feat(box): add host workspace mounting and sandbox_exec guidance

src/langbot/pkg/provider/runners/localagent.py

@@ -29,7 +29,13 @@ SANDBOX_EXEC_SYSTEM_GUIDANCE = (
     'When sandbox_exec is available, use it for exact calculations, statistics, structured data parsing, '
     'and code execution instead of estimating mentally. If the user provides numbers, tables, CSV-like text, '
     'JSON, or other data and asks for a computed answer, prefer running a short Python script in sandbox_exec '
-    'and then answer from the tool result.'
+    'and then answer from the tool result. Unless the user explicitly asks for the script, code, or implementation '
+    'details, do not include the generated script in the final answer; return the result and a brief explanation only.'
+)
+SANDBOX_EXEC_WORKSPACE_GUIDANCE = (
+    'A default host workspace is mounted at /workspace for file tasks. When the user asks to read, create, or '
+    'modify local files in the working directory, use sandbox_exec with /workspace paths directly; do not ask the '
+    'user for sandbox parameters such as host_path unless they explicitly need a different directory.'
 )
 
 
@@ -37,6 +43,15 @@ SANDBOX_EXEC_SYSTEM_GUIDANCE = (
 class LocalAgentRunner(runner.RequestRunner):
     """Local agent request runner"""
 
+    def _build_sandbox_system_guidance(self) -> str:
+        guidance = SANDBOX_EXEC_SYSTEM_GUIDANCE
+        default_host_workspace = str(
+            getattr(getattr(self.ap, 'instance_config', None), 'data', {}).get('box', {}).get('default_host_workspace', '')
+        ).strip()
+        if default_host_workspace:
+            guidance = f'{guidance} {SANDBOX_EXEC_WORKSPACE_GUIDANCE}'
+        return guidance
+
     def _build_request_messages(
         self,
         query: pipeline_query.Query,
@@ -48,7 +63,7 @@ class LocalAgentRunner(runner.RequestRunner):
             req_messages.append(
                 provider_message.Message(
                     role='system',
-                    content=SANDBOX_EXEC_SYSTEM_GUIDANCE,
+                    content=self._build_sandbox_system_guidance(),
                 )
             )
 

src/langbot/pkg/provider/tools/loaders/native.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import json
+
 import langbot_plugin.api.entities.builtin.resource.tool as resource_tool
 from langbot_plugin.api.entities.events import pipeline_query
 
@@ -18,6 +20,11 @@ class NativeToolLoader(loader.ToolLoader):
     async def invoke_tool(self, name: str, parameters: dict, query: pipeline_query.Query):
         if name != self.SANDBOX_EXEC_TOOL_NAME:
             raise ValueError(f'未找到工具: {name}')
+        self.ap.logger.info(
+            'sandbox_exec tool invoked: '
+            f'query_id={query.query_id} '
+            f'parameters={json.dumps(self._summarize_parameters(parameters), ensure_ascii=False)}'
+        )
         return await self.ap.box_service.execute_sandbox_tool(parameters, query)
 
     async def shutdown(self):
@@ -61,6 +68,19 @@ class NativeToolLoader(loader.ToolLoader):
                         'type': 'string',
                         'description': 'Optional sandbox session id. Defaults to the current request id for reuse.',
                     },
+                    'host_path': {
+                        'type': 'string',
+                        'description': (
+                            'Optional absolute host directory path to mount into the sandbox as /workspace. '
+                            'The path must be under an allowed host mount root.'
+                        ),
+                    },
+                    'host_path_mode': {
+                        'type': 'string',
+                        'description': 'Mount mode for host_path. Use rw to create or modify host files.',
+                        'enum': ['ro', 'rw'],
+                        'default': 'rw',
+                    },
                     'env': {
                         'type': 'object',
                         'description': 'Optional environment variables to expose inside the sandbox.',
@@ -73,3 +93,17 @@ class NativeToolLoader(loader.ToolLoader):
             },
             func=lambda parameters: parameters,
         )
+
+    def _summarize_parameters(self, parameters: dict) -> dict:
+        summary = dict(parameters)
+        cmd = str(summary.get('cmd', '')).strip()
+        if len(cmd) > 400:
+            cmd = f'{cmd[:397]}...'
+        summary['cmd'] = cmd
+
+        env = summary.get('env')
+        if isinstance(env, dict):
+            summary['env_keys'] = sorted(str(key) for key in env.keys())
+            del summary['env']
+
+        return summary