diff --git a/libretranslate/api_keys.py b/libretranslate/api_keys.py
index 0583531..ea9e603 100644
--- a/libretranslate/api_keys.py
+++ b/libretranslate/api_keys.py
@@ -87,7 +87,7 @@ class RemoteDatabase:
         req_limit = self.cache.get(api_key)
         if req_limit is None:
             try:
-                r = requests.post(self.url, data={'api_key': api_key})
+                r = requests.post(self.url, data={'api_key': api_key}, timeout=60)
                 res = r.json()
             except Exception as e:
                 print("Cannot authenticate API key: " + str(e))
diff --git a/libretranslate/app.py b/libretranslate/app.py
index 77197f2..39ad1ec 100644
--- a/libretranslate/app.py
+++ b/libretranslate/app.py
@@ -129,8 +129,8 @@ def create_app(args):
 
     from libretranslate.language import load_languages
 
-    SWAGGER_URL = args.url_prefix + "/docs"  # Swagger UI (w/o trailing '/')
-    API_URL = args.url_prefix + "/spec"
+    swagger_url = args.url_prefix + "/docs"  # Swagger UI (w/o trailing '/')
+    api_url = args.url_prefix + "/spec"
 
     bp = Blueprint('Main app', __name__)
 
@@ -339,7 +339,7 @@ def create_app(args):
             get_api_key_link=args.get_api_key_link,
             web_version=os.environ.get("LT_WEB") is not None,
             version=get_version(),
-            swagger_url=SWAGGER_URL,
+            swagger_url=swagger_url,
             available_locales=[{'code': l['code'], 'name': _lazy(l['name'])} for l in get_available_locales(not args.debug)],
             current_locale=get_locale(),
             alternate_locales=get_alternate_locale_links()
@@ -792,7 +792,7 @@ def create_app(args):
             checked_filepath = security.path_traversal_check(filepath, get_upload_dir())
             if os.path.isfile(checked_filepath):
                 filepath = checked_filepath
-        except security.SuspiciousFileOperation:
+        except security.SuspiciousFileOperationError:
             abort(400, description=_("Invalid filename"))
 
         return_data = io.BytesIO()
@@ -1075,7 +1075,7 @@ def create_app(args):
     swag["info"]["version"] = get_version()
     swag["info"]["title"] = "LibreTranslate"
 
-    @app.route(API_URL)
+    @app.route(api_url)
     @limiter.exempt
     def spec():
         return jsonify(lazy_swag(swag))
@@ -1093,9 +1093,9 @@ def create_app(args):
     app.jinja_env.globals.update(_e=gettext_escaped, _h=gettext_html)
 
     # Call factory function to create our blueprint
-    swaggerui_blueprint = get_swaggerui_blueprint(SWAGGER_URL, API_URL)
+    swaggerui_blueprint = get_swaggerui_blueprint(swagger_url, api_url)
     if args.url_prefix:
-        app.register_blueprint(swaggerui_blueprint, url_prefix=SWAGGER_URL)
+        app.register_blueprint(swaggerui_blueprint, url_prefix=swagger_url)
     else:
         app.register_blueprint(swaggerui_blueprint)
 
diff --git a/libretranslate/detect.py b/libretranslate/detect.py
index 8717658..b9f6f2e 100644
--- a/libretranslate/detect.py
+++ b/libretranslate/detect.py
@@ -3,7 +3,7 @@
 import pycld2 as cld2
 
 
-class UnknownLanguage(Exception):
+class UnknownLanguageError(Exception):
   pass
 
 class Language:
@@ -57,9 +57,9 @@ class Detector:
     if not reliable:
       self.reliable = False
       reliable, index, top_3_choices = cld2.detect(text, bestEffort=True)
-      
+
       if not self.quiet and not reliable:
-        raise UnknownLanguage("Try passing a longer snippet of text")
+        raise UnknownLanguageError("Try passing a longer snippet of text")
 
     self.languages = [Language(x) for x in top_3_choices]
     self.language = self.languages[0]
@@ -69,4 +69,4 @@ class Detector:
     text = f"Prediction is reliable: {self.reliable}\n"
     text += "\n".join([f"Language {i+1}: {str(l)}"
                         for i,l in enumerate(self.languages)])
-    return text
\ No newline at end of file
+    return text
diff --git a/libretranslate/language.py b/libretranslate/language.py
index 68e3e48..75fd0a7 100644
--- a/libretranslate/language.py
+++ b/libretranslate/language.py
@@ -1,7 +1,7 @@
 
 from argostranslate import translate
 
-from libretranslate.detect import Detector, UnknownLanguage
+from libretranslate.detect import Detector, UnknownLanguageError
 
