diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..c5420cd
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,19 @@
+repos:
+-   repo: https://github.com/PyCQA/isort
+    rev: 5.13.1
+    hooks:
+    - id: isort
+-   repo: https://github.com/psf/black
+    rev: 24.3.0
+    hooks:
+    - id: black
+-   repo: https://github.com/pycqa/flake8
+    rev: 7.0.0
+    hooks:
+    - id: flake8
+- repo: https://github.com/adamchainz/blacken-docs
+  rev: 1.16.0
+  hooks:
+  - id: blacken-docs
+    additional_dependencies:
+    - black==24.3.0
diff --git a/docs/asyncio_api.rst b/docs/asyncio_api.rst
index 2c6e568..c9a1e4a 100644
--- a/docs/asyncio_api.rst
+++ b/docs/asyncio_api.rst
@@ -14,9 +14,11 @@ You can use the method ``request_raw`` to perform individual requests:
 
     client = AsyncZyteAPI(api_key="YOUR_API_KEY")
 
+
     async def single_request(url):
         return await client.get({"url": url, "browserHtml": True})
 
+
     response = asyncio.run(single_request("https://books.toscrape.com"))
 
 .. tip:: You can skip the ``api_key`` parameter if you :ref:`use an environment
@@ -34,12 +36,10 @@ parallel, using multiple connections:
     from zyte_api import AsyncZyteAPI, create_session
     from zyte_api.aio.errors import RequestError
 
+
     async def extract_from(urls, n_conn):
         client = AsyncZyteAPI(n_conn=n_conn)
-        requests = [
-            {"url": url, "browserHtml": True}
-            for url in urls
-        ]
+        requests = [{"url": url, "browserHtml": True} for url in urls]
         async with create_session(n_conn) as session:
             res_iter = client.iter(requests, session=session)
             for fut in res_iter:
@@ -51,6 +51,7 @@ parallel, using multiple connections:
                     print(e, file=sys.stderr)
                     raise
 
+
     urls = ["https://toscrape.com", "https://books.toscrape.com"]
     asyncio.run(extract_from(urls, n_conn=15))
 
diff --git a/docs/conf.py b/docs/conf.py
index 4fa4cfd..5002ec5 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -12,19 +12,22 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('../'))
+
+import sphinx_rtd_theme
+
+sys.path.insert(0, os.path.abspath("../"))
 
 
 # -- Project information -----------------------------------------------------
 
-project = u'python-zyte-api'
-copyright = u'2021, Zyte Group Ltd'
-author = u'Zyte Group Ltd'
+project = "python-zyte-api"
+copyright = "2021, Zyte Group Ltd"
+author = "Zyte Group Ltd"
 
 # The short X.Y version
-version = u''
+version = ""
 # The full version, including alpha/beta/rc tags
-release = u'0.4.8'
+release = "0.4.8"
 
 
 # -- General configuration ---------------------------------------------------
@@ -37,37 +40,37 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'sphinx.ext.autodoc',
-    'sphinx.ext.intersphinx',
-    'sphinx.ext.ifconfig',
-    'sphinx.ext.viewcode',
-    'sphinx.ext.githubpages',
-    'sphinx.ext.autosummary',
+    "sphinx.ext.autodoc",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.ifconfig",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.githubpages",
+    "sphinx.ext.autosummary",
 ]
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 #
 # source_suffix = ['.rst', '.md']
-source_suffix = '.rst'
+source_suffix = ".rst"
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = 'en'
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path.
-exclude_patterns = [u'_build', 'Thumbs.db', '.DS_Store']
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = None
@@ -78,12 +81,11 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'sphinx_rtd_theme'
+html_theme = "sphinx_rtd_theme"
 
 # Add any paths that contain custom themes here, relative to this directory.
 # Add path to the RTD explicitly to robustify builds (otherwise might
 # fail in a clean Debian build env)
-import sphinx_rtd_theme
 html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # Theme options are theme-specific and customize the look and feel of a theme
@@ -111,7 +113,7 @@
 # -- Options for HTMLHelp output ---------------------------------------------
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = 'python-zyte-apidoc'
+htmlhelp_basename = "python-zyte-apidoc"
 
