diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f9ec0b8..d4401ef 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -33,6 +33,9 @@ jobs:
       - name: Lint with ruff
         run: poetry run ruff .
 
+      - name: Format with ruff
+        run: poetry run ruff format . --check
+
       - name: Lint with mypy
         run: poetry run mypy .
 
diff --git a/.vim/.vim/coc-settings.json b/.vim/.vim/coc-settings.json
new file mode 100644
index 0000000..d542a72
--- /dev/null
+++ b/.vim/.vim/coc-settings.json
@@ -0,0 +1,19 @@
+{
+  "[markdown][python]": {
+    "coc.preferences.formatOnSave": true
+  },
+  "python.analysis.autoSearchPaths": true,
+  "python.analysis.typeCheckingMode": "basic",
+  "python.analysis.useLibraryCodeForTypes": true,
+  "python.formatting.provider": "ruff",
+  "python.linting.ruffEnabled": true,
+  "python.linting.mypyEnabled": true,
+  "python.linting.flake8Enabled": false,
+  "python.linting.pyflakesEnabled": false,
+  "python.linting.pycodestyleEnabled": false,
+  "python.linting.banditEnabled": false,
+  "python.linting.pylamaEnabled": false,
+  "python.linting.pylintEnabled": false,
+  "pyright.organizeimports.provider": "ruff",
+  "pyright.testing.provider": "pytest",
+}
diff --git a/.vim/coc-settings.json b/.vim/coc-settings.json
new file mode 100644
index 0000000..d542a72
--- /dev/null
+++ b/.vim/coc-settings.json
@@ -0,0 +1,19 @@
+{
+  "[markdown][python]": {
+    "coc.preferences.formatOnSave": true
+  },
+  "python.analysis.autoSearchPaths": true,
+  "python.analysis.typeCheckingMode": "basic",
+  "python.analysis.useLibraryCodeForTypes": true,
+  "python.formatting.provider": "ruff",
+  "python.linting.ruffEnabled": true,
+  "python.linting.mypyEnabled": true,
+  "python.linting.flake8Enabled": false,
+  "python.linting.pyflakesEnabled": false,
+  "python.linting.pycodestyleEnabled": false,
+  "python.linting.banditEnabled": false,
+  "python.linting.pylamaEnabled": false,
+  "python.linting.pylintEnabled": false,
+  "pyright.organizeimports.provider": "ruff",
+  "pyright.testing.provider": "pytest",
+}
diff --git a/CHANGES b/CHANGES
index 7a0abbe..63087af 100644
--- a/CHANGES
+++ b/CHANGES
@@ -36,6 +36,13 @@ $ pipx install --suffix=@next g --pip-args '\--pre' --force
   This change replaces isort, flake8 and flake8 plugins.
 
   - Add additional ruff linters in #11
+  - Move from black to [`ruff format`] (#17)
+
+    This retains the same formatting style of `black` while eliminating a
+    dev dependency by using our existing rust-based `ruff` linter.
+
+    [`ruff format`]: https://docs.astral.sh/ruff/formatter/
+
 - poetry: 1.4.0 -> 1.5.0
 
   See also: https://github.com/python-poetry/poetry/releases/tag/1.5.0
diff --git a/Makefile b/Makefile
index 8276bbf..3b4ce97 100644
--- a/Makefile
+++ b/Makefile
@@ -29,8 +29,8 @@ start_docs:
 design_docs:
 	$(MAKE) -C docs design
 
-black:
-	poetry run black `${PY_FILES}`
+ruff_format:
+	poetry run ruff format .
 
 ruff:
 	ruff .
diff --git a/docs/developing.md b/docs/developing.md
index 45e5906..54710d1 100644
--- a/docs/developing.md
+++ b/docs/developing.md
@@ -48,22 +48,22 @@ Rebuild docs and run server via one terminal: `make dev_docs` (requires above, a
 
 ## Formatting / Linting
 
-### black
+### ruff
 
-[black] is used for formatting.
+The project uses [ruff] to handles formatting, sorting imports and linting.
 
 ````{tab} Command
 
 poetry:
 
 ```console
-$ poetry run black .
+$ poetry run ruff
 ```
 
 If you setup manually:
 
 ```console
-$ black .
+$ ruff .
 ```
 
 ````
@@ -71,63 +71,61 @@ $ black .
 ````{tab} make
 
 ```console
-$ make black
+$ make ruff
 ```
 
 ````
 
-In the future, `ruff` (below) may replace black as formatter.
+````{tab} Watch
 
-### ruff
+```console
+$ make watch_ruff
+```
 
-The project uses [ruff] to handles formatting, sorting imports and linting.
+requires [`entr(1)`].
 
