Merge branch 'main' into pr-1107

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: **3,897 lines** (run `bash core_agent_lines.sh` to verify anytime)
+📏 Real-time line count: **3,955 lines** (run `bash core_agent_lines.sh` to verify anytime)
 
 ## 📢 News
 

nanobot/agent/context.py

@@ -3,6 +3,8 @@
 import base64
 import mimetypes
 import platform
+import time
+from datetime import datetime
 from pathlib import Path
 from typing import Any
 
@@ -72,10 +74,6 @@ Skills with available="false" need dependencies installed first - you can try in
     
     def _get_identity(self) -> str:
         """Get the core identity section."""
-        from datetime import datetime
-        import time as _time
-        now = datetime.now().strftime("%Y-%m-%d %H:%M (%A)")
-        tz = _time.strftime("%Z") or "UTC"
         workspace_path = str(self.workspace.expanduser().resolve())
         system = platform.system()
         runtime = f"{'macOS' if system == 'Darwin' else system} {platform.machine()}, Python {platform.python_version()}"
@@ -84,9 +82,6 @@ Skills with available="false" need dependencies installed first - you can try in
 
 You are nanobot, a helpful AI assistant. 
 
-## Current Time
-{now} ({tz})
-
 ## Runtime
 {runtime}
 
@@ -109,6 +104,23 @@ Reply directly with text for conversations. Only use the 'message' tool to send
 - Remember important facts: write to {workspace_path}/memory/MEMORY.md
 - Recall past events: grep {workspace_path}/memory/HISTORY.md"""
 
+    @staticmethod
+    def _inject_runtime_context(
+        user_content: str | list[dict[str, Any]],
+        channel: str | None,
+        chat_id: str | None,
+    ) -> str | list[dict[str, Any]]:
+        """Append dynamic runtime context to the tail of the user message."""
+        now = datetime.now().strftime("%Y-%m-%d %H:%M (%A)")
+        tz = time.strftime("%Z") or "UTC"
+        lines = [f"Current Time: {now} ({tz})"]
+        if channel and chat_id:
+            lines += [f"Channel: {channel}", f"Chat ID: {chat_id}"]
+        block = "[Runtime Context]\n" + "\n".join(lines)
+        if isinstance(user_content, str):
+            return f"{user_content}\n\n{block}"
+        return [*user_content, {"type": "text", "text": block}]
+    
     def _load_bootstrap_files(self) -> str:
         """Load all bootstrap files from workspace."""
         parts = []
@@ -148,8 +160,6 @@ Reply directly with text for conversations. Only use the 'message' tool to send
 
         # System prompt
         system_prompt = self.build_system_prompt(skill_names)
-        if channel and chat_id:
-            system_prompt += f"\n\n## Current Session\nChannel: {channel}\nChat ID: {chat_id}"
         messages.append({"role": "system", "content": system_prompt})
 
         # History
@@ -157,6 +167,7 @@ Reply directly with text for conversations. Only use the 'message' tool to send
 
         # Current message (with optional image attachments)
         user_content = self._build_user_content(current_message, media)
+        user_content = self._inject_runtime_context(user_content, channel, chat_id)
         messages.append({"role": "user", "content": user_content})
 
         return messages

nanobot/agent/tools/registry.py

@@ -36,19 +36,7 @@ class ToolRegistry:
         return [tool.to_schema() for tool in self._tools.values()]
     
     async def execute(self, name: str, params: dict[str, Any]) -> str:
-        """
+        """Execute a tool by name with given parameters."""
-        Execute a tool by name with given parameters.
-        
-        Args:
-            name: Tool name.
-            params: Tool parameters.
-        
-        Returns:
-            Tool execution result as string.
-        
-        Raises:
-            KeyError: If tool not found.
-        """
         _HINT = "\n\n[Analyze the error above and try a different approach.]"
 
         tool = self._tools.get(name)

nanobot/agent/tools/spawn.py

@@ -9,12 +9,7 @@ if TYPE_CHECKING:
 
 
 class SpawnTool(Tool):
-    """
+    """Tool to spawn a subagent for background task execution."""
-    Tool to spawn a subagent for background task execution.
-    
-    The subagent runs asynchronously and announces its result back
-    to the main agent when complete.
-    """
     
     def __init__(self, manager: "SubagentManager"):
         self._manager = manager

nanobot/agent/tools/web.py

@@ -58,12 +58,16 @@ class WebSearchTool(Tool):
     }
     
     def __init__(self, api_key: str | None = None, max_results: int = 5):
-        self.api_key = api_key
+        self._init_api_key = api_key
         self.max_results = max_results
 
+    @property
+    def api_key(self) -> str:
+        """Resolve API key at call time so env/config changes are picked up."""
+        return self._init_api_key or os.environ.get("BRAVE_API_KEY", "")
+
     async def execute(self, query: str, count: int | None = None, **kwargs: Any) -> str:
-        api_key = self.api_key or os.environ.get("BRAVE_API_KEY", "")
+        if not self.api_key:
-        if not api_key:
             return (
                 "Error: Brave Search API key not configured. "
                 "Set it in ~/.nanobot/config.json under tools.web.search.apiKey "

tests/test_context_prompt_cache.py

@@ -0,0 +1,63 @@
+"""Tests for cache-friendly prompt construction."""
+
+from __future__ import annotations
+
+from datetime import datetime as real_datetime
+from pathlib import Path
+import datetime as datetime_module
+
+from nanobot.agent.context import ContextBuilder
+
+
+class _FakeDatetime(real_datetime):
+    current = real_datetime(2026, 2, 24, 13, 59)
+
+    @classmethod
+    def now(cls, tz=None):  # type: ignore[override]
+        return cls.current
+
+
+def _make_workspace(tmp_path: Path) -> Path:
+    workspace = tmp_path / "workspace"
+    workspace.mkdir(parents=True)
+    return workspace
+
+
+def test_system_prompt_stays_stable_when_clock_changes(tmp_path, monkeypatch) -> None:
+    """System prompt should not change just because wall clock minute changes."""
+    monkeypatch.setattr(datetime_module, "datetime", _FakeDatetime)
+
+    workspace = _make_workspace(tmp_path)
+    builder = ContextBuilder(workspace)
+
+    _FakeDatetime.current = real_datetime(2026, 2, 24, 13, 59)
+    prompt1 = builder.build_system_prompt()
+
+    _FakeDatetime.current = real_datetime(2026, 2, 24, 14, 0)
+    prompt2 = builder.build_system_prompt()
+
+    assert prompt1 == prompt2
+
+
+def test_runtime_context_is_appended_to_current_user_message(tmp_path) -> None:
+    """Dynamic runtime details should be added at the tail user message, not system."""
+    workspace = _make_workspace(tmp_path)
+    builder = ContextBuilder(workspace)
+
+    messages = builder.build_messages(
+        history=[],
+        current_message="Return exactly: OK",
+        channel="cli",
+        chat_id="direct",
+    )
+
+    assert messages[0]["role"] == "system"
+    assert "## Current Session" not in messages[0]["content"]
+
+    assert messages[-1]["role"] == "user"
+    user_content = messages[-1]["content"]
+    assert isinstance(user_content, str)
+    assert "Return exactly: OK" in user_content
+    assert "Current Time:" in user_content
+    assert "Channel: cli" in user_content
+    assert "Chat ID: direct" in user_content