From 1364df09136af2f30365a187ad4bf716435926e9 Mon Sep 17 00:00:00 2001
From: Timothy Jaeryang Baek <tim@openwebui.com>
Date: Sun, 8 Mar 2026 18:26:36 -0500
Subject: [PATCH] refac

---
 backend/open_webui/models/files.py | 10 ++++++-
 backend/open_webui/utils/misc.py   | 45 ++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/backend/open_webui/models/files.py b/backend/open_webui/models/files.py
index 59459cfb90..84dd43f5e8 100644
--- a/backend/open_webui/models/files.py
+++ b/backend/open_webui/models/files.py
@@ -4,6 +4,7 @@ from typing import Optional
 
 from sqlalchemy.orm import Session
 from open_webui.internal.db import Base, JSONField, get_db, get_db_context
+from open_webui.utils.misc import sanitize_metadata
 from pydantic import BaseModel, ConfigDict, model_validator
 from sqlalchemy import BigInteger, Column, String, Text, JSON
 
@@ -127,9 +128,16 @@ class FilesTable:
         self, user_id: str, form_data: FileForm, db: Optional[Session] = None
     ) -> Optional[FileModel]:
         with get_db_context(db) as db:
+            file_data = form_data.model_dump()
+
+            # Sanitize meta to remove non-JSON-serializable objects
+            # (e.g. callable tool functions, MCP client instances from middleware)
+            if file_data.get("meta"):
+                file_data["meta"] = sanitize_metadata(file_data["meta"])
+
             file = FileModel(
                 **{
-                    **form_data.model_dump(),
+                    **file_data,
                     "user_id": user_id,
                     "created_at": int(time.time()),
                     "updated_at": int(time.time()),
diff --git a/backend/open_webui/utils/misc.py b/backend/open_webui/utils/misc.py
index 35e19d70ce..bab1bb4bbf 100644
--- a/backend/open_webui/utils/misc.py
+++ b/backend/open_webui/utils/misc.py
@@ -566,6 +566,51 @@ def sanitize_data_for_db(obj):
     return obj
 
 
+def sanitize_metadata(metadata: dict) -> dict:
+    """
+    Return a JSON-safe copy of a metadata dict for database storage.
+
+    The middleware metadata accumulates non-serializable Python objects
+    (e.g. callable tool functions, MCP client instances) that cause
+    PostgreSQL JSON inserts to fail.  This helper strips those out while
+    preserving the primitive data needed for file-to-chat linking.
+    """
+    if not isinstance(metadata, dict):
+        return metadata
+
+    def _sanitize(obj):
+        if isinstance(obj, (str, int, float, bool, type(None))):
+            return obj
+        if isinstance(obj, dict):
+            return {
+                k: _sanitize(v)
+                for k, v in obj.items()
+                if not callable(v) and _is_serializable(v)
+            }
+        if isinstance(obj, list):
+            return [_sanitize(v) for v in obj if not callable(v) and _is_serializable(v)]
+        if callable(obj):
+            return None
+        # Last resort: try to see if it's serializable
+        try:
+            json.dumps(obj)
+            return obj
+        except (TypeError, ValueError):
+            return None
+
+    def _is_serializable(obj):
+        """Quick check whether a value can survive JSON serialization."""
+        if isinstance(obj, (str, int, float, bool, type(None), dict, list)):
+            return True
+        try:
+            json.dumps(obj)
+            return True
+        except (TypeError, ValueError):
+            return False
+
+    return _sanitize(metadata)
+
+
 def extract_folders_after_data_docs(path):
     # Convert the path to a Path object if it's not already
     path = Path(path)