diff --git a/.envrc b/.envrc
index f746973cae60..01232045f166 100644
--- a/.envrc
+++ b/.envrc
@@ -1,5 +1,5 @@
 watch_file pyproject.toml uv.lock
 watch_file package-lock.json package.json web/package.json ui-tui/package.json website/package.json apps/shared/package.json apps/desktop/package.json ui-tui/packages/hermes-ink/package.json
-watch_file flake.nix flake.lock nix/devShell.nix nix/tui.nix nix/package.nix nix/python.nix
+watch_file flake.nix flake.lock nix/devShell.nix nix/tui.nix nix/package.nix nix/python.nix nix/hermes-agent.nix nix/desktop.nix
 
 use flake
diff --git a/nix/devShell.nix b/nix/devShell.nix
index c131bbb5ba77..28fb380a913c 100644
--- a/nix/devShell.nix
+++ b/nix/devShell.nix
@@ -25,10 +25,12 @@
     in
     {
       devShells.default = pkgs.mkShell {
-        inputsFrom = packages;
-        packages = with pkgs; [
-          uv
-        ];
+        packages =
+          with pkgs;
+          [
+            uv
+          ]
+          ++ self'.packages.default.passthru.devDeps;
         shellHook = ''
           echo "Hermes Agent dev shell"
           ${combinedNonNpm}
diff --git a/nix/hermes-agent.nix b/nix/hermes-agent.nix
index 1dd3031fb948..3d7dc260f5e4 100644
--- a/nix/hermes-agent.nix
+++ b/nix/hermes-agent.nix
@@ -37,10 +37,14 @@
 }:
 let
   nodejs = nodejs_22;
-  hermesVenv = callPackage ./python.nix {
-    inherit uv2nix pyproject-nix pyproject-build-systems;
-    dependency-groups = [ "all" ] ++ extraDependencyGroups;
-  };
+  mkHermesVenv =
+    extraDependencyGroups:
+    callPackage ./python.nix {
+      inherit uv2nix pyproject-nix pyproject-build-systems;
+      dependency-groups = [ "all" ] ++ extraDependencyGroups;
+    };
+
+  hermesVenv = mkHermesVenv extraDependencyGroups;
 
   hermesNpmLib = callPackage ./lib.nix {
     inherit npm-lockfile-fix nodejs;
@@ -106,12 +110,6 @@ let
 
   pythonPath = lib.makeSearchPath sitePackagesPath allExtraPythonPackages;
 
-  pyprojectHash = builtins.hashString "sha256" (builtins.readFile ../pyproject.toml);
-  uvLockHash =
-    if builtins.pathExists ../uv.lock then
-      builtins.hashString "sha256" (builtins.readFile ../uv.lock)
-    else
-      "none";
   checkPackageCollisions = ''
     import pathlib, sys, re
 
@@ -223,21 +221,10 @@ stdenv.mkDerivation (finalAttrs: {
     };
 
     devShellHook = ''
-      STAMP=".nix-stamps/hermes-agent"
-      STAMP_VALUE="${pyprojectHash}:${uvLockHash}"
-      if [ ! -f "$STAMP" ] || [ "$(cat "$STAMP")" != "$STAMP_VALUE" ]; then
-        echo "hermes-agent: installing Python dependencies..."
-        uv venv .venv --python ${python312}/bin/python3 2>/dev/null || true
-        source .venv/bin/activate
-        uv pip install -e ".[all]"
-        [ -d mini-swe-agent ] && uv pip install -e ./mini-swe-agent 2>/dev/null || true
-        mkdir -p .nix-stamps
-        echo "$STAMP_VALUE" > "$STAMP"
-      else
-        source .venv/bin/activate
-        export HERMES_PYTHON=${hermesVenv}/bin/python3
-      fi
+      export HERMES_PYTHON=${hermesVenv}/bin/python3
     '';
+
+    devDeps = runtimeDeps ++ [ (mkHermesVenv (extraDependencyGroups ++ [ "dev" ])) ];
   };
 
   meta = with lib; {