 
 # -- Options for LaTeX output ------------------------------------------------
@@ -120,15 +122,12 @@
     # The paper size ('letterpaper' or 'a4paper').
     #
     # 'papersize': 'letterpaper',
-
     # The font size ('10pt', '11pt' or '12pt').
     #
     # 'pointsize': '10pt',
-
     # Additional stuff for the LaTeX preamble.
     #
     # 'preamble': '',
-
     # Latex figure (float) alignment
     #
     # 'figure_align': 'htbp',
@@ -138,8 +137,13 @@
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'python-zyte-api.tex', u'python-zyte-api Documentation',
-     u'Zyte Group Ltd', 'manual'),
+    (
+        master_doc,
+        "python-zyte-api.tex",
+        "python-zyte-api Documentation",
+        "Zyte Group Ltd",
+        "manual",
+    ),
 ]
 
 
@@ -148,8 +152,7 @@
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    (master_doc, 'python-zyte-api', u'python-zyte-api Documentation',
-     [author], 1)
+    (master_doc, "python-zyte-api", "python-zyte-api Documentation", [author], 1)
 ]
 
 
@@ -159,9 +162,15 @@
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    (master_doc, 'python-zyte-api', u'python-zyte-api Documentation',
-     author, 'python-zyte-api', 'One line description of project.',
-     'Miscellaneous'),
+    (
+        master_doc,
+        "python-zyte-api",
+        "python-zyte-api Documentation",
+        author,
+        "python-zyte-api",
+        "One line description of project.",
+        "Miscellaneous",
+    ),
 ]
 
 
@@ -180,22 +189,31 @@
 # epub_uid = ''
 
 # A list of files that should not be packed into the epub file.
-epub_exclude_files = ['search.html']
+epub_exclude_files = ["search.html"]
 
 
 # -- Extension configuration -------------------------------------------------
 
 # -- Options for intersphinx extension ---------------------------------------
 intersphinx_mapping = {
-    'python': ('https://docs.python.org/3', None, ),
-    'aiohttp': ('https://docs.aiohttp.org/en/stable/', None, ),
-    'tenacity': ('https://tenacity.readthedocs.io/en/latest/', None, ),
+    "python": (
+        "https://docs.python.org/3",
+        None,
+    ),
+    "aiohttp": (
+        "https://docs.aiohttp.org/en/stable/",
+        None,
+    ),
+    "tenacity": (
+        "https://tenacity.readthedocs.io/en/latest/",
+        None,
+    ),
 }
 
 autodoc_default_options = {
     # 'special-members': '__init__,__call__',
     # 'undoc-members': True,
-    'exclude-members': '__weakref__'
+    "exclude-members": "__weakref__"
 }
 
 add_module_names = False
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..830e253
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,6 @@
+[tool.isort]
+profile = "black"
+multi_line_output = 3
+
+[tool.black]
+target-version = ["py38", "py39", "py310", "py311", "py312"]
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..5efe5f2
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,12 @@
+[flake8]
+ignore =
+    # Style issues handled by black.
+    E501,
+    E203,
+    W503,
+
+per-file-ignores =
+    # F401: Ignore "imported but unused" errors in __init__ files, as those
+    # imports are there to expose submodule functions so they can be imported
+    # directly from that module
+    zyte_api/__init__.py:F401
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 658699a..7383672 100755
--- a/setup.py
+++ b/setup.py
@@ -1,48 +1,49 @@
 #!/usr/bin/env python
 import os
-from setuptools import setup, find_packages
+
+from setuptools import find_packages, setup
 
 
 def get_version():
     about = {}
     here = os.path.abspath(os.path.dirname(__file__))
-    with open(os.path.join(here, 'zyte_api/__version__.py')) as f:
+    with open(os.path.join(here, "zyte_api/__version__.py")) as f:
         exec(f.read(), about)
-    return about['__version__']
+    return about["__version__"]
 
