diff --git a/api/apps/sdk/files.py b/api/apps/sdk/files.py
index 14ed3bf706..4d762017e9 100644
--- a/api/apps/sdk/files.py
+++ b/api/apps/sdk/files.py
@@ -148,6 +148,62 @@ async def upload(tenant_id):
         return server_error_response(e)
 
 
+@manager.route("/file/upload_info", methods=["POST"])  # noqa: F821
+@token_required
+async def upload_info(tenant_id):
+    """
+    Upload runtime file metadata for SDK chat completions.
+    ---
+    tags:
+      - File
+    security:
+      - ApiKeyAuth: []
+    parameters:
+      - in: formData
+        name: file
+        type: file
+        required: false
+        description: File(s) to upload as runtime attachments.
+      - in: query
+        name: url
+        type: string
+        required: false
+        description: Optional URL to fetch and convert into a runtime attachment.
+    responses:
+      200:
+        description: Runtime attachment descriptor(s) for the `files` field in completions requests.
+    """
+    files = await request.files
+    file_objs = files.getlist("file") if files and files.get("file") else []
+    url = request.args.get("url")
+
+    if file_objs and url:
+        return get_json_result(
+            data=False,
+            message="Provide either multipart file(s) or ?url=..., not both.",
+            code=RetCode.BAD_REQUEST,
+        )
+
+    if not file_objs and not url:
+        return get_json_result(
+            data=False,
+            message="Missing input: provide multipart file(s) or url",
+            code=RetCode.BAD_REQUEST,
+        )
+
+    try:
+        if url and not file_objs:
+            return get_json_result(data=FileService.upload_info(tenant_id, None, url))
+
+        if len(file_objs) == 1:
+            return get_json_result(data=FileService.upload_info(tenant_id, file_objs[0], None))
+
+        results = [FileService.upload_info(tenant_id, f) for f in file_objs]
+        return get_json_result(data=results)
+    except Exception as e:
+        return server_error_response(e)
+
+
 @manager.route('/file/create', methods=['POST'])  # noqa: F821
 @token_required
 async def create(tenant_id):
diff --git a/api/db/services/conversation_service.py b/api/db/services/conversation_service.py
index 3287ac1578..0a433b6926 100644
--- a/api/db/services/conversation_service.py
+++ b/api/db/services/conversation_service.py
@@ -158,6 +158,11 @@ async def async_completion(tenant_id, chat_id, question, name="New session", ses
         "role": "user",
         "id": str(uuid4())
     }
+
+    # Propagate runtime attachments so downstream chat flow can resolve file content.
+    if isinstance(kwargs.get("files"), list) and kwargs["files"]:
+        question["files"] = kwargs["files"]
+
     conv.message.append(question)
     for m in conv.message:
         if m["role"] == "system":
diff --git a/docs/references/http_api_reference.md b/docs/references/http_api_reference.md
index 5cc930f57c..65a020ab77 100644
--- a/docs/references/http_api_reference.md
+++ b/docs/references/http_api_reference.md
@@ -6124,6 +6124,69 @@ Failure:
 
 ---
 
+### Upload document
+
+**POST** `/api/v1/file/upload_info`
+
+Uploads a file and creates the respective document
+
+#### Request
+
+- Method: POST
+- URL: `/api/v1/file/upload_info`
+- Headers:
+  - `'Content-Type: multipart/form-data`
+  - `'Authorization: Bearer <YOUR_API_KEY>'`
+- Form:
+  - `'file=@{FILE_PATH}'`
+
+##### Request example
+
+```bash
+curl --request POST \
+     --url http://{address}/api/v1/file/upload_info \
+     --header 'Content-Type: multipart/form-data' \
+     --header 'Authorization: Bearer <YOUR_API_KEY>' \
+     --form 'file=@./test1.pdf'
+```
+
+##### Request parameters
+
+- `'file'`: (*Form parameter*), `file`, *Required*  
+  The file to upload.
+
+#### Response
+
+Success:
+
+```json
+{
+    "code": 0,
+    "data": {
+      "created_at": 1772451421.7924063,
+      "created by": "be951084066611f18f5f00155d2f98f4",
+      "extension": "pdf",
+      "id": "2143a03d162c11f1b80f00155d334d02",
+      "mime_type": "application/pdf",
+      "name": "test1.pdf",
+      "preview_url": null,
+      "size": 49705
+    },
+    "message": "success"
+}
+```
+
+Failure:
+
+```json
+{
+    "code": 400,
+    "message": "Provide either multipart file(s) or ?url=...!"
+}
+```
+
+---
+
 ### Create file or folder
 
 **POST** `/api/v1/file/create`