diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 9e350e041..348ec4361 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -11,7 +11,7 @@ updates:
       interval: "daily"
 
   - package-ecosystem: "pip" # See documentation for possible values
-    directory: "/dev_requirements/" # Location of package manifests
+    directory: "/" # Location of package manifests
     schedule:
       interval: "weekly"
   # Maintain dependencies for GitHub Actions
diff --git a/.github/workflows/python-publish-scheduled.yml b/.github/workflows/python-publish-scheduled.yml
index e35f94be6..a024bc45d 100644
--- a/.github/workflows/python-publish-scheduled.yml
+++ b/.github/workflows/python-publish-scheduled.yml
@@ -106,7 +106,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r dev_requirements/requirements-packaging.txt
+          pip install .[packaging]
       - name: Build wheel and source distributions
         run: python -m build
       - name: Publish distribution 📦 to PyPI
diff --git a/.github/workflows/python-publish.yml b/.github/workflows/python-publish.yml
index 647384a74..82e78ebc5 100644
--- a/.github/workflows/python-publish.yml
+++ b/.github/workflows/python-publish.yml
@@ -30,7 +30,11 @@ jobs:
           tox -e tests
   check_version_tag:
     name: Check if the version tag is correct
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        python-version: [ "3.12" ]
+        os: [ ubuntu-latest ]
     steps:
       - name: Check out Git repository
         uses: actions/checkout@v4
@@ -55,7 +59,11 @@ jobs:
           --gh-token ${{ secrets.GITHUB_TOKEN }} --major-bump-disallowed
   json_schemas:
     name: Generate JSON-Schemas
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        python-version: [ "3.12" ]
+        os: [ ubuntu-latest ]
     needs: [tests, check_version_tag]
     concurrency: build-n-publish-json-schemas
     steps:
@@ -185,7 +193,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r dev_requirements/requirements-packaging.txt
+          pip install .[packaging]
       - name: Build wheel and source distributions
         run: python -m build
       - name: Publish distribution 📦 to PyPI
diff --git a/dev_requirements/requirements-coverage.in b/dev_requirements/requirements-coverage.in
deleted file mode 100644
index d1e1a8090..000000000
--- a/dev_requirements/requirements-coverage.in
+++ /dev/null
@@ -1,2 +0,0 @@
-# specific requirements for the tox coverage env
-coverage
diff --git a/dev_requirements/requirements-coverage.txt b/dev_requirements/requirements-coverage.txt
deleted file mode 100644
index dfb8459ed..000000000
--- a/dev_requirements/requirements-coverage.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-# SHA1:6dafbcf610e9f81897b65ee9142715ab2e793f9e
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-coverage==7.6.4
-    # via -r requirements-coverage.in
diff --git a/dev_requirements/requirements-formatting.in b/dev_requirements/requirements-formatting.in
deleted file mode 100644
index 41e6b86a9..000000000
--- a/dev_requirements/requirements-formatting.in
+++ /dev/null
@@ -1,3 +0,0 @@
-# specific requirements for the formatting envs
-black
-isort
diff --git a/dev_requirements/requirements-formatting.txt b/dev_requirements/requirements-formatting.txt
deleted file mode 100644
index ca9be611a..000000000
--- a/dev_requirements/requirements-formatting.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-# SHA1:2c7ffcd29222de3114c7f7994911f1b69d06b6b3
