-* [behave test framework](https://behave.readthedocs.io) >= 1.2.5
-* [phpunit](https://phpunit.de) >= 7.3
-* [PHP CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer)
+* [behave test framework](https://behave.readthedocs.io) >= 1.2.6
+* [flake8](https://flake8.pycqa.org/en/stable/) (CI always runs the latest version from pip)
+* [mypy](http://mypy-lang.org/) (plus typing information for external libs)
+* [Python Typing Extensions](https://github.com/python/typing_extensions) (for Python < 3.9)
+* [pytest](https://pytest.org)
+* [pytest-asyncio](https://pytest-asyncio.readthedocs.io)
+
+For testing the Python search frontend, you need to install extra dependencies
+depending on your choice of webserver framework:
+
+* [httpx](https://www.python-httpx.org/) (Starlette only)
+* [asgi-lifespan](https://github.com/florimondmanca/asgi-lifespan) (Starlette only)