 __languages = None
 
@@ -29,7 +29,7 @@ def detect_languages(text):
             for i in range(len(d)):
                 d[i].text_length = len(t)
             candidates.extend(d)
-        except UnknownLanguage:
+        except UnknownLanguageError:
             pass
 
     # total read bytes of the provided text
@@ -83,10 +83,10 @@ def improve_translation_formatting(source, translation, improve_punctuation=True
 
     if not len(source):
         return ""
-    
+
     if not len(translation):
         return source
-    
+
     if improve_punctuation:
         source_last_char = source[len(source) - 1]
         translation_last_char = translation[len(translation) - 1]
diff --git a/libretranslate/security.py b/libretranslate/security.py
index 3c4023a..7163a83 100644
--- a/libretranslate/security.py
+++ b/libretranslate/security.py
@@ -1,7 +1,7 @@
 import os
 
 
-class SuspiciousFileOperation(Exception):
+class SuspiciousFileOperationError(Exception):
     pass
 
 
@@ -10,7 +10,7 @@ def path_traversal_check(unsafe_path, known_safe_path):
     unsafe_path = os.path.abspath(unsafe_path)
 
     if (os.path.commonprefix([known_safe_path, unsafe_path]) != known_safe_path):
-        raise SuspiciousFileOperation(f"{unsafe_path} is not safe")
+        raise SuspiciousFileOperationError(f"{unsafe_path} is not safe")
 
     # Passes the check
-    return unsafe_path
\ No newline at end of file
+    return unsafe_path
diff --git a/pyproject.toml b/pyproject.toml
index e9eaed8..17b9fb1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,6 +20,7 @@ keywords = [
     "Python",
     "Translate",
     "Translation",
+    "API",
 ]
 classifiers = [
     "Operating System :: OS Independent",
@@ -64,9 +65,8 @@ ltmanage = "libretranslate.manage:manage"
 test = [
     "pytest >=7.2.0",
     "pytest-cov",
-    "flake8",
+    "ruff ==0.0.277",
     "types-requests",
-    # "mypy >=1.4.1",
 ]
 
 
@@ -86,16 +86,11 @@ features = [
 
 [tool.hatch.envs.default.scripts]
 dev = "python main.py {args}"
-lint = [
-    # "flake8 . --count --exit-zero --select=E9,F63,F7,F82 --show-source --statistics",
-    # "flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics",
-    "ruff libretranslate scripts",
-]
 fmt = [
     "ruff libretranslate scripts --fix",
 ]
 test = [
-    # "fmt",
+    "fmt",
     "pytest {args}",
 ]
 cov = [
@@ -124,7 +119,7 @@ addopts = [
 ]
 
 
-# https://github.com/charliermarsh/ruff#supported-rules
+# https://beta.ruff.rs/docs/rules
 [tool.ruff]
 src = ["libretranslate", "scripts"]
 target-version = "py38"
@@ -155,8 +150,6 @@ select = [
 ]
 
 ignore = [
-    # "E741", # From original flake8 ignore
-    # "B008", # do not perform function calls in argument defaults (required for FastAPI afaik)
     "E501", # line too long
     "A003", # Class attribute is shadowing a python builtin
     "S101", # Use of `assert` detected
diff --git a/scripts/healthcheck.py b/scripts/healthcheck.py
index 20eba19..07bcaa4 100644
--- a/scripts/healthcheck.py
+++ b/scripts/healthcheck.py
@@ -7,6 +7,7 @@ response = requests.post(
          'q': 'Hello World!',
          'source': 'en',
          'target': 'en'
-    }
+    },
+    timeout=60
 )
 # if server unavailable then requests with raise exception and healthcheck will fail