 
 setup(
-    name='zyte-api',
+    name="zyte-api",
     version=get_version(),
-    description='Python interface to Zyte API',
-    long_description=open('README.rst').read() + "\n\n" + open('CHANGES.rst').read(),
-    long_description_content_type='text/x-rst',
-    author='Zyte Group Ltd',
-    author_email='opensource@zyte.com',
-    url='https://github.com/zytedata/python-zyte-api',
-    packages=find_packages(exclude=['tests', 'examples']),
-    entry_points = {
-        'console_scripts': ['zyte-api=zyte_api.__main__:_main'],
+    description="Python interface to Zyte API",
+    long_description=open("README.rst").read() + "\n\n" + open("CHANGES.rst").read(),
+    long_description_content_type="text/x-rst",
+    author="Zyte Group Ltd",
+    author_email="opensource@zyte.com",
+    url="https://github.com/zytedata/python-zyte-api",
+    packages=find_packages(exclude=["tests", "examples"]),
+    entry_points={
+        "console_scripts": ["zyte-api=zyte_api.__main__:_main"],
     },
     install_requires=[
-        'aiohttp >= 3.8.0',
-        'attrs',
-        'brotli',
-        'runstats',
-        'tenacity',
-        'tqdm',
-        'w3lib >= 2.1.1',
+        "aiohttp >= 3.8.0",
+        "attrs",
+        "brotli",
+        "runstats",
+        "tenacity",
+        "tqdm",
+        "w3lib >= 2.1.1",
     ],
     classifiers=[
-        'Development Status :: 3 - Alpha',
-        'Intended Audience :: Developers',
-        'License :: OSI Approved :: BSD License',
-        'Natural Language :: English',
-        'Operating System :: OS Independent',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.8',
-        'Programming Language :: Python :: 3.9',
-        'Programming Language :: Python :: 3.10',
-        'Programming Language :: Python :: 3.11',
+        "Development Status :: 3 - Alpha",
+        "Intended Audience :: Developers",
+        "License :: OSI Approved :: BSD License",
+        "Natural Language :: English",
+        "Operating System :: OS Independent",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
     ],
 )
diff --git a/tests/mockserver.py b/tests/mockserver.py
index ea8fffb..8f4330d 100644
--- a/tests/mockserver.py
+++ b/tests/mockserver.py
@@ -4,18 +4,14 @@
 import sys
 import time
 from base64 import b64encode
-from contextlib import asynccontextmanager
 from importlib import import_module
 from subprocess import PIPE, Popen
-from typing import Any, Dict, Optional
+from typing import Any, Dict
 from urllib.parse import urlparse
 
-from pytest_twisted import ensureDeferred
 from twisted.internet import reactor
-from twisted.internet.defer import Deferred
-from twisted.internet.task import deferLater
 from twisted.web.resource import Resource
-from twisted.web.server import NOT_DONE_YET, Site
+from twisted.web.server import Site
 
 
 def get_ephemeral_port():
diff --git a/tests/test_async.py b/tests/test_async.py
index 0d15df0..eb93054 100644
--- a/tests/test_async.py
+++ b/tests/test_async.py
@@ -1,10 +1,8 @@
-from types import GeneratorType
+import pytest
 
 from zyte_api import AsyncZyteAPI
 from zyte_api.apikey import NoApiKey
 
-import pytest
-
 
 def test_api_key():
     AsyncZyteAPI(api_key="a")
@@ -15,8 +13,13 @@ def test_api_key():
 @pytest.mark.asyncio
 async def test_get(mockserver):
     client = AsyncZyteAPI(api_key="a", api_url=mockserver.urljoin("/"))
-    expected_result = {"url": "https://a.example", "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg=="}
-    actual_result = await client.get({"url": "https://a.example", "httpResponseBody": True})
+    expected_result = {
+        "url": "https://a.example",
+        "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg==",
+    }
+    actual_result = await client.get(
+        {"url": "https://a.example", "httpResponseBody": True}
+    )
     assert actual_result == expected_result
 
