diff --git a/.ruff.toml b/.ruff.toml
new file mode 100644
index 0000000..cc72b19
--- /dev/null
+++ b/.ruff.toml
@@ -0,0 +1,4 @@
+select = ["ALL"]
+ignore = ["ANN101", "ANN102", "D203", "D211", "D212", "D213", "UP009", "S101", "S314", "INP001", "FLY002", "TD002", "TD003"]
+
+exclude = ["docs"]
diff --git a/MANIFEST.in b/MANIFEST.in
index 6fd9ca2..0baab13 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,19 +1,11 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
-# TODO: Generate this manifest file by running the following commands:
-# (please sort the lines in this file after running below commands)
-#
-#  git init
-#  git add -A
-#  pip install -e .[all]
-#  check-manifest -u
-
 include .dockerignore
 include .editorconfig
 include .tx/config
@@ -26,6 +18,7 @@ include *.md
 include *.rst
 include *.sh
 include *.txt
+include *.toml
 include babel.ini
 include pytest.ini
 recursive-include docs *.bat
diff --git a/docs/conf.py b/docs/conf.py
index 5b87394..89fbd91 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -29,6 +29,10 @@
     "sphinx.ext.viewcode",
 ]
 
+nitpick_ignore = [
+    ("py:class", "flask.app.Flask"),
+]
+
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]
 
diff --git a/invenio_campusonline/__init__.py b/invenio_campusonline/__init__.py
index 788d80b..15c523e 100644
--- a/invenio_campusonline/__init__.py
+++ b/invenio_campusonline/__init__.py
@@ -1,12 +1,12 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
-"""This module is used to import/export from/to the CampusOnline System."""
+"""The module is used to import/export from/to the CampusOnline System."""
 
 from .api import fetch_all_ids, import_from_campusonline
 from .ext import InvenioCampusonline
diff --git a/invenio_campusonline/api.py b/invenio_campusonline/api.py
index 35c4bd5..ab1ad78 100644
--- a/invenio_campusonline/api.py
+++ b/invenio_campusonline/api.py
@@ -7,9 +7,10 @@
 # file for more details.
 
 """API functions of the campusonline connector."""
-from typing import Callable
+from collections.abc import Callable
 from xml.etree.ElementTree import fromstring
 
+from invenio_records_resources.services.records.results import RecordItem
 from requests import post
 
 from .types import (
@@ -29,14 +30,18 @@
 
 
 def import_from_campusonline(
-    import_func: Callable, cms_id: CampusOnlineID, configs: CampusOnlineConfigs
-):
+    import_func: Callable,
+    cms_id: CampusOnlineID,
+    configs: CampusOnlineConfigs,
+) -> RecordItem:
     """Import record from campusonline."""
     return import_func(cms_id, configs, get_metadata, download_file)
 
 
 def fetch_all_ids(
-    endpoint: URL, token: CampusOnlineToken, theses_filters: ThesesFilter = None
+    endpoint: URL,
+    token: CampusOnlineToken,
+    theses_filters: ThesesFilter = None,
 ) -> list[tuple[CampusOnlineID, ThesesState]]:
     """Fetch to import ids."""
     ids = []
@@ -44,7 +49,7 @@ def fetch_all_ids(
         body = create_request_body_ids(token, theses_filter)
 
         headers = create_request_header("getAllThesesMetadataRequest")
-        response = post(endpoint, data=body, headers=headers)
+        response = post(endpoint, data=body, headers=headers, timeout=10)
 
         root = fromstring(response.text)
         xpath = "{http://www.campusonline.at/thesisservice/basetypes}ID"
diff --git a/invenio_campusonline/cli.py b/invenio_campusonline/cli.py
index 3317f75..aed3207 100644
--- a/invenio_campusonline/cli.py
+++ b/invenio_campusonline/cli.py
@@ -18,7 +18,7 @@
 
 
 @group()
-def campusonline():
+def campusonline() -> None:
     """Campusonline CLI."""
 
