diff --git a/flake.nix b/flake.nix
index 7faf50a5..05ee1fa1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -38,6 +38,10 @@
               bashInteractive
               bash-completion
 
+              # dev utils
+              ruff
+              pypkgs.ruff
+
               qt6.qtwayland
               qt6.qtbase
 
@@ -85,7 +89,7 @@
               # - always use the ./py313/ venv-subdir
               export UV_PROJECT_ENVIRONMENT="py313"
               # sync project-env with all extras
-              uv sync --dev --all-extras
+              uv sync --dev --all-extras --no-group lint
 
               # ------ TIPS ------
               # NOTE, to launch the py-venv installed `xonsh` (like @goodboy)
diff --git a/pyproject.toml b/pyproject.toml
index 0b72fdb2..6b130778 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -63,8 +63,6 @@ dependencies = [
     "trio-util >=0.7.0, <0.8.0",
     "trio-websocket >=0.10.3, <0.11.0",
     "typer >=0.9.0, <1.0.0",
-    "rapidfuzz >=3.5.2, <4.0.0",
-    "pdbp >=1.5.0, <2.0.0",
     "trio >=0.27",
     "pendulum",
     "httpx >=0.27.0, <0.28.0",
@@ -77,9 +75,13 @@ dependencies = [
     "trio-typing>=0.10.0",
     "numba>=0.61.0",
     "pyvnc",
+    # TODO? mv to dev group?
+    "pdbp >=1.5.0, <2.0.0",
 ]
+# ------ dependencies ------
 
-[project.optional-dependencies]
+
+[dependency-groups]
 uis = [
     # https://docs.astral.sh/uv/concepts/projects/dependencies/#optional-dependencies
     # TODO: make sure the levenshtein shit compiles on nix..
@@ -94,7 +96,6 @@ uis = [
     # https://docs.astral.sh/uv/concepts/projects/dependencies/#optional-dependencies
 ]
 
-[dependency-groups]
 # TODO: a toolset that makes debugging a `pikerd` service (tree) easy
 # to hack on directly using more or less the local env:
 # - xonsh + xxh
@@ -105,12 +106,11 @@ uis = [
 # use `uv --dev` to enable
 dev = [
     "pytest",
-    "elasticsearch >=8.9.0, <9.0.0",
     "prompt-toolkit ==3.0.40",
     "cython >=3.0.0, <4.0.0",
     "greenback >=1.1.1, <2.0.0",
-    "ruff>=0.9.6",
     "pyperclip>=1.9.0",
+    # DE-specific
     "i3ipc>=2.2.1",
 
     # ?from git, see below.
@@ -120,6 +120,19 @@ dev = [
     "pyqtgraph",
 
 ]
+lint = [
+  # XXX, with flake.nix needs to be from nixpkgs
+  "ruff>=0.9.6" 
+  #
+  # ^TODO? these markers don't work; use deps-flags for now?
+  # ; os_name != 'nixos' and platform_system != 'NixOS'",
+  # ; defined('IN_NIX_SHELL')",
+]
+dbs = [
+  "elasticsearch >=8.9.0, <9.0.0",
+]
+# ------ dependency-groups ------
+
 
 [tool.pytest.ini_options]
 # https://docs.pytest.org/en/stable/reference/reference.html#configuration-options
@@ -132,24 +145,29 @@ console_output_style = 'progress'
 # https://docs.pytest.org/en/stable/how-to/plugins.html#disabling-plugins-from-autoloading
 # https://docs.pytest.org/en/stable/how-to/plugins.html#deactivating-unregistering-a-plugin-by-name
 addopts = '-p no:xonsh'
+# ------ tool.pytest ------
 
 
 [project.scripts]
 piker = "piker.cli:cli"
 pikerd = "piker.cli:pikerd"
 ledger = "piker.accounting.cli:ledger"
+# ------ project.scripts ------
 
 [tool.hatch.build.targets.sdist]
 include = ["piker"]
-
 [tool.hatch.build.targets.wheel]
 include = ["piker"]
+# ------ tool.hatch ------
 
 
 # TODO? move to a `uv.toml`?
 [tool.uv]
 python-preference = 'system'
 python-downloads = 'manual'
+# https://docs.astral.sh/uv/concepts/projects/dependencies/#default-groups
+default-groups = ['uis', 'dev']
+# ------ tool.uv ------
 
 
 [tool.uv.sources]