 
@@ -29,9 +32,15 @@ async def test_iter(mockserver):
         {"url": "https://b.example", "httpResponseBody": True},
     ]
     expected_results = [
-        {"url": "https://a.example", "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg=="},
+        {
+            "url": "https://a.example",
+            "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg==",
+        },
         Exception,
-        {"url": "https://b.example", "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg=="},
+        {
+            "url": "https://b.example",
+            "httpResponseBody": "PGh0bWw+PGJvZHk+SGVsbG88aDE+V29ybGQhPC9oMT48L2JvZHk+PC9odG1sPg==",
+        },
     ]
     actual_results = []
     for future in client.iter(queries):
diff --git a/tests/test_client.py b/tests/test_client.py
index cd4c214..ae34726 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -12,11 +12,11 @@
             USER_AGENT,
         ),
         (
-            f'scrapy-zyte-api/0.11.1 {USER_AGENT}',
-            f'scrapy-zyte-api/0.11.1 {USER_AGENT}',
+            f"scrapy-zyte-api/0.11.1 {USER_AGENT}",
+            f"scrapy-zyte-api/0.11.1 {USER_AGENT}",
         ),
     ),
 )
 def test_user_agent(user_agent, expected):
-    client = AsyncClient(api_key='123', api_url='http:\\test', user_agent=user_agent)
+    client = AsyncClient(api_key="123", api_url="http:\\test", user_agent=user_agent)
     assert client.user_agent == expected
diff --git a/tests/test_main.py b/tests/test_main.py
index 0087774..85573af 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,7 +1,7 @@
 import json
 import os
 from json import JSONDecodeError
-from unittest.mock import Mock, patch, AsyncMock
+from unittest.mock import AsyncMock, Mock, patch
 
 import pytest
 
diff --git a/tox.ini b/tox.ini
index fca46c5..fec688d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -31,3 +31,7 @@ deps =
 basepython = python3
 commands =
     sphinx-build -W -b html . {envtmpdir}/html
+
+[testenv:pre-commit]
+deps = pre-commit
+commands = pre-commit run --all-files --show-diff-on-failure
diff --git a/zyte_api/__main__.py b/zyte_api/__main__.py
index 3e03e70..b81dc63 100644
--- a/zyte_api/__main__.py
+++ b/zyte_api/__main__.py
@@ -10,12 +10,9 @@
 import tqdm
 from tenacity import retry_if_exception
 
-from zyte_api.aio.client import (
-    create_session,
-    AsyncClient,
-)
+from zyte_api.aio.client import AsyncClient, create_session
 from zyte_api.aio.retry import RetryFactory, _is_throttling_error
-from zyte_api.constants import ENV_VARIABLE, API_URL
+from zyte_api.constants import API_URL, ENV_VARIABLE
 from zyte_api.utils import _guess_intype
 
 
@@ -167,7 +164,7 @@ def _main(program_name="zyte-api"):
     p.add_argument(
         "--store-errors",
         help="when set to true, it includes all types of responses, and when set to false,"
-             " it includes only error-free responses in the output.",
+        " it includes only error-free responses in the output.",
     )
     args = p.parse_args()
     logging.basicConfig(stream=sys.stderr, level=getattr(logging, args.loglevel))
diff --git a/zyte_api/__version__.py b/zyte_api/__version__.py
index 5bf52d5..a3a9bd5 100644
--- a/zyte_api/__version__.py
+++ b/zyte_api/__version__.py
@@ -1 +1 @@
-__version__ = '0.4.8'
+__version__ = "0.4.8"
diff --git a/zyte_api/_async.py b/zyte_api/_async.py
index 8156bde..6553c5c 100644
--- a/zyte_api/_async.py
+++ b/zyte_api/_async.py
@@ -1,19 +1,18 @@
 import asyncio
 import time
 from functools import partial
-from typing import Any, Dict, Iterator, List, Optional, TYPE_CHECKING, Union
+from typing import TYPE_CHECKING, Any, Dict, Iterator, List, Optional
 
 import aiohttp
 from tenacity import AsyncRetrying
 
+from ._utils import _AIO_API_TIMEOUT
 from .aio.errors import RequestError
 from .aio.retry import zyte_api_retrying
 from .apikey import get_apikey
-from .constants import API_URL, API_TIMEOUT
+from .constants import API_URL
 from .stats import AggStats, ResponseStats
 from .utils import USER_AGENT, _process_query
-from ._utils import _AIO_API_TIMEOUT, create_session
-
 
 if TYPE_CHECKING:
     _ResponseFuture = asyncio.Future[Dict[str, Any]]
@@ -22,11 +21,9 @@
 
 
 def _post_func(session):
-    """ Return a function to send a POST request """
+    """Return a function to send a POST request"""
     if session is None:
-        return partial(aiohttp.request,
-                       method='POST',
-                       timeout=_AIO_API_TIMEOUT)
+        return partial(aiohttp.request, method="POST", timeout=_AIO_API_TIMEOUT)
     else:
         return session.post
 
