diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..7e4b296
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,51 @@
+repos:
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v2.4.0
+  hooks:
+  - id: trailing-whitespace
+  - id: check-json
+  - id: check-yaml
+
+- repo: https://gitlab.com/pycqa/flake8
+  rev: 3.8.3
+  hooks:
+  - id: flake8
+
+- repo: https://github.com/codespell-project/codespell
+  rev: v1.16.0
+  hooks:
+  - id: codespell
+    exclude: ^(swh/loader/package/.*[/]+tests/data/.*)$
+    entry: codespell --ignore-words-list=iff
+
+- repo: local
+  hooks:
+  - id: mypy
+    name: mypy
+    entry: mypy
+    args: [swh]
+    pass_filenames: false
+    language: system
+    types: [python]
+
+- repo: https://github.com/PyCQA/isort
+  rev: 5.5.2
+  hooks:
+  - id: isort
+
+- repo: https://github.com/python/black
+  rev: 19.10b0
+  hooks:
+  - id: black
+
+# unfortunately, we are far from being able to enable this...
+# - repo: https://github.com/PyCQA/pydocstyle.git
+#   rev: 4.0.0
+#   hooks:
+#   - id: pydocstyle
+#     name: pydocstyle
+#     description: pydocstyle is a static analysis tool for checking compliance with Python docstring conventions.
+#     entry: pydocstyle --convention=google
+#     language: python
+#     types: [python]
+
diff --git a/docs/README.rst b/docs/README.rst
index 1b58ae3..3d3ed78 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -1,15 +1,4 @@
-.. _swh-loader-bzr:
-
 Software Heritage - Bazaar/Breezy loader
 ========================================
 
 Loader for `Bazaar <http://bazaar.canonical.com/en/>`_ and `Breezy <https://www.breezy-vcs.org/>`_ repositories. Breezy is a friendly fork of Bazaar that supports the Bazaar file format and network protocol.
-
-
-Reference Documentation
------------------------
-
-.. toctree::
-   :maxdepth: 2
-
-   /apidoc/swh.loader.bzr
diff --git a/docs/index.rst b/docs/index.rst
index 00cafe5..bc094db 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -1,15 +1,16 @@
-.. _swh-py-template:
+.. _swh-loader-bzr:
 
 .. include:: README.rst
 
 .. toctree::
    :maxdepth: 2
    :caption: Contents:
 
+   how-bzr-works
 
 Indices and tables
 ------------------
 
 * :ref:`genindex`
 * :ref:`modindex`
 * :ref:`search`
diff --git a/swh/__init__.py b/swh/__init__.py
index e780381..b36383a 100644
--- a/swh/__init__.py
+++ b/swh/__init__.py
@@ -1,4 +1,3 @@
 from pkgutil import extend_path
-from typing import Iterable
 
-__path__: Iterable[str] = extend_path(__path__, __name__)
+__path__ = extend_path(__path__, __name__)
diff --git a/tox.ini b/tox.ini
index f5d7c1e..c27d4ab 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,73 +1,73 @@
 [tox]
 envlist=black,flake8,mypy,py3
 
 [testenv]
 extras =
   testing
 deps =
   pytest-cov
 commands =
   pytest --doctest-modules \
          {envsitepackagesdir}/swh/foo \
          --cov={envsitepackagesdir}/swh/foo \
          --cov-branch {posargs}
 
 [testenv:black]
 skip_install = true
 deps =
   black==19.10b0
 commands =
   {envpython} -m black --check swh
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8
 
 [testenv:mypy]
 extras =
   testing
 deps =
-  mypy
+  mypy==0.920
 commands =
   mypy swh
 
 # build documentation outside swh-environment using the current
 # git HEAD of swh-docs, is executed on CI for each diff to prevent
 # breaking doc build
 [testenv:sphinx]
 whitelist_externals = make
 usedevelop = true
 extras =
   testing
 deps =
   # fetch and install swh-docs in develop mode
   -e git+https://forge.softwareheritage.org/source/swh-docs#egg=swh.docs
 
 setenv =
   SWH_PACKAGE_DOC_TOX_BUILD = 1
   # turn warnings into errors
   SPHINXOPTS = -W
 commands =
   make -I ../.tox/sphinx/src/swh-docs/swh/ -C docs
 
 
 # build documentation only inside swh-environment using local state
 # of swh-docs package
 [testenv:sphinx-dev]
 whitelist_externals = make
 usedevelop = true
 extras =
   testing
 deps =
   # install swh-docs in develop mode
   -e ../swh-docs
 
 setenv =
   SWH_PACKAGE_DOC_TOX_BUILD = 1
   # turn warnings into errors
   SPHINXOPTS = -W
 commands =
   make -I ../.tox/sphinx-dev/src/swh-docs/swh/ -C docs