diff --git a/nix/packages.nix b/nix/packages.nix
index eb50d4a17..8795e35c8 100644
--- a/nix/packages.nix
+++ b/nix/packages.nix
@@ -1,54 +1,105 @@
 # nix/packages.nix — Hermes Agent package built with uv2nix
-{ inputs, ... }: {
-  perSystem = { pkgs, system, ... }:
+{ inputs, ... }:
+{
+  perSystem =
+    { pkgs, ... }:
     let
       hermesVenv = pkgs.callPackage ./python.nix {
         inherit (inputs) uv2nix pyproject-nix pyproject-build-systems;
       };
 
+      hermesTui = pkgs.callPackage ./tui.nix { };
+
       # Import bundled skills, excluding runtime caches
       bundledSkills = pkgs.lib.cleanSourceWith {
         src = ../skills;
-        filter = path: _type:
-          !(pkgs.lib.hasInfix "/index-cache/" path);
+        filter = path: _type: !(pkgs.lib.hasInfix "/index-cache/" path);
       };
 
       runtimeDeps = with pkgs; [
-        nodejs_20 ripgrep git openssh ffmpeg tirith
+        nodejs_22
+        ripgrep
+        git
+        openssh
+        ffmpeg
+        tirith
       ];
 
       runtimePath = pkgs.lib.makeBinPath runtimeDeps;
-    in {
-      packages.default = pkgs.stdenv.mkDerivation {
-        pname = "hermes-agent";
-        version = (builtins.fromTOML (builtins.readFile ../pyproject.toml)).project.version;
 
-        dontUnpack = true;
-        dontBuild = true;
-        nativeBuildInputs = [ pkgs.makeWrapper ];
+      # Lockfile hashes for dev shell stamps
+      pyprojectHash = builtins.hashString "sha256" (builtins.readFile ../pyproject.toml);
+      uvLockHash =
+        if builtins.pathExists ../uv.lock then
+          builtins.hashString "sha256" (builtins.readFile ../uv.lock)
+        else
+          "none";
+    in
+    {
+      packages = {
+        default = pkgs.stdenv.mkDerivation {
+          pname = "hermes-agent";
+          version = (fromTOML (builtins.readFile ../pyproject.toml)).project.version;
 
-        installPhase = ''
-          runHook preInstall
+          dontUnpack = true;
+          dontBuild = true;
+          nativeBuildInputs = [ pkgs.makeWrapper ];
 
-          mkdir -p $out/share/hermes-agent $out/bin
-          cp -r ${bundledSkills} $out/share/hermes-agent/skills
+          installPhase = ''
+            runHook preInstall
 
-          ${pkgs.lib.concatMapStringsSep "\n" (name: ''
-            makeWrapper ${hermesVenv}/bin/${name} $out/bin/${name} \
-              --suffix PATH : "${runtimePath}" \
-              --set HERMES_BUNDLED_SKILLS $out/share/hermes-agent/skills
-          '') [ "hermes" "hermes-agent" "hermes-acp" ]}
+            mkdir -p $out/share/hermes-agent $out/bin
+            cp -r ${bundledSkills} $out/share/hermes-agent/skills
 
-          runHook postInstall
-        '';
+            # copy pre-built TUI (same layout as dev: ui-tui/dist/ + node_modules/)
+            mkdir -p $out/ui-tui
+            cp -r ${hermesTui}/lib/hermes-tui/* $out/ui-tui/
 
-        meta = with pkgs.lib; {
-          description = "AI agent with advanced tool-calling capabilities";
-          homepage = "https://github.com/NousResearch/hermes-agent";
-          mainProgram = "hermes";
-          license = licenses.mit;
-          platforms = platforms.unix;
+            ${pkgs.lib.concatMapStringsSep "\n"
+              (name: ''
+              makeWrapper ${hermesVenv}/bin/${name} $out/bin/${name} \
+                --suffix PATH : "${runtimePath}" \
+                --set HERMES_BUNDLED_SKILLS $out/share/hermes-agent/skills \
+                --set HERMES_TUI_DIR $out/ui-tui \
+                --set HERMES_PYTHON ${hermesVenv}/bin/python3
+              '')
+              [
+                "hermes"
+                "hermes-agent"
+                "hermes-acp"
+              ]
+            }
+
+            runHook postInstall
+          '';
+
+          passthru.devShellHook = ''
+            STAMP=".nix-stamps/hermes-agent"
+            STAMP_VALUE="${pyprojectHash}:${uvLockHash}"
+            if [ ! -f "$STAMP" ] || [ "$(cat "$STAMP")" != "$STAMP_VALUE" ]; then
+              echo "hermes-agent: installing Python dependencies..."
+              uv venv .venv --python ${pkgs.python311}/bin/python3 2>/dev/null || true
+              source .venv/bin/activate
+              uv pip install -e ".[all]"
+              [ -d mini-swe-agent ] && uv pip install -e ./mini-swe-agent 2>/dev/null || true
+              [ -d tinker-atropos ] && uv pip install -e ./tinker-atropos 2>/dev/null || true
+              mkdir -p .nix-stamps
+              echo "$STAMP_VALUE" > "$STAMP"
+            else
+              source .venv/bin/activate
+            fi
+          '';
+
+          meta = with pkgs.lib; {
+            description = "AI agent with advanced tool-calling capabilities";
+            homepage = "https://github.com/NousResearch/hermes-agent";
+            mainProgram = "hermes";
+            license = licenses.mit;
+            platforms = platforms.unix;
+          };
         };
+
+        tui = hermesTui;
       };
     };
 }