-````{tab} Command
+````
+
+````{tab} Fix files
 
 poetry:
 
 ```console
-$ poetry run ruff
+$ poetry run ruff . --fix
 ```
 
 If you setup manually:
 
 ```console
-$ ruff .
+$ ruff . --fix
 ```
 
 ````
 
-````{tab} make
+#### ruff format
 
-```console
-$ make ruff
-```
+[ruff format] is used for formatting.
 
-````
+````{tab} Command
 
-````{tab} Watch
+poetry:
 
 ```console
-$ make watch_ruff
+$ poetry run ruff format .
 ```
 
-requires [`entr(1)`].
-
-````
-
-````{tab} Fix files
-
-poetry:
+If you setup manually:
 
 ```console
-$ poetry run ruff . --fix
+$ ruff format .
 ```
 
-If you setup manually:
+````
+
+````{tab} make
 
 ```console
-$ ruff . --fix
+$ make ruff_format
 ```
 
 ````
@@ -186,6 +184,6 @@ Update `__version__` in `__about__.py` and `pyproject.toml`::
 [poetry]: https://python-poetry.org/
 [entr(1)]: http://eradman.com/entrproject/
 [`entr(1)`]: http://eradman.com/entrproject/
-[black]: https://github.com/psf/black
+[ruff format]: https://docs.astral.sh/ruff/formatter/
 [ruff]: https://ruff.rs
 [mypy]: http://mypy-lang.org/
diff --git a/poetry.lock b/poetry.lock
index 1e0a6d3..73250c2 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -47,48 +47,6 @@ soupsieve = ">1.2"
 html5lib = ["html5lib"]
 lxml = ["lxml"]
 
-[[package]]
-name = "black"
-version = "23.11.0"
-description = "The uncompromising code formatter."
-optional = false
-python-versions = ">=3.8"
-files = [
-    {file = "black-23.11.0-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:dbea0bb8575c6b6303cc65017b46351dc5953eea5c0a59d7b7e3a2d2f433a911"},
-    {file = "black-23.11.0-cp310-cp310-macosx_11_0_arm64.whl", hash = "sha256:412f56bab20ac85927f3a959230331de5614aecda1ede14b373083f62ec24e6f"},
-    {file = "black-23.11.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:d136ef5b418c81660ad847efe0e55c58c8208b77a57a28a503a5f345ccf01394"},
-    {file = "black-23.11.0-cp310-cp310-win_amd64.whl", hash = "sha256:6c1cac07e64433f646a9a838cdc00c9768b3c362805afc3fce341af0e6a9ae9f"},
-    {file = "black-23.11.0-cp311-cp311-macosx_10_9_x86_64.whl", hash = "sha256:cf57719e581cfd48c4efe28543fea3d139c6b6f1238b3f0102a9c73992cbb479"},
-    {file = "black-23.11.0-cp311-cp311-macosx_11_0_arm64.whl", hash = "sha256:698c1e0d5c43354ec5d6f4d914d0d553a9ada56c85415700b81dc90125aac244"},
-    {file = "black-23.11.0-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:760415ccc20f9e8747084169110ef75d545f3b0932ee21368f63ac0fee86b221"},
-    {file = "black-23.11.0-cp311-cp311-win_amd64.whl", hash = "sha256:58e5f4d08a205b11800332920e285bd25e1a75c54953e05502052738fe16b3b5"},
-    {file = "black-23.11.0-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:45aa1d4675964946e53ab81aeec7a37613c1cb71647b5394779e6efb79d6d187"},
-    {file = "black-23.11.0-cp38-cp38-macosx_11_0_arm64.whl", hash = "sha256:4c44b7211a3a0570cc097e81135faa5f261264f4dfaa22bd5ee2875a4e773bd6"},
-    {file = "black-23.11.0-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:2a9acad1451632021ee0d146c8765782a0c3846e0e0ea46659d7c4f89d9b212b"},
-    {file = "black-23.11.0-cp38-cp38-win_amd64.whl", hash = "sha256:fc7f6a44d52747e65a02558e1d807c82df1d66ffa80a601862040a43ec2e3142"},
-    {file = "black-23.11.0-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:7f622b6822f02bfaf2a5cd31fdb7cd86fcf33dab6ced5185c35f5db98260b055"},
-    {file = "black-23.11.0-cp39-cp39-macosx_11_0_arm64.whl", hash = "sha256:250d7e60f323fcfc8ea6c800d5eba12f7967400eb6c2d21ae85ad31c204fb1f4"},
-    {file = "black-23.11.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:5133f5507007ba08d8b7b263c7aa0f931af5ba88a29beacc4b2dc23fcefe9c06"},
-    {file = "black-23.11.0-cp39-cp39-win_amd64.whl", hash = "sha256:421f3e44aa67138ab1b9bfbc22ee3780b22fa5b291e4db8ab7eee95200726b07"},
-    {file = "black-23.11.0-py3-none-any.whl", hash = "sha256:54caaa703227c6e0c87b76326d0862184729a69b73d3b7305b6288e1d830067e"},
-    {file = "black-23.11.0.tar.gz", hash = "sha256:4c68855825ff432d197229846f971bc4d6666ce90492e5b02013bcaca4d9ab05"},
-]
-
-[package.dependencies]
-click = ">=8.0.0"
-mypy-extensions = ">=0.4.3"
-packaging = ">=22.0"
-pathspec = ">=0.9.0"
-platformdirs = ">=2"
-tomli = {version = ">=1.1.0", markers = "python_version < \"3.11\""}
-typing-extensions = {version = ">=4.0.1", markers = "python_version < \"3.11\""}
-
-[package.extras]
-colorama = ["colorama (>=0.4.3)"]
-d = ["aiohttp (>=3.7.4)"]
-jupyter = ["ipython (>=7.8.0)", "tokenize-rt (>=3.2.0)"]
-uvloop = ["uvloop (>=0.15.2)"]
-
 [[package]]
 name = "certifi"
 version = "2023.11.17"
@@ -199,20 +157,6 @@ files = [
     {file = "charset_normalizer-3.3.2-py3-none-any.whl", hash = "sha256:3e4d1f6587322d2788836a99c69062fbb091331ec940e02d12d179c1d53e25fc"},
 ]
 
