diff --git a/tests/tools/test_ckg_tool.py b/tests/tools/test_ckg_tool.py
new file mode 100644
index 000000000..2e0546c8d
--- /dev/null
+++ b/tests/tools/test_ckg_tool.py
@@ -0,0 +1,73 @@
+# Copyright (c) 2025 ByteDance Ltd. and/or its affiliates
+# SPDX-License-Identifier: MIT
+
+import unittest
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest.mock import MagicMock, patch
+
+from trae_agent.tools.base import ToolCallArguments
+from trae_agent.tools.ckg_tool import CKGTool
+
+
+class TestCKGTool(unittest.IsolatedAsyncioTestCase):
+    async def test_execute_accepts_file_path_inside_codebase(self):
+        with TemporaryDirectory() as tmpdir:
+            code_file = Path(tmpdir) / "example.py"
+            code_file.write_text("def target():\n    return 1\n")
+
+            ckg_database = MagicMock()
+            ckg_database.query_function.return_value = []
+
+            with patch(
+                "trae_agent.tools.ckg_tool.CKGDatabase", return_value=ckg_database
+            ) as ckg_database_cls:
+                result = await CKGTool().execute(
+                    ToolCallArguments(
+                        {
+                            "command": "search_function",
+                            "path": str(code_file),
+                            "identifier": "target",
+                            "print_body": False,
+                        }
+                    )
+                )
+
+            self.assertIsNone(result.error)
+            self.assertEqual(result.output, "No functions named target found.")
+            ckg_database_cls.assert_called_once_with(code_file.parent)
+
+    async def test_execute_uses_git_root_for_file_path(self):
+        with TemporaryDirectory() as tmpdir:
+            codebase_root = Path(tmpdir)
+            nested_dir = codebase_root / "pkg"
+            nested_dir.mkdir()
+            code_file = nested_dir / "example.py"
+            code_file.write_text("def target():\n    return 1\n")
+
+            ckg_database = MagicMock()
+            ckg_database.query_function.return_value = []
+            git_result = MagicMock(returncode=0, stdout=f"{codebase_root}\n")
+
+            with (
+                patch("trae_agent.tools.ckg_tool.subprocess.run", return_value=git_result),
+                patch(
+                    "trae_agent.tools.ckg_tool.CKGDatabase", return_value=ckg_database
+                ) as ckg_database_cls,
+            ):
+                result = await CKGTool().execute(
+                    ToolCallArguments(
+                        {
+                            "command": "search_function",
+                            "path": str(code_file),
+                            "identifier": "target",
+                        }
+                    )
+                )
+
+            self.assertIsNone(result.error)
+            ckg_database_cls.assert_called_once_with(codebase_root)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/trae_agent/tools/ckg_tool.py b/trae_agent/tools/ckg_tool.py
index 49da80ddc..17a15fe67 100644
--- a/trae_agent/tools/ckg_tool.py
+++ b/trae_agent/tools/ckg_tool.py
@@ -1,6 +1,7 @@
 # Copyright (c) 2025 ByteDance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
+import subprocess
 from pathlib import Path
 from typing import override
 
@@ -60,7 +61,7 @@ def get_parameters(self) -> list[ToolParameter]:
             ToolParameter(
                 name="path",
                 type="string",
-                description="The path to the codebase.",
+                description="The path to the codebase root or to a file inside the codebase.",
                 required=True,
             ),
             ToolParameter(
@@ -105,7 +106,9 @@ async def execute(self, arguments: ToolCallArguments) -> ToolExecResult:
                 error=f"Codebase path {path} does not exist",
                 error_code=-1,
             )
-        if not codebase_path.is_dir():
+        if codebase_path.is_file():
+            codebase_path = self._resolve_codebase_path_from_file(codebase_path)
+        elif not codebase_path.is_dir():
             return ToolExecResult(
                 error=f"Codebase path {path} is not a directory",
                 error_code=-1,
@@ -132,6 +135,23 @@ async def execute(self, arguments: ToolCallArguments) -> ToolExecResult:
             case _:
                 return ToolExecResult(error=f"Invalid command: {command}", error_code=-1)
 
+    def _resolve_codebase_path_from_file(self, file_path: Path) -> Path:
+        parent = file_path.parent
+        try:
+            result = subprocess.run(
+                ["git", "rev-parse", "--show-toplevel"],
+                cwd=parent,
+                capture_output=True,
+                text=True,
+                timeout=5,
+                check=False,
+            )
+            if result.returncode == 0 and result.stdout.strip():
+                return Path(result.stdout.strip())
+        except (FileNotFoundError, subprocess.TimeoutExpired):
+            pass
+        return parent
+
     def _search_function(
         self, ckg_database: CKGDatabase, identifier: str, print_body: bool = True
     ) -> str: