
 3 files changed, 117 insertions(+), 70 deletions(-)

diff --git a/nanobot/cli/commands.py b/nanobot/cli/commands.py
index 90b9f44..ca71694 100644
--- a/nanobot/cli/commands.py
+++ b/nanobot/cli/commands.py
@@ -360,19 +360,19 @@ def gateway(
         return "cli", "direct"
 
     # Create heartbeat service
-    async def on_heartbeat(prompt: str) -> str:
-        """Execute heartbeat through the agent."""
+    async def on_heartbeat_execute(tasks: str) -> str:
+        """Phase 2: execute heartbeat tasks through the full agent loop."""
         channel, chat_id = _pick_heartbeat_target()
 
         async def _silent(*_args, **_kwargs):
             pass
 
         return await agent.process_direct(
-            prompt,
+            tasks,
             session_key="heartbeat",
             channel=channel,
             chat_id=chat_id,
-            on_progress=_silent,  # suppress: heartbeat should not push progress to external channels
+            on_progress=_silent,
         )
 
     async def on_heartbeat_notify(response: str) -> None:
@@ -383,12 +383,15 @@ def gateway(
             return  # No external channel available to deliver to
         await bus.publish_outbound(OutboundMessage(channel=channel, chat_id=chat_id, content=response))
 
+    hb_cfg = config.gateway.heartbeat
     heartbeat = HeartbeatService(
         workspace=config.workspace_path,
-        on_heartbeat=on_heartbeat,
+        provider=provider,
+        model=agent.model,
+        on_execute=on_heartbeat_execute,
         on_notify=on_heartbeat_notify,
-        interval_s=30 * 60,  # 30 minutes
-        enabled=True
+        interval_s=hb_cfg.interval_s,
+        enabled=hb_cfg.enabled,
     )
     
     if channels.enabled_channels:
diff --git a/nanobot/config/schema.py b/nanobot/config/schema.py
index fe8dd83..215f38d 100644
--- a/nanobot/config/schema.py
+++ b/nanobot/config/schema.py
@@ -228,11 +228,19 @@ class ProvidersConfig(Base):
     github_copilot: ProviderConfig = Field(default_factory=ProviderConfig)  # Github Copilot (OAuth)
 
 
+class HeartbeatConfig(Base):
+    """Heartbeat service configuration."""
+
+    enabled: bool = True
+    interval_s: int = 30 * 60  # 30 minutes
+
+
 class GatewayConfig(Base):
     """Gateway/server configuration."""
 
     host: str = "0.0.0.0"
     port: int = 18790
+    heartbeat: HeartbeatConfig = Field(default_factory=HeartbeatConfig)
 
 
 class WebSearchConfig(Base):
diff --git a/nanobot/heartbeat/service.py b/nanobot/heartbeat/service.py
index cb1a1c7..e534017 100644
--- a/nanobot/heartbeat/service.py
+++ b/nanobot/heartbeat/service.py
@@ -1,80 +1,110 @@
 """Heartbeat service - periodic agent wake-up to check for tasks."""
 
+from __future__ import annotations
+
 import asyncio
 from pathlib import Path
-from typing import Any, Callable, Coroutine
+from typing import TYPE_CHECKING, Any, Callable, Coroutine
 
 from loguru import logger
 
-# Default interval: 30 minutes
-DEFAULT_HEARTBEAT_INTERVAL_S = 30 * 60
+if TYPE_CHECKING:
+    from nanobot.providers.base import LLMProvider
 
-# Token the agent replies with when there is nothing to report
-HEARTBEAT_OK_TOKEN = "HEARTBEAT_OK"
-
-# The prompt sent to agent during heartbeat
-HEARTBEAT_PROMPT = (
-    "Read HEARTBEAT.md in your workspace and follow any instructions listed there. "
-    f"If nothing needs attention, reply with exactly: {HEARTBEAT_OK_TOKEN}"
-)
-
-
-def _is_heartbeat_empty(content: str | None) -> bool:
-    """Check if HEARTBEAT.md has no actionable content."""
-    if not content:
-        return True
-    
-    # Lines to skip: empty, headers, HTML comments, empty checkboxes
-    skip_patterns = {"- [ ]", "* [ ]", "- [x]", "* [x]"}
-    
-    for line in content.split("\n"):
-        line = line.strip()
-        if not line or line.startswith("#") or line.startswith("<!--") or line in skip_patterns:
-            continue
-        return False  # Found actionable content
-    
-    return True
+_HEARTBEAT_TOOL = [
+    {
+        "type": "function",
+        "function": {
+            "name": "heartbeat",
+            "description": "Report heartbeat decision after reviewing tasks.",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                    "action": {
+                        "type": "string",
+                        "enum": ["skip", "run"],
+                        "description": "skip = nothing to do, run = has active tasks",
+                    },
+                    "tasks": {
+                        "type": "string",
+                        "description": "Natural-language summary of active tasks (required for run)",
+                    },
+                },
+                "required": ["action"],
+            },
+        },
+    }
+]
 
 
 class HeartbeatService:
     """
     Periodic heartbeat service that wakes the agent to check for tasks.
 
