multi_agent_chat/subagents: expose knowledge_base as ask_knowledge_base tool for siblings

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/index.py

@@ -16,6 +16,7 @@ def build_filesystem_mw(
     search_space_id: int,
     user_id: str | None,
     thread_id: int | None,
+    read_only: bool = False,
 ) -> SurfSenseFilesystemMiddleware:
     return SurfSenseFilesystemMiddleware(
         backend=backend_resolver,
@@ -23,4 +24,5 @@ def build_filesystem_mw(
         search_space_id=search_space_id,
         created_by_id=user_id,
         thread_id=thread_id,
+        read_only=read_only,
     )

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/middleware.py

@@ -28,6 +28,7 @@ from ..tools import (
 )
 from ..tools.glob.description import select_description as glob_description
 from ..tools.grep.description import select_description as grep_description
+from .read_only_policy import READ_ONLY_TOOL_NAMES
 
 
 class SurfSenseFilesystemMiddleware(FilesystemMiddleware):
@@ -44,12 +45,16 @@ class SurfSenseFilesystemMiddleware(FilesystemMiddleware):
         created_by_id: str | None = None,
         thread_id: int | str | None = None,
         tool_token_limit_before_evict: int | None = 20000,
+        read_only: bool = False,
     ) -> None:
         self._filesystem_mode = filesystem_mode
         self._search_space_id = search_space_id
         self._created_by_id = created_by_id
         self._thread_id = thread_id
-        self._sandbox_available = is_sandbox_enabled() and thread_id is not None
+        self._read_only = read_only
+        self._sandbox_available = (
+            is_sandbox_enabled() and thread_id is not None and not read_only
+        )
 
         system_prompt = build_system_prompt(
             filesystem_mode,
@@ -72,6 +77,9 @@ class SurfSenseFilesystemMiddleware(FilesystemMiddleware):
         if self._sandbox_available:
             self.tools.append(create_execute_code_tool(self))
 
+        if read_only:
+            self.tools = [t for t in self.tools if t.name in READ_ONLY_TOOL_NAMES]
+
     # ----------------------------------------- base-class tool overrides
 
     def _create_ls_tool(self) -> BaseTool:

surfsense_backend/app/agents/multi_agent_chat/middleware/shared/filesystem/middleware/read_only_policy.py

@@ -0,0 +1,7 @@
+"""Allowlist consulted by ``SurfSenseFilesystemMiddleware`` when ``read_only=True``."""
+
+from __future__ import annotations
+
+READ_ONLY_TOOL_NAMES = frozenset(
+    {"ls", "read_file", "glob", "grep", "list_tree", "pwd", "cd"}
+)

surfsense_backend/app/agents/multi_agent_chat/middleware/stack.py

@@ -15,6 +15,7 @@ from typing import Any
 
 from deepagents import SubAgent
 from deepagents.backends import StateBackend
+from langchain.agents import create_agent
 from langchain_core.language_models import BaseChatModel
 from langchain_core.tools import BaseTool
 from langgraph.types import Checkpointer
@@ -23,6 +24,13 @@ from app.agents.multi_agent_chat.subagents import (
     build_subagents,
     get_subagents_to_exclude,
 )
+from app.agents.multi_agent_chat.subagents.builtins.knowledge_base.agent import (
+    READONLY_NAME as KB_READONLY_NAME,
+    build_readonly_subagent as build_kb_readonly_subagent,
+)
+from app.agents.multi_agent_chat.subagents.builtins.knowledge_base.ask_knowledge_base_tool import (
+    build_ask_knowledge_base_tool,
+)
 from app.agents.multi_agent_chat.subagents.shared.permissions import ToolsPermissions
 from app.agents.new_chat.feature_flags import AgentFeatureFlags
 from app.agents.new_chat.filesystem_selection import FilesystemMode
@@ -93,14 +101,31 @@ def build_main_agent_deepagent_middleware(
         "backend_resolver": backend_resolver,
         "filesystem_mode": filesystem_mode,
     }
+    shared_subagent_middleware = build_subagent_middleware_stack(resilience=resilience)
+
+    kb_readonly_spec = build_kb_readonly_subagent(
+        dependencies=subagent_dependencies,
+        model=llm,
+        middleware_stack=shared_subagent_middleware,
+    )
+    kb_readonly_runnable = create_agent(
+        llm,
+        system_prompt=kb_readonly_spec["system_prompt"],
+        tools=kb_readonly_spec["tools"],
+        middleware=kb_readonly_spec["middleware"],
+        name=KB_READONLY_NAME,
+        checkpointer=checkpointer,
+    )
+    ask_kb_tool = build_ask_knowledge_base_tool(kb_readonly_runnable)
 
     subagents: list[SubAgent] = build_subagents(
         dependencies=subagent_dependencies,
         model=llm,
-        middleware_stack=build_subagent_middleware_stack(resilience=resilience),
+        middleware_stack=shared_subagent_middleware,
         mcp_tools_by_agent=mcp_tools_by_agent or {},
         exclude=get_subagents_to_exclude(available_connectors),
         disabled_tools=disabled_tools,
+        ask_kb_tool=ask_kb_tool,
     )
     logging.debug("Subagents registry: %s", [s["name"] for s in subagents])