From 1517e8675d5c876eb92b13bafaae3e4c71f55d08 Mon Sep 17 00:00:00 2001
From: Henry Li <henry1943@163.com>
Date: Fri, 16 Jan 2026 21:48:00 +0800
Subject: [PATCH] feat: add present_file tool

---
 backend/src/tools/builtins/__init__.py        |  3 +++
 .../src/tools/builtins/present_file_tool.py   | 24 +++++++++++++++++++
 backend/src/tools/tools.py                    |  8 ++++++-
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 backend/src/tools/builtins/__init__.py
 create mode 100644 backend/src/tools/builtins/present_file_tool.py

diff --git a/backend/src/tools/builtins/__init__.py b/backend/src/tools/builtins/__init__.py
new file mode 100644
index 0000000..5c87b04
--- /dev/null
+++ b/backend/src/tools/builtins/__init__.py
@@ -0,0 +1,3 @@
+from .present_file_tool import present_file_tool
+
+__all__ = ["present_file_tool"]
diff --git a/backend/src/tools/builtins/present_file_tool.py b/backend/src/tools/builtins/present_file_tool.py
new file mode 100644
index 0000000..bc1fef2
--- /dev/null
+++ b/backend/src/tools/builtins/present_file_tool.py
@@ -0,0 +1,24 @@
+from langchain.tools import tool
+
+
+@tool("present_files", parse_docstring=True)
+def present_file_tool(filepaths: list[str]) -> str:
+    """Make files visible to the user for viewing and rendering in the client interface.
+
+    When to use the present_files tool:
+
+    - Making any file available for the user to view, download, or interact with
+    - Presenting multiple related files at once
+    - After creating a file that should be presented to the user
+
+    When NOT to use the present_files tool:
+    - When you only need to read file contents for your own processing
+    - For temporary or intermediate files not meant for user viewing
+
+    Args:
+        filepaths: List of absolute file paths to present to the user. **Only** files in `/mnt/user-data/outputs` can be presented.
+
+    Returns:
+        "OK" if the files were presented successfully.
+    """
+    return "OK"
diff --git a/backend/src/tools/tools.py b/backend/src/tools/tools.py
index 870df6b..a89a4b1 100644
--- a/backend/src/tools/tools.py
+++ b/backend/src/tools/tools.py
@@ -2,9 +2,15 @@ from langchain.tools import BaseTool
 
 from src.config import get_app_config
 from src.reflection import resolve_variable
+from src.tools.builtins import present_file_tool
+
+BUILTIN_TOOLS = [
+    present_file_tool,
+]
 
 
 def get_available_tools(groups: list[str] | None = None) -> list[BaseTool]:
     """Get all available tools from config"""
     config = get_app_config()
-    return [resolve_variable(tool.use, BaseTool) for tool in config.tools if groups is None or tool.group in groups]
+    loaded_tools = [resolve_variable(tool.use, BaseTool) for tool in config.tools if groups is None or tool.group in groups]
+    return loaded_tools + BUILTIN_TOOLS