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-black==24.10.0
-    # via -r dev_requirements/requirements-formatting.in
-click==8.1.7
-    # via black
-isort==5.13.2
-    # via -r dev_requirements/requirements-formatting.in
-mypy-extensions==1.0.0
-    # via black
-packaging==24.0
-    # via black
-pathspec==0.12.1
-    # via black
-platformdirs==4.2.0
-    # via black
diff --git a/dev_requirements/requirements-json_schemas.in b/dev_requirements/requirements-json_schemas.in
deleted file mode 100644
index dca9a9096..000000000
--- a/dev_requirements/requirements-json_schemas.in
+++ /dev/null
@@ -1 +0,0 @@
-click
diff --git a/dev_requirements/requirements-json_schemas.txt b/dev_requirements/requirements-json_schemas.txt
deleted file mode 100644
index 3570e6169..000000000
--- a/dev_requirements/requirements-json_schemas.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-# SHA1:b93ec56608fb302fea7a8019d7c0e8e7239fc033
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-click==8.1.7
-    # via -r dev_requirements\requirements-json_schemas.in
-colorama==0.4.6
-    # via click
diff --git a/dev_requirements/requirements-linting.in b/dev_requirements/requirements-linting.in
deleted file mode 100644
index 787ac85b3..000000000
--- a/dev_requirements/requirements-linting.in
+++ /dev/null
@@ -1,2 +0,0 @@
-# specific requirements for the tox linting env
-pylint
diff --git a/dev_requirements/requirements-linting.txt b/dev_requirements/requirements-linting.txt
deleted file mode 100644
index ca5f84762..000000000
--- a/dev_requirements/requirements-linting.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-# SHA1:0e15f8789b9d62fe90d1f1b0b6a7e32f13b99b19
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-astroid==3.2.4
-    # via pylint
-dill==0.3.8
-    # via pylint
-isort==5.13.2
-    # via pylint
-mccabe==0.7.0
-    # via pylint
-platformdirs==4.2.0
-    # via pylint
-pylint==3.2.7
-    # via -r requirements-linting.in
-tomlkit==0.12.4
-    # via pylint
diff --git a/dev_requirements/requirements-packaging.in b/dev_requirements/requirements-packaging.in
deleted file mode 100644
index 9fef06202..000000000
--- a/dev_requirements/requirements-packaging.in
+++ /dev/null
@@ -1,3 +0,0 @@
-# requirements for the hatchling build system
-build
-twine
diff --git a/dev_requirements/requirements-packaging.txt b/dev_requirements/requirements-packaging.txt
deleted file mode 100644
index 236a3fe40..000000000
--- a/dev_requirements/requirements-packaging.txt
+++ /dev/null
@@ -1,79 +0,0 @@
-# SHA1:93e4fbf2b6cce1574fe3d5315360512fa9927699
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-build==1.2.2.post1
-    # via -r requirements-packaging.in
-certifi==2024.7.4
-    # via requests
-cffi==1.16.0
-    # via cryptography
-charset-normalizer==3.3.2
-    # via requests
-cryptography==43.0.1
-    # via secretstorage
-docutils==0.21.1
-    # via readme-renderer
-idna==3.7
-    # via requests
-importlib-metadata==7.1.0
-    # via twine
-jaraco-classes==3.4.0
-    # via keyring
-jaraco-context==5.3.0
-    # via keyring
-jaraco-functools==4.0.1
-    # via keyring
-jeepney==0.8.0
-    # via
-    #   keyring
-    #   secretstorage
-keyring==25.1.0
-    # via twine
-markdown-it-py==3.0.0
-    # via rich
-mdurl==0.1.2
-    # via markdown-it-py
-more-itertools==10.2.0
-    # via
-    #   jaraco-classes
-    #   jaraco-functools
-nh3==0.2.17
-    # via readme-renderer