 
@@ -28,8 +28,14 @@ def campusonline():
 @option("--campusonline-id", type=STRING)
 @option("--token", type=STRING)
 @option("--user-email", type=STRING, default="cms@tugraz.at")
-@option("--no-color", is_flag=True)
-def import_thesis(endpoint, campusonline_id, token, user_email, no_color=False):
+@option("--no-color", is_flag=True, default=False)
+def import_thesis(
+    endpoint: str,
+    campusonline_id: str,
+    token: str,
+    user_email: str,
+    no_color: bool,  # noqa: FBT001
+) -> None:
     """Import metadata and file (aka one thesis) from campusonline."""
     import_func = current_app.config["CAMPUSONLINE_IMPORT_FUNC"]
     theses_filters = current_app.config["CAMPUSONLINE_THESES_FILTERS"]
@@ -37,7 +43,12 @@ def import_thesis(endpoint, campusonline_id, token, user_email, no_color=False):
     sender = current_app.config["CAMPUSONLINE_ERROR_MAIL_SENDER"]
 
     configs = CampusOnlineConfigs(
-        endpoint, token, user_email, theses_filters, recipients, sender
+        endpoint,
+        token,
+        user_email,
+        theses_filters,
+        recipients,
+        sender,
     )
     record = import_from_campusonline(import_func, campusonline_id, configs)
 
@@ -50,7 +61,11 @@ def import_thesis(endpoint, campusonline_id, token, user_email, no_color=False):
 @option("--endpoint", type=URL)
 @option("--token", type=STRING)
 @option("--no-color", is_flag=True)
-def fetch_ids(endpoint, token, no_color):
+def fetch_ids(
+    endpoint: str,
+    token: str,
+    no_color: bool,  # noqa: FBT001
+) -> None:
     """Fetch all to import ids."""
     theses_filters = current_app.config["CAMPUSONLINE_THESES_FILTERS"]
     ids = fetch_all_ids(endpoint, token, theses_filters)
diff --git a/invenio_campusonline/config.py b/invenio_campusonline/config.py
index 675ac96..829838a 100644
--- a/invenio_campusonline/config.py
+++ b/invenio_campusonline/config.py
@@ -1,12 +1,12 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
-"""This is the configuration file."""
+"""The configuration file."""
 
 CAMPUSONLINE_ENDPOINT = ""
 """This is the endpoint to fetch the records."""
diff --git a/invenio_campusonline/ext.py b/invenio_campusonline/ext.py
index f19da53..47f4083 100644
--- a/invenio_campusonline/ext.py
+++ b/invenio_campusonline/ext.py
@@ -1,22 +1,24 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
-"""This module is used to import/export from/to the CampusOnline System."""
+"""The module is used to import/export from/to the CampusOnline System."""
+
+from flask import Flask
 
 
 class InvenioCampusonline:
     """invenio-campusonline extension."""
 
-    def __init__(self, app=None):
+    def __init__(self, app: Flask = None) -> None:
         """Extension initialization."""
         if app:
             self.init_app(app)
 
-    def init_app(self, app):
+    def init_app(self, app: Flask) -> None:
         """Flask application initialization."""
         app.extensions["invenio-campusonline"] = self
diff --git a/invenio_campusonline/tasks.py b/invenio_campusonline/tasks.py
index ae3afd9..f10c197 100644
--- a/invenio_campusonline/tasks.py
+++ b/invenio_campusonline/tasks.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2022 Graz University of Technology.
+# Copyright (C) 2022-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it
 # and/or modify it under the terms of the MIT License; see LICENSE
@@ -8,7 +8,7 @@
 
 
 """Celery tasks for `invenio-campusonline`."""
-from typing import Callable
+from collections.abc import Callable
 
 from celery import shared_task
 from flask import current_app
@@ -19,7 +19,7 @@
 
 
 def config_variables() -> tuple[Callable, CampusOnlineConfigs]:
-    """Configuration variables."""
+    """Configure variables."""
     import_func = current_app.config["CAMPUSONLINE_IMPORT_FUNC"]
     endpoint = current_app.config["CAMPUSONLINE_ENDPOINT"]
     token = current_app.config["CAMPUSONLINE_TOKEN"]
@@ -29,7 +29,12 @@ def config_variables() -> tuple[Callable, CampusOnlineConfigs]:
     sender = current_app.config["CAMPUSONLINE_ERROR_MAIL_SENDER"]
 
     return import_func, CampusOnlineConfigs(
-        endpoint, token, user_email, theses_filters, recipients, sender
+        endpoint,
+        token,
+        user_email,
+        theses_filters,
+        recipients,
+        sender,
     )
 
 
@@ -39,7 +44,7 @@ def import_theses_from_campusonline() -> None:
     import_func, configs = config_variables()
     ids = fetch_all_ids(configs.endpoint, configs.token, configs.theses_filters)
 
-    for cms_id, state in ids:
+    for cms_id, _ in ids:
         try:
             import_from_campusonline(import_func, cms_id, configs)
         except RuntimeError:
diff --git a/invenio_campusonline/types.py b/invenio_campusonline/types.py
index 617a678..0f27b08 100644
--- a/invenio_campusonline/types.py
+++ b/invenio_campusonline/types.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2022 Graz University of Technology.
+# Copyright (C) 2022-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it
 # and/or modify it under the terms of the MIT License; see LICENSE
@@ -40,14 +40,14 @@
 
 @dataclass(frozen=True)
 class Color:
-    """This class is for the output color management."""
+    """The class is for the output color management."""
 
     neutral = "black"
     error = "red"
     warning = "yellow"
     abort = "magenta"
     success = "green"
-    alternate = ["blue", "cyan"]
+    alternate = ("blue", "cyan")
 
 
 class ThesesState(Enum):
@@ -64,8 +64,8 @@ class ThesesFilter:
     filter_: list[Element]
     state: ThesesState
 
-    def __iter__(self):
-        """This method makes the properties iterable."""
+    def __iter__(self):  # noqa: ANN204
+        """Make the class iteratable."""
         return iter(astuple(self))
 
 
diff --git a/invenio_campusonline/utils.py b/invenio_campusonline/utils.py
index e6a33ee..1321066 100644
--- a/invenio_campusonline/utils.py
+++ b/invenio_campusonline/utils.py
@@ -1,12 +1,13 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2022 Graz University of Technology.
+# Copyright (C) 2022-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it
 # and/or modify it under the terms of the MIT License; see LICENSE
 # file for more details.
 
 """Command line interface to interact with the CampusOnline-Connector module."""
+from pathlib import Path
 from shutil import copyfileobj
 from xml.etree.ElementTree import Element, fromstring
 
@@ -16,7 +17,8 @@
 
 
 def create_request_body_metadata(
-    token: CampusOnlineToken, campusonline_id: CampusOnlineID
+    token: CampusOnlineToken,
+    campusonline_id: CampusOnlineID,
 ) -> str:
     """Build Request."""
     body = """
@@ -49,7 +51,8 @@ def create_request_body_metadata(
 
 
 def create_request_body_download(
-    token: CampusOnlineToken, campusonline_id: CampusOnlineID
+    token: CampusOnlineToken,
+    campusonline_id: CampusOnlineID,
 ) -> str:
     """Build Request."""
     body = """
@@ -70,7 +73,8 @@ def create_request_body_download(
 
 
 def create_request_body_ids(
-    token: CampusOnlineToken, theses_filter: list[Element]
+    token: CampusOnlineToken,
+    theses_filter: list[Element],
 ) -> str:
     """Build request."""
     body = """
@@ -91,35 +95,37 @@ def create_request_body_ids(
 
 def create_request_header(service: str) -> dict:
     """Create request header."""
-    header = {
+    return {
         "Content-Type": "application/xml",
         "SOAPAction": f"urn:service#{service}",
     }
-    return header
 
 
 def get_metadata(
-    endpoint: URL, token: CampusOnlineToken, campusonline_id: CampusOnlineID
+    endpoint: URL,
+    token: CampusOnlineToken,
+    campusonline_id: CampusOnlineID,
 ) -> Element:
     """Get Metadata."""
     body = create_request_body_metadata(token, campusonline_id)
     headers = create_request_header("getMetadataByThesisID")
-    response = post(endpoint, data=body, headers=headers)
+    response = post(endpoint, data=body, headers=headers, timeout=10)
 
     root = fromstring(response.text)
 
     xpath = "{http://www.campusonline.at/thesisservice/basetypes}thesis"
-    thesis = list(root.iter(xpath))[0]  # TODO: fix it
-    return thesis
+    return list(root.iter(xpath))[0]  # TODO: fix it
 
 
 def get_file_url(
-    endpoint: URL, token: CampusOnlineToken, campusonline_id: CampusOnlineID
+    endpoint: URL,
+    token: CampusOnlineToken,
+    campusonline_id: CampusOnlineID,
 ) -> str:
     """Get file URL."""
     body = create_request_body_download(token, campusonline_id)
     headers = create_request_header("getDocumentByThesisID")
-    response = post(endpoint, data=body, headers=headers)
+    response = post(endpoint, data=body, headers=headers, timeout=10)
 
     root = fromstring(response.text)
     xpath = "{http://www.campusonline.at/thesisservice/basetypes}docUrl"
@@ -127,19 +133,21 @@ def get_file_url(
     return file_url.text
 
 
-def store_file_temporarily(file_url: URL, file_path: FilePath):
-    """This function stores files referenced by an url to the local file path."""
-    with get(file_url, stream=True) as response:
-        with open(file_path, "wb") as fp:
+def store_file_temporarily(file_url: URL, file_path: FilePath) -> None:
+    """Store the file referenced by url to the local file path."""
+    with get(file_url, stream=True, timeout=10) as response:  # noqa: SIM117
+        with Path(file_path).open("wb") as fp:
             copyfileobj(response.raw, fp)
 
 
 def download_file(
-    endpoint: URL, token: CampusOnlineToken, campusonline_id: CampusOnlineID
+    endpoint: URL,
+    token: CampusOnlineToken,
+    campusonline_id: CampusOnlineID,
 ) -> FilePath:
-    """This function downloads files from campus online."""
+    """Download files from campus online by campusonline_id."""
     file_url = get_file_url(endpoint, token, campusonline_id)
     file_url = f"{file_url}{token}"
-    file_path = f"/tmp/{campusonline_id}.pdf"
+    file_path = f"/tmp/{campusonline_id}.pdf"  # noqa: S108
     store_file_temporarily(file_url, file_path)
     return file_path
diff --git a/run-tests.sh b/run-tests.sh
index cde5658..d9551db 100755
--- a/run-tests.sh
+++ b/run-tests.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -13,6 +13,8 @@ set -o errexit
 # Quit on unbound symbols
 set -o nounset
 
+ruff .
+
 python -m check_manifest
 python -m sphinx.cmd.build -qnNW docs docs/_build/html
 python -m pytest -s
diff --git a/setup.cfg b/setup.cfg
index 1aafba2..f6b893f 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -9,7 +9,7 @@
 [metadata]
 name = invenio-campusonline
 version = attr: invenio_campusonline.__version__
-description = "This module is used to import/export from/to the CampusOnline System."
+description = "The module is used to import/export from/to the CampusOnline System."
 long_description = file: README.rst, CHANGES.rst
 keywords = invenio TODO
 license = MIT
@@ -31,7 +31,6 @@ zip_safe = False
 install_requires =
     click>=8.0.0
     click-params>=0.4.0
-    invenio-i18n>=1.2.0
     invenio-celery>=1.2.5
     invenio-mail>=1.0.2
     requests>=2.0.0
@@ -40,7 +39,9 @@ install_requires =
 tests =
     pytest-black>=0.3.0
     pytest-invenio>=1.4.0
+    invenio-records-resources>=1.0.0
     invenio-search[opensearch2]>=2.1.0
+    ruff>=0.0.263
     sphinx>=4.5
 
 [options.entry_points]
@@ -70,5 +71,5 @@ ignore =
     *-requirements.txt
 
 [tool:pytest]
-addopts = --black --isort --pydocstyle --doctest-glob="*.rst" --doctest-modules --cov=invenio_campusonline --cov-report=term-missing
+addopts = --black --doctest-glob="*.rst" --doctest-modules --cov=invenio_campusonline --cov-report=term-missing
 testpaths = docs tests invenio_campusonline
diff --git a/setup.py b/setup.py
index ed6057f..d093acf 100644
--- a/setup.py
+++ b/setup.py
@@ -1,12 +1,12 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021-2022 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
-"""This module is used to import/export from/to the CampusOnline System."""
+"""The module is used to import/export from/to the CampusOnline System."""
 
 from setuptools import setup
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 3d21116..c01720b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -12,33 +12,20 @@
 fixtures are available.
 """
 
-import shutil
-import tempfile
 
 import pytest
 from flask import Flask
-from flask_babelex import Babel
 
 from invenio_campusonline import InvenioCampusonline
 
 
 @pytest.fixture(scope="module")
-def celery_config():
-    """Override pytest-invenio fixture.
-
-    TODO: Remove this fixture if you add Celery support.
-    """
-    return {}
-
-
-@pytest.fixture(scope="module")
-def create_app(instance_path):
+def create_app(instance_path: str) -> Flask:
     """Application factory fixture."""
 
-    def factory(**config):
+    def factory(**config: dict) -> Flask:
         app = Flask("testapp", instance_path=instance_path)
         app.config.update(**config)
-        Babel(app)
         InvenioCampusonline(app)
         return app
 
diff --git a/tests/test_invenio_campusonline.py b/tests/test_invenio_campusonline.py
index 45356e1..a05b06b 100644
--- a/tests/test_invenio_campusonline.py
+++ b/tests/test_invenio_campusonline.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2021 Graz University of Technology.
+# Copyright (C) 2021-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -10,17 +10,15 @@
 
 from flask import Flask
 
-from invenio_campusonline import InvenioCampusonline
+from invenio_campusonline import InvenioCampusonline, __version__
 
 
-def test_version():
+def test_version() -> None:
     """Test version import."""
-    from invenio_campusonline import __version__
-
     assert __version__
 
 
-def test_init():
+def test_init() -> None:
     """Test extension initialization."""
     app = Flask("testapp")
     ext = InvenioCampusonline(app)
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 5758ea3..ded8cf5 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2022 Graz University of Technology.
+# Copyright (C) 2022-2023 Graz University of Technology.
 #
 # invenio-campusonline is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -16,7 +16,7 @@
 )
 
 
-def test_create_request_body_metadata():
+def test_create_request_body_metadata() -> None:
     """Test the create_request_body_metadata function."""
     body = create_request_body_metadata("abcd", "efgh")
     expected = """
@@ -48,7 +48,7 @@ def test_create_request_body_metadata():
     assert body == expected
 
 
-def test_create_request_body_download():
+def test_create_request_body_download() -> None:
     """Test the create_request_body_download function."""
     body = create_request_body_download("abcd", "efgh")
     expected = """
@@ -67,7 +67,7 @@ def test_create_request_body_download():
     assert body == expected
 
 
-def test_create_request_body_ids():
+def test_create_request_body_ids() -> None:
     """Test the create_request_body_ids function."""
     body = create_request_body_ids("abcd", [])
     expected = """
@@ -82,7 +82,8 @@ def test_create_request_body_ids():
       </soapenv:Body>
     </soapenv:Envelope>
     """.replace(
-        "FILTER", "\n".join([])
+        "FILTER",
+        "\n".join([]),
     )
     assert body == expected
 
@@ -108,7 +109,7 @@ def test_create_request_body_ids():
     assert body == expected
 
 
-def test_create_request_header():
+def test_create_request_header() -> None:
     """Test the create_request_header function."""
     header = create_request_header("allThesesMetadataRequest")
     expected = {