-    The agent reads HEARTBEAT.md from the workspace and executes any tasks
-    listed there. If it has something to report, the response is forwarded
-    to the user via on_notify. If nothing needs attention, the agent replies
-    HEARTBEAT_OK and the response is silently dropped.
+    Phase 1 (decision): reads HEARTBEAT.md and asks the LLM — via a virtual
+    tool call — whether there are active tasks.  This avoids free-text parsing
+    and the unreliable HEARTBEAT_OK token.
+
+    Phase 2 (execution): only triggered when Phase 1 returns ``run``.  The
+    ``on_execute`` callback runs the task through the full agent loop and
+    returns the result to deliver.
     """
 
     def __init__(
         self,
         workspace: Path,
-        on_heartbeat: Callable[[str], Coroutine[Any, Any, str]] | None = None,
+        provider: LLMProvider,
+        model: str,
+        on_execute: Callable[[str], Coroutine[Any, Any, str]] | None = None,
         on_notify: Callable[[str], Coroutine[Any, Any, None]] | None = None,
-        interval_s: int = DEFAULT_HEARTBEAT_INTERVAL_S,
+        interval_s: int = 30 * 60,
         enabled: bool = True,
     ):
         self.workspace = workspace
-        self.on_heartbeat = on_heartbeat
+        self.provider = provider
+        self.model = model
+        self.on_execute = on_execute
         self.on_notify = on_notify
         self.interval_s = interval_s
         self.enabled = enabled
         self._running = False
         self._task: asyncio.Task | None = None
-    
+
     @property
     def heartbeat_file(self) -> Path:
         return self.workspace / "HEARTBEAT.md"
-    
+
     def _read_heartbeat_file(self) -> str | None:
-        """Read HEARTBEAT.md content."""
         if self.heartbeat_file.exists():
             try:
                 return self.heartbeat_file.read_text(encoding="utf-8")
             except Exception:
                 return None
         return None
-    
+
+    async def _decide(self, content: str) -> tuple[str, str]:
+        """Phase 1: ask LLM to decide skip/run via virtual tool call.
+
+        Returns (action, tasks) where action is 'skip' or 'run'.
+        """
+        response = await self.provider.chat(
+            messages=[
+                {"role": "system", "content": "You are a heartbeat agent. Call the heartbeat tool to report your decision."},
+                {"role": "user", "content": (
+                    "Review the following HEARTBEAT.md and decide whether there are active tasks.\n\n"
+                    f"{content}"
+                )},
+            ],
+            tools=_HEARTBEAT_TOOL,
+            model=self.model,
+        )
+
+        if not response.has_tool_calls:
+            return "skip", ""
+
+        args = response.tool_calls[0].arguments
+        return args.get("action", "skip"), args.get("tasks", "")
+
     async def start(self) -> None:
         """Start the heartbeat service."""
         if not self.enabled:
@@ -83,18 +113,18 @@ class HeartbeatService:
         if self._running:
             logger.warning("Heartbeat already running")
             return
-        
+
         self._running = True
         self._task = asyncio.create_task(self._run_loop())
         logger.info("Heartbeat started (every {}s)", self.interval_s)
-    
+
     def stop(self) -> None:
         """Stop the heartbeat service."""
         self._running = False
         if self._task:
             self._task.cancel()
             self._task = None
-    
+
     async def _run_loop(self) -> None:
         """Main heartbeat loop."""
         while self._running:
@@ -106,32 +136,38 @@ class HeartbeatService:
                 break
             except Exception as e:
                 logger.error("Heartbeat error: {}", e)
-    
+
     async def _tick(self) -> None:
         """Execute a single heartbeat tick."""
         content = self._read_heartbeat_file()
-        
-        # Skip if HEARTBEAT.md is empty or doesn't exist
-        if _is_heartbeat_empty(content):
-            logger.debug("Heartbeat: no tasks (HEARTBEAT.md empty)")
+        if not content:
+            logger.debug("Heartbeat: HEARTBEAT.md missing or empty")
             return
-        
+
         logger.info("Heartbeat: checking for tasks...")
-        
-        if self.on_heartbeat:
-            try:
-                response = await self.on_heartbeat(HEARTBEAT_PROMPT)
-                if HEARTBEAT_OK_TOKEN in response.upper():
-                    logger.info("Heartbeat: OK (nothing to report)")
-                else:
+
+        try:
+            action, tasks = await self._decide(content)
+
+            if action != "run":
+                logger.info("Heartbeat: OK (nothing to report)")
+                return
+
+            logger.info("Heartbeat: tasks found, executing...")
+            if self.on_execute:
+                response = await self.on_execute(tasks)
+                if response and self.on_notify:
                     logger.info("Heartbeat: completed, delivering response")
-                    if self.on_notify:
-                        await self.on_notify(response)
-            except Exception:
-                logger.exception("Heartbeat execution failed")
-    
+                    await self.on_notify(response)
+        except Exception:
+            logger.exception("Heartbeat execution failed")
+
     async def trigger_now(self) -> str | None:
         """Manually trigger a heartbeat."""
-        if self.on_heartbeat:
-            return await self.on_heartbeat(HEARTBEAT_PROMPT)
-        return None
+        content = self._read_heartbeat_file()
+        if not content:
+            return None
+        action, tasks = await self._decide(content)
+        if action != "run" or not self.on_execute:
+            return None
+        return await self.on_execute(tasks)