diff --git a/site/api.py b/site/api.py
index 7096d2a..01c6b02 100644
--- a/site/api.py
+++ b/site/api.py
@@ -18,6 +18,7 @@ import parser as parser_mod
 import textify
 import extractor
 import differ
+import mimeutil
 
 api_bp = Blueprint("api", __name__)
 
@@ -107,7 +108,7 @@ def add_supplement(contract_id):
         return jsonify({"error": "empty filename"}), 400
 
     filename = file.filename
-    mime_type = _guess_mime(filename) or file.content_type or "application/octet-stream"
+    mime_type = mimeutil.guess_mime(filename) or file.content_type or "application/octet-stream"
     file_bytes = file.read()
 
     # 2. Сохранить в documents
@@ -260,18 +261,3 @@ def get_history(contract_id):
 
 # ── Вспомогательные ─────────────────────────────────────────────
 
-def _guess_mime(filename: str) -> str:
-    """MIME-тип по расширению."""
-    ext = filename.lower().rsplit(".", 1)[-1] if "." in filename else ""
-    return {
-        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
-        "doc": "application/msword",
-        "pdf": "application/pdf",
-        "zip": "application/zip",
-    }.get(ext, "")
-
-
-def _jsonb(val):
-    """Подготовить значение для JSONB-колонки."""
-    import json
-    return json.dumps(val, ensure_ascii=False, default=str) if val is not None else None
diff --git a/site/mimeutil.py b/site/mimeutil.py
new file mode 100644
index 0000000..0eb72c1
--- /dev/null
+++ b/site/mimeutil.py
@@ -0,0 +1,12 @@
+"""Общий MIME-утилит для всего проекта."""
+
+
+def guess_mime(filename: str) -> str:
+    """Определить MIME-тип по расширению файла."""
+    ext = filename.lower().rsplit(".", 1)[-1] if "." in filename else ""
+    return {
+        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        "doc": "application/msword",
+        "pdf": "application/pdf",
+        "zip": "application/zip",
+    }.get(ext, "application/octet-stream")
diff --git a/site/upload.py b/site/upload.py
index 660f7dc..9d3e3a9 100644
--- a/site/upload.py
+++ b/site/upload.py
@@ -18,6 +18,7 @@ from flask import Blueprint, request, jsonify
 import db
 import parser
 import textify
+import mimeutil
 
 upload_bp = Blueprint("upload", __name__)
 
@@ -40,7 +41,7 @@ def upload():
 
     # 2. Определить MIME-тип (приоритет: расширение, а не content_type от браузера)
     filename = file.filename
-    mime_type = _guess_mime(filename) or file.content_type or "application/octet-stream"
+    mime_type = mimeutil.guess_mime(filename) or file.content_type or "application/octet-stream"
     file_bytes = file.read()
 
     if not file_bytes:
@@ -101,16 +102,3 @@ def upload():
     })
 
 
-def _guess_mime(filename: str) -> str:
-    """
-    Угадать MIME-тип по расширению файла.
-    Используется когда браузер не передал content_type.
-    """
-    ext = filename.lower().rsplit(".", 1)[-1] if "." in filename else ""
-    mime_map = {
-        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
-        "doc":  "application/msword",
-        "pdf":  "application/pdf",
-        "zip":  "application/zip",
-    }
-    return mime_map.get(ext, "application/octet-stream")