@@ -52,7 +49,7 @@ async def get(
         self,
         query: dict,
         *,
-        endpoint: str = 'extract',
+        endpoint: str = "extract",
         session=None,
         handle_retries=True,
         retrying: Optional[AsyncRetrying] = None,
@@ -60,10 +57,7 @@ async def get(
         retrying = retrying or self.retrying
         post = _post_func(session)
         auth = aiohttp.BasicAuth(self.api_key)
-        headers = {
-            'User-Agent': self.user_agent,
-            'Accept-Encoding': 'br'
-        }
+        headers = {"User-Agent": self.user_agent, "Accept-Encoding": "br"}
 
         response_stats = []
         start_global = time.perf_counter()
@@ -125,7 +119,7 @@ def iter(
         self,
         queries: List[dict],
         *,
-        endpoint: str = 'extract',
+        endpoint: str = "extract",
         session: Optional[aiohttp.ClientSession] = None,
         handle_retries=True,
         retrying: Optional[AsyncRetrying] = None,
diff --git a/zyte_api/_utils.py b/zyte_api/_utils.py
index e547fb5..116206f 100644
--- a/zyte_api/_utils.py
+++ b/zyte_api/_utils.py
@@ -3,7 +3,6 @@
 
 from .constants import API_TIMEOUT
 
-
 # 120 seconds is probably too long, but we are concerned about the case with
 # many concurrent requests and some processing logic running in the same reactor,
 # thus, saturating the CPU. This will make timeouts more likely.
@@ -11,9 +10,8 @@
 
 
 def create_session(connection_pool_size=100, **kwargs) -> aiohttp.ClientSession:
-    """ Create a session with parameters suited for Zyte API """
-    kwargs.setdefault('timeout', _AIO_API_TIMEOUT)
+    """Create a session with parameters suited for Zyte API"""
+    kwargs.setdefault("timeout", _AIO_API_TIMEOUT)
     if "connector" not in kwargs:
-        kwargs["connector"] = TCPConnector(limit=connection_pool_size,
-                                           force_close=True)
+        kwargs["connector"] = TCPConnector(limit=connection_pool_size, force_close=True)
     return aiohttp.ClientSession(**kwargs)
diff --git a/zyte_api/aio/__init__.py b/zyte_api/aio/__init__.py
index b69b052..9833d38 100644
--- a/zyte_api/aio/__init__.py
+++ b/zyte_api/aio/__init__.py
@@ -1,3 +1,3 @@
 """
 Asyncio client for Zyte API
-"""
\ No newline at end of file
+"""
diff --git a/zyte_api/aio/client.py b/zyte_api/aio/client.py
index 68f2530..c2336db 100644
--- a/zyte_api/aio/client.py
+++ b/zyte_api/aio/client.py
@@ -4,23 +4,20 @@
 
 import asyncio
 import time
-from functools import partial
-from typing import Optional, Iterator, List
+from typing import Iterator, List, Optional
 from warnings import warn
 
 import aiohttp
-from aiohttp import TCPConnector
 from tenacity import AsyncRetrying
 
-from .errors import RequestError
-from .retry import zyte_api_retrying
 from .._async import _post_func
-from .._utils import _AIO_API_TIMEOUT as AIO_API_TIMEOUT, create_session
+from .._utils import create_session  # noqa: F401
 from ..apikey import get_apikey
-from ..constants import API_URL, API_TIMEOUT
+from ..constants import API_URL
 from ..stats import AggStats, ResponseStats
 from ..utils import USER_AGENT, _process_query
-
+from .errors import RequestError
+from .retry import zyte_api_retrying
 
 warn(
     (
@@ -33,13 +30,15 @@
 
 
 class AsyncClient:
-    def __init__(self, *,
-                 api_key=None,
-                 api_url=API_URL,
-                 n_conn=15,
-                 retrying: Optional[AsyncRetrying] = None,
-                 user_agent: Optional[str] = None,
-                 ):
+    def __init__(
+        self,
+        *,
+        api_key=None,
+        api_url=API_URL,
+        n_conn=15,
+        retrying: Optional[AsyncRetrying] = None,
+        user_agent: Optional[str] = None,
+    ):
         self.api_key = get_apikey(api_key)
         self.api_url = api_url
         self.n_conn = n_conn
@@ -47,19 +46,19 @@ def __init__(self, *,
         self.retrying = retrying or zyte_api_retrying
         self.user_agent = user_agent or USER_AGENT
 