-[[package]]
-name = "click"
-version = "8.1.7"
-description = "Composable command line interface toolkit"
-optional = false
-python-versions = ">=3.7"
-files = [
-    {file = "click-8.1.7-py3-none-any.whl", hash = "sha256:ae74fb96c20a0277a1d615f1e4d73c8414f5a98db8b799a7931d1582f3390c28"},
-    {file = "click-8.1.7.tar.gz", hash = "sha256:ca9853ad459e787e2192211578cc907e7594e294c7ccc834310722b41b9ca6de"},
-]
-
-[package.dependencies]
-colorama = {version = "*", markers = "platform_system == \"Windows\""}
-
 [[package]]
 name = "codecov"
 version = "2.1.13"
@@ -665,32 +609,6 @@ files = [
     {file = "packaging-23.2.tar.gz", hash = "sha256:048fb0e9405036518eaaf48a55953c750c11e1a1b68e0dd1a9d62ed0c092cfc5"},
 ]
 
-[[package]]
-name = "pathspec"
-version = "0.11.2"
-description = "Utility library for gitignore style pattern matching of file paths."
-optional = false
-python-versions = ">=3.7"
-files = [
-    {file = "pathspec-0.11.2-py3-none-any.whl", hash = "sha256:1d6ed233af05e679efb96b1851550ea95bbb64b7c490b0f5aa52996c11e92a20"},
-    {file = "pathspec-0.11.2.tar.gz", hash = "sha256:e0d8d0ac2f12da61956eb2306b69f9469b42f4deb0f3cb6ed47b9cce9996ced3"},
-]
-
-[[package]]
-name = "platformdirs"
-version = "4.0.0"
-description = "A small Python package for determining appropriate platform-specific dirs, e.g. a \"user data dir\"."
-optional = false
-python-versions = ">=3.7"
-files = [
-    {file = "platformdirs-4.0.0-py3-none-any.whl", hash = "sha256:118c954d7e949b35437270383a3f2531e99dd93cf7ce4dc8340d3356d30f173b"},
-    {file = "platformdirs-4.0.0.tar.gz", hash = "sha256:cb633b2bcf10c51af60beb0ab06d2f1d69064b43abf4c185ca6b28865f3f9731"},
-]
-
-[package.extras]
-docs = ["furo (>=2023.7.26)", "proselint (>=0.13)", "sphinx (>=7.1.1)", "sphinx-autodoc-typehints (>=1.24)"]
-test = ["appdirs (==1.4.4)", "covdefaults (>=2.3)", "pytest (>=7.4)", "pytest-cov (>=4.1)", "pytest-mock (>=3.11.1)"]
-
 [[package]]
 name = "pluggy"
 version = "1.3.0"
@@ -1320,4 +1238,4 @@ test = []
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.8"
-content-hash = "1aa49312bceeac5317b5fcd703bd91998efd5f1710c435e3a3e2bd555921f0b7"
+content-hash = "17509a9ca7e838c59e0761ef3dfaf2d1b143b48d4142a9844ae8e3cc2df3baa9"
diff --git a/pyproject.toml b/pyproject.toml
index 45ad08d..c6d0ff3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,7 +79,6 @@ coverage = "*"
 pytest-cov = "*"
 
 ### Lint ###
-black = "*"
 ruff = "*"
 mypy = "*"
 
@@ -99,7 +98,7 @@ docs = [
 ]
 test = ["pytest", "pytest-rerunfailures", "pytest-watcher"]
 coverage = ["codecov", "coverage", "pytest-cov"]
-lint = ["black", "ruff", "mypy"]
+lint = ["ruff", "mypy"]
 
 [tool.mypy]
 strict = true
diff --git a/src/g/__init__.py b/src/g/__init__.py
index b068463..d913f76 100755
--- a/src/g/__init__.py
+++ b/src/g/__init__.py
@@ -26,7 +26,7 @@ def run(
     cmd_args: object = DEFAULT,
     wait: bool = False,
     *args: object,
-    **kwargs: t.Any
+    **kwargs: t.Any,
 ) -> t.Optional["subprocess.Popen[str]"]:
     # Interpret default kwargs lazily for mockability of argv
     if cmd is DEFAULT: