try jsonify

openatlas/views/file.py

@@ -1,11 +1,10 @@
-import json
 import os
 import subprocess
 from pathlib import Path
 from typing import Any, Union, Optional
 
-import requests
-from flask import g, render_template, request, send_from_directory, url_for
+from flask import g, render_template, request, send_from_directory, url_for, \
+    jsonify
 from flask_babel import lazy_gettext as _
 from flask_cors import cross_origin
 from werkzeug.utils import redirect
@@ -166,7 +165,7 @@ def getManifest(id_):
 @app.route('/iiif_manifest/<int:id_>.json')
 @cross_origin()
 def iiif_manifest(id_: int):
-    return json.dumps(getManifest(id_))
+    return jsonify(getManifest(id_))
 
 
 @app.route('/iiif/<int:id_>', methods=['GET'])