-    async def request_raw(self, query: dict, *,
-                          endpoint: str = 'extract',
-                          session=None,
-                          handle_retries=True,
-                          retrying: Optional[AsyncRetrying] = None,
-                          ):
+    async def request_raw(
+        self,
+        query: dict,
+        *,
+        endpoint: str = "extract",
+        session=None,
+        handle_retries=True,
+        retrying: Optional[AsyncRetrying] = None,
+    ):
         retrying = retrying or self.retrying
         post = _post_func(session)
         auth = aiohttp.BasicAuth(self.api_key)
-        headers = {
-            'User-Agent': self.user_agent,
-            'Accept-Encoding': 'br'
-        }
+        headers = {"User-Agent": self.user_agent, "Accept-Encoding": "br"}
 
         response_stats = []
         start_global = time.perf_counter()
@@ -117,13 +116,14 @@ async def request():
 
         return result
 
-    def request_parallel_as_completed(self,
-                                      queries: List[dict],
-                                      *,
-                                      endpoint: str = 'extract',
-                                      session: Optional[aiohttp.ClientSession] = None,
-                                      ) -> Iterator[asyncio.Future]:
-        """ Send multiple requests to Zyte API in parallel.
+    def request_parallel_as_completed(
+        self,
+        queries: List[dict],
+        *,
+        endpoint: str = "extract",
+        session: Optional[aiohttp.ClientSession] = None,
+    ) -> Iterator[asyncio.Future]:
+        """Send multiple requests to Zyte API in parallel.
         Return an `asyncio.as_completed` iterator.
 
         ``queries`` is a list of requests to process (dicts).
@@ -136,8 +136,6 @@ def request_parallel_as_completed(self,
 
         async def _request(query):
             async with sem:
-                return await self.request_raw(query,
-                    endpoint=endpoint,
-                    session=session)
+                return await self.request_raw(query, endpoint=endpoint, session=session)
 
         return asyncio.as_completed([_request(query) for query in queries])
diff --git a/zyte_api/aio/errors.py b/zyte_api/aio/errors.py
index 8b3005c..cf12e80 100644
--- a/zyte_api/aio/errors.py
+++ b/zyte_api/aio/errors.py
@@ -9,10 +9,11 @@
 
 
 class RequestError(ClientResponseError):
-    """ Exception which is raised when Request-level error is returned.
+    """Exception which is raised when Request-level error is returned.
     In contrast with ClientResponseError, it allows to inspect response
     content.
     """
+
     def __init__(self, *args, **kwargs):
         self.response_content = kwargs.pop("response_content")
         self.request_id = kwargs.pop("request_id", None)
@@ -25,6 +26,8 @@ def parsed(self):
         return ParsedError.from_body(self.response_content)
 
     def __str__(self):
-        return f"RequestError: {self.status}, message={self.message}, " \
-               f"headers={self.headers}, body={self.response_content}, " \
-               f"request_id={self.request_id}"
+        return (
+            f"RequestError: {self.status}, message={self.message}, "
+            f"headers={self.headers}, body={self.response_content}, "
+            f"request_id={self.request_id}"
+        )
diff --git a/zyte_api/aio/retry.py b/zyte_api/aio/retry.py
index 1f8b4fb..39299b5 100644
--- a/zyte_api/aio/retry.py
+++ b/zyte_api/aio/retry.py
@@ -9,22 +9,24 @@
 