-packaging==24.0
-    # via build
-pkginfo==1.10.0
-    # via twine
-pycparser==2.22
-    # via cffi
-pygments==2.17.2
-    # via
-    #   readme-renderer
-    #   rich
-pyproject-hooks==1.0.0
-    # via build
-readme-renderer==43.0
-    # via twine
-requests==2.32.3
-    # via
-    #   requests-toolbelt
-    #   twine
-requests-toolbelt==1.0.0
-    # via twine
-rfc3986==2.0.0
-    # via twine
-rich==13.7.1
-    # via twine
-secretstorage==3.3.3
-    # via keyring
-twine==5.1.1
-    # via -r requirements-packaging.in
-urllib3==2.2.2
-    # via
-    #   requests
-    #   twine
-zipp==3.19.1
-    # via importlib-metadata
diff --git a/dev_requirements/requirements-tests.in b/dev_requirements/requirements-tests.in
deleted file mode 100644
index 396df84f3..000000000
--- a/dev_requirements/requirements-tests.in
+++ /dev/null
@@ -1,4 +0,0 @@
-# specific requirements for the tox tests env
-pytest
-pytest-datafiles
-dictdiffer
diff --git a/dev_requirements/requirements-tests.txt b/dev_requirements/requirements-tests.txt
deleted file mode 100644
index b3decb3bb..000000000
--- a/dev_requirements/requirements-tests.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-# SHA1:d8bf34f7830b949c538f22e73d2b6ebb2065a573
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-dictdiffer==0.9.0
-    # via -r dev_requirements/requirements-tests.in
-iniconfig==2.0.0
-    # via pytest
-packaging==24.0
-    # via pytest
-pluggy==1.5.0
-    # via pytest
-pytest==8.3.3
-    # via
-    #   -r dev_requirements/requirements-tests.in
-    #   pytest-datafiles
-pytest-datafiles==3.0.0
-    # via -r dev_requirements/requirements-tests.in
diff --git a/dev_requirements/requirements-type_check.in b/dev_requirements/requirements-type_check.in
deleted file mode 100644
index 09356ab1e..000000000
--- a/dev_requirements/requirements-type_check.in
+++ /dev/null
@@ -1,5 +0,0 @@
-# specific requirements for the tox type_check environment
-mypy
-types-requests
-networkx-stubs
-pytest
diff --git a/dev_requirements/requirements-type_check.txt b/dev_requirements/requirements-type_check.txt
deleted file mode 100644
index cd2a4b4d6..000000000
--- a/dev_requirements/requirements-type_check.txt
+++ /dev/null
@@ -1,29 +0,0 @@
-# SHA1:9a286c239b1bb587f83dac5fba3e8a2ebfa4029b
-#
-# This file is autogenerated by pip-compile-multi
-# To update, run:
-#
-#    pip-compile-multi
-#
-iniconfig==2.0.0
-    # via pytest
-mypy==1.13.0
-    # via -r dev_requirements/requirements-type_check.in
-mypy-extensions==1.0.0
-    # via mypy
-networkx==3.4.2
-    # via networkx-stubs
-networkx-stubs==0.0.1
-    # via -r dev_requirements/requirements-type_check.in
-packaging==24.0
-    # via pytest
-pluggy==1.5.0
-    # via pytest
-pytest==8.3.3
-    # via -r dev_requirements/requirements-type_check.in
-types-requests==2.32.0.20241016
-    # via -r dev_requirements/requirements-type_check.in
-typing-extensions==4.11.0
-    # via mypy
-urllib3==2.2.2
-    # via types-requests
diff --git a/pyproject.toml b/pyproject.toml
index 2a0333f7b..aeb946d7a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,10 +27,47 @@ classifiers = [
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
 ]
-# This list must be in synq with the ./requirements.in file!
-dependencies = ["iso3166", "pydantic>=2.0.0", "pyhumps"]
+dependencies = [
+  "iso3166",
+  "pydantic>=2.0.0",
+  "pyhumps"
+]# This list must be in synq with the ./requirements. in file!
+# any dependency added here should also be added in docs/requirements.in and docs/requirements.txt respectively
 dynamic = ["readme", "version"]
 
+[project.optional-dependencies]
+coverage = [
+    "coverage==7.6.4"
+]
+formatting = [
+    "black==24.10.0",
+    "isort==5.13.2"
+]
+json_schema = [
+    "click==8.1.7"
+]
+linting = [
+    "pylint==3.2.7"
+]
+spell_check = [
+    "codespell==2.3.0"
+]
+packaging = [
+    "build==1.2.2",
+    "twine==5.1.1"
+]
+tests = [
+    "dictdiffer==0.9.0",
+    "pytest==8.3.3",
+    "pytest-datafiles==3.0.0"
+]
+type_check = [
+    "mypy==1.13.0",
+    "networkx-stubs==0.0.1",
+    "pytest==8.3.3",
+    "types-requests==2.32.0.20241016"
+]
+
 [project.urls]
 Changelog = "https://github.com/bo4e/bo4e-python/releases"
 Homepage = "https://github.com/bo4e/bo4e-python"
diff --git a/requirements.in b/requirements.in
deleted file mode 100644
index 8cb2e76d3..000000000
--- a/requirements.in
+++ /dev/null
@@ -1,3 +0,0 @@
-iso3166
-pydantic>=2.0.0
-pyhumps
diff --git a/requirements.txt b/requirements.txt
index cc5fbe406..d3bf290bc 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,18 +2,18 @@
 # This file is autogenerated by pip-compile with Python 3.12
 # by the following command:
 #
-#    pip-compile requirements.in
+#    pip-compile pyproject.toml
 #
 annotated-types==0.5.0
     # via pydantic
 iso3166==2.1.1
-    # via -r requirements.in
+    # via -r pyproject.toml
 pydantic==2.8.2
-    # via -r requirements.in
+    # via -r pyproject.toml
 pydantic-core==2.20.1
     # via pydantic
 pyhumps==3.8.0
-    # via -r requirements.in
+    # via -r pyproject.toml
 typing-extensions==4.11.0
     # via
     #   pydantic
diff --git a/tox.ini b/tox.ini
index bfe8aaccb..d89180590 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,14 +15,14 @@ commands = python -m pip install --upgrade pip
 [testenv:tests]
 deps =
     -r requirements.txt
-    -r dev_requirements/requirements-tests.txt
+    .[tests]
 commands = python -m pytest --basetemp={envtmpdir} {posargs}
 
 
 [testenv:linting]
 deps =
     -r requirements.txt
-    -r dev_requirements/requirements-linting.txt
+    .[linting]
     {[testenv:docs]deps}
     {[testenv:generate_json_schemas]deps}
 commands =
@@ -38,7 +38,7 @@ deps =
     -rrequirements.txt
     {[testenv:docs]deps}
     {[testenv:generate_json_schemas]deps}
-    -r dev_requirements/requirements-type_check.txt
+    .[type_check]
 commands =
     mypy --show-error-codes src/bo4e
     mypy --show-error-codes tests
@@ -51,7 +51,7 @@ commands =
 usedevelop = True
 deps =
     {[testenv:tests]deps}
-    -r dev_requirements/requirements-coverage.txt
+    .[coverage]
 commands =
     coverage run -m pytest --basetemp={envtmpdir} {posargs}
     coverage html --omit .tox/*,tests/*
@@ -66,14 +66,13 @@ deps =
     {[testenv:type_check]deps}
     {[testenv:coverage]deps}
     {[testenv:docs]deps}
-    -r dev_requirements/requirements-formatting.txt
+    .[formatting]
     # Replace by any tag/version: https://github.com/psf/black/tags
     # and change the pre-commit-config.yaml accordingly
     pip-tools
     pre-commit
 commands =
     python -m pip install --upgrade pip
-    pip-compile requirements.in
     pip install -r requirements.txt
     pre-commit install
 
@@ -97,7 +96,7 @@ commands =
 [testenv:bo4e-from-pip]
 basepython = python3.10
 skip_install = true
-deps = -r dev_requirements/requirements-tests.txt
+deps = .[tests]
 commands =
     pip install bo4e
     python -m pytest
@@ -106,7 +105,7 @@ commands =
 [testenv:test_packaging]
 skip_install = true
 deps =
-    -r dev_requirements/requirements-packaging.txt
+    .[packaging]
 commands =
     python -m build
     twine check dist/*
@@ -116,7 +115,7 @@ commands =
 usedevelop = True
 deps =
     -r requirements.txt
-    -r dev_requirements/requirements-json_schemas.txt
+    .[json_schemas]
 setenv =
     TARGET_VERSION = {env:TARGET_VERSION:}
 # This environment variable will be set inside the release workflow