refactor: streamline subagent prompt by reusing ContextBuilder and SkillsLoader

README.md

@@ -16,7 +16,7 @@
 
 ⚡️ Delivers core agent functionality in just **~4,000** lines of code — **99% smaller** than Clawdbot's 430k+ lines.
 
-📏 Real-time line count: **3,922 lines** (run `bash core_agent_lines.sh` to verify anytime)
+📏 Real-time line count: **3,927 lines** (run `bash core_agent_lines.sh` to verify anytime)
 
 ## 📢 News
 

nanobot/agent/subagent.py

@@ -104,8 +104,7 @@ class SubagentManager:
             tools.register(WebSearchTool(api_key=self.brave_api_key))
             tools.register(WebFetchTool())
             
-            # Build messages with subagent-specific prompt
-            system_prompt = self._build_subagent_prompt(task)
+            system_prompt = self._build_subagent_prompt()
             messages: list[dict[str, Any]] = [
                 {"role": "system", "content": system_prompt},
                 {"role": "user", "content": task},
@@ -204,42 +203,27 @@ Summarize this naturally for the user. Keep it brief (1-2 sentences). Do not men
         await self.bus.publish_inbound(msg)
         logger.debug("Subagent [{}] announced result to {}:{}", task_id, origin['channel'], origin['chat_id'])
     
-    def _build_subagent_prompt(self, task: str) -> str:
+    def _build_subagent_prompt(self) -> str:
         """Build a focused system prompt for the subagent."""
-        from datetime import datetime
-        import time as _time
-        now = datetime.now().strftime("%Y-%m-%d %H:%M (%A)")
-        tz = _time.strftime("%Z") or "UTC"
+        from nanobot.agent.context import ContextBuilder
+        from nanobot.agent.skills import SkillsLoader
 
-        return f"""# Subagent
+        time_ctx = ContextBuilder._build_runtime_context(None, None)
+        parts = [f"""# Subagent
 
-## Current Time
-{now} ({tz})
+{time_ctx}
 
 You are a subagent spawned by the main agent to complete a specific task.
-
-## Rules
-1. Stay focused - complete only the assigned task, nothing else
-2. Your final response will be reported back to the main agent
-3. Do not initiate conversations or take on side tasks
-4. Be concise but informative in your findings
-
-## What You Can Do
-- Read and write files in the workspace
-- Execute shell commands
-- Search the web and fetch web pages
-- Complete the task thoroughly
-
-## What You Cannot Do
-- Send messages directly to users (no message tool available)
-- Spawn other subagents
-- Access the main agent's conversation history
+Stay focused on the assigned task. Your final response will be reported back to the main agent.
 
 ## Workspace
-Your workspace is at: {self.workspace}
-Skills are available at: {self.workspace}/skills/ (read SKILL.md files as needed)
+{self.workspace}"""]
 
-When you have completed the task, provide a clear summary of your findings or actions."""
+        skills_summary = SkillsLoader(self.workspace).build_skills_summary()
+        if skills_summary:
+            parts.append(f"## Skills\n\nRead SKILL.md with read_file to use a skill.\n\n{skills_summary}")
+
+        return "\n\n".join(parts)
     
     async def cancel_by_session(self, session_key: str) -> int:
         """Cancel all subagents for the given session. Returns count cancelled."""