 from aiohttp import client_exceptions
 from tenacity import (
+    AsyncRetrying,
+    RetryCallState,
+    after_log,
+    before_log,
+    before_sleep_log,
+    retry_base,
+    retry_if_exception,
+    stop_after_attempt,
+    stop_after_delay,
     wait_chain,
     wait_fixed,
-    wait_random_exponential,
     wait_random,
-    stop_after_attempt,
-    stop_after_delay,
-    retry_if_exception,
-    RetryCallState,
-    before_sleep_log,
-    after_log, AsyncRetrying, before_log, retry_base,
+    wait_random_exponential,
 )
 from tenacity.stop import stop_never
 
 from .errors import RequestError
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -62,6 +64,7 @@ class RetryFactory:
     """
     Build custom retry configuration
     """
+
     retry_condition: retry_base = (
         retry_if_exception(_is_throttling_error)
         | retry_if_exception(_is_network_error)
@@ -71,19 +74,18 @@ class RetryFactory:
     throttling_wait = wait_chain(
         # always wait 20-40s first
         wait_fixed(20) + wait_random(0, 20),
-
         # wait 20-40s again
         wait_fixed(20) + wait_random(0, 20),
-
         # wait from 30 to 630s, with full jitter and exponentially
         # increasing max wait time
-        wait_fixed(30) + wait_random_exponential(multiplier=1, max=600)
+        wait_fixed(30) + wait_random_exponential(multiplier=1, max=600),
     )
 
     # connection errors, other client and server failures
     network_error_wait = (
         # wait from 3s to ~1m
-        wait_random(3, 7) + wait_random_exponential(multiplier=1, max=55)
+        wait_random(3, 7)
+        + wait_random_exponential(multiplier=1, max=55)
     )
     temporary_download_error_wait = network_error_wait
     throttling_stop = stop_never
diff --git a/zyte_api/apikey.py b/zyte_api/apikey.py
index f9b0f80..c1cc70b 100644
--- a/zyte_api/apikey.py
+++ b/zyte_api/apikey.py
@@ -10,11 +10,13 @@ class NoApiKey(Exception):
 
 
 def get_apikey(key: Optional[str] = None) -> str:
-    """ Return API key, probably loading it from an environment variable """
+    """Return API key, probably loading it from an environment variable"""
     if key is not None:
         return key
     try:
         return os.environ[ENV_VARIABLE]
     except KeyError:
-        raise NoApiKey("API key not found. Please set {} "
-                       "environment variable.".format(ENV_VARIABLE))
+        raise NoApiKey(
+            "API key not found. Please set {} "
+            "environment variable.".format(ENV_VARIABLE)
+        )
diff --git a/zyte_api/constants.py b/zyte_api/constants.py
index 926577d..a433302 100644
--- a/zyte_api/constants.py
+++ b/zyte_api/constants.py
@@ -1,10 +1,10 @@
 # -*- coding: utf-8 -*-
 
 # Name of the environment variable with the API key
-ENV_VARIABLE = 'ZYTE_API_KEY'
+ENV_VARIABLE = "ZYTE_API_KEY"
 
 # API URL
-API_URL = 'https://api.zyte.com/v1/'
+API_URL = "https://api.zyte.com/v1/"
 
 # Default timeout that server uses. Client timeouts should be larger than that.
 API_TIMEOUT = 200
diff --git a/zyte_api/errors.py b/zyte_api/errors.py
index b608bf1..8088b54 100644
--- a/zyte_api/errors.py
+++ b/zyte_api/errors.py
@@ -6,13 +6,14 @@
 
 @attr.s(auto_attribs=True)
 class ParsedError:
-    """ Parsed error from Zyte API """
+    """Parsed error from Zyte API"""
+
     response_body: bytes
     data: Optional[dict]
     parse_error: Optional[str]
 
     @classmethod
-    def from_body(cls, response_body: bytes) -> 'ParsedError':
+    def from_body(cls, response_body: bytes) -> "ParsedError":
         data = None
         parse_error = None
 
@@ -25,12 +26,8 @@ def from_body(cls, response_body: bytes) -> 'ParsedError':
             except (json.JSONDecodeError, UnicodeDecodeError) as _:  # noqa: F841
                 parse_error = "bad_json"
 
-        return cls(
-            response_body=response_body,
-            data=data,
-            parse_error=parse_error
-        )
+        return cls(response_body=response_body, data=data, parse_error=parse_error)
 
     @property
     def type(self) -> Optional[str]:
-        return (self.data or {}).get('type', None)
+        return (self.data or {}).get("type", None)
diff --git a/zyte_api/stats.py b/zyte_api/stats.py
index 1789ee5..42c7b6a 100644
--- a/zyte_api/stats.py
+++ b/zyte_api/stats.py
@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
-from typing import Optional
-from collections import Counter
 import functools
 import time
+from collections import Counter
+from typing import Optional
 
 import attr
 from runstats import Statistics
@@ -17,6 +17,7 @@ def wrapper(*args, **kwargs):
             return meth(*args, **kwargs)
         except ZeroDivisionError:
             return 0
+
     return wrapper
 
 
@@ -26,9 +27,13 @@ def __init__(self):
         self.time_total_stats = Statistics()
 
         self.n_success = 0  # number of successful results returned to the user
-        self.n_fatal_errors = 0  # number of errors returned to the user, after all retries
+        self.n_fatal_errors = (
+            0  # number of errors returned to the user, after all retries
+        )
 
-        self.n_attempts = 0  # total amount of requests made to Zyte API, including retries
+        self.n_attempts = (
+            0  # total amount of requests made to Zyte API, including retries
+        )
         self.n_429 = 0  # number of 429 (throttling) responses
         self.n_errors = 0  # number of errors, including errors which were retried
 
@@ -46,25 +51,29 @@ def __str__(self):
             self.error_ratio(),
             self.n_success,
             self.n_processed,
-            self.success_ratio()
+            self.success_ratio(),
         )
 
     def summary(self):
         return (
-            "\n" +
-            "Summary\n" +
-            "-------\n" +
-            "Mean connection time:     {:0.2f}\n".format(self.time_connect_stats.mean()) +
-            "Mean response time:       {:0.2f}\n".format(self.time_total_stats.mean()) +
-            "Throttle ratio:           {:0.1%}\n".format(self.throttle_ratio()) +
-            "Attempts:                 {}\n".format(self.n_attempts) +
-            "Errors:                   {:0.1%}, fatal: {}, non fatal: {}\n".format(
+            "\n"
+            + "Summary\n"
+            + "-------\n"
+            + "Mean connection time:     {:0.2f}\n".format(
+                self.time_connect_stats.mean()
+            )
+            + "Mean response time:       {:0.2f}\n".format(self.time_total_stats.mean())
+            + "Throttle ratio:           {:0.1%}\n".format(self.throttle_ratio())
+            + "Attempts:                 {}\n".format(self.n_attempts)
+            + "Errors:                   {:0.1%}, fatal: {}, non fatal: {}\n".format(
                 self.error_ratio(),
                 self.n_fatal_errors,
-                self.n_errors - self.n_fatal_errors) +
-            "Successful URLs:          {} of {}\n".format(
-                self.n_success, self.n_processed) +
-            "Success ratio:            {:0.1%}\n".format(self.success_ratio())
+                self.n_errors - self.n_fatal_errors,
+            )
+            + "Successful URLs:          {} of {}\n".format(
+                self.n_success, self.n_processed
+            )
+            + "Success ratio:            {:0.1%}\n".format(self.success_ratio())
         )
 
     @zero_on_division_error
@@ -81,7 +90,7 @@ def success_ratio(self):
 
     @property
     def n_processed(self):
-        """ Total number of processed URLs """
+        """Total number of processed URLs"""
         return self.n_success + self.n_fatal_errors
 
 
diff --git a/zyte_api/utils.py b/zyte_api/utils.py
index 7767a9b..1b24a60 100644
--- a/zyte_api/utils.py
+++ b/zyte_api/utils.py
@@ -5,7 +5,7 @@
 
 from .__version__ import __version__
 
-USER_AGENT = f'python-zyte-api/{__version__}'
+USER_AGENT = f"python-zyte-api/{__version__}"
 
 
 def _guess_intype(file_name, lines):
@@ -16,7 +16,7 @@ def _guess_intype(file_name, lines):
     if extension == "txt":
         return "txt"
 
-    if re.search(r'^\s*\{', lines[0]):
+    if re.search(r"^\s*\{", lines[0]):
         return "jl"
 
     return "txt"