diff --git a/kota_tech/__init__.py b/kota_tech/__init__.py
index 0b261f5..2f96e44 100644
--- a/kota_tech/__init__.py
+++ b/kota_tech/__init__.py
@@ -1,3 +1,3 @@
 """KOTA sensorbox technician tool."""
 
-__version__ = "0.8.0"
+__version__ = "0.9.0"
diff --git a/pyproject.toml b/pyproject.toml
index f8ec057..de52aac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "kota-technician-tool"
-version = "0.8.0"
+version = "0.9.0"
 description = "KOTA sensorbox technician diagnostic tool (demo)"
 requires-python = ">=3.11,<3.14"
 dependencies = [
diff --git a/run_macos.command b/run_macos.command
index 0a15bf5..029f753 100755
--- a/run_macos.command
+++ b/run_macos.command
@@ -4,8 +4,8 @@ cd "$(dirname "$0")" || exit 1
 
 # If Finder refuses to open this file (Google Drive drops the executable bit), run it once as:
 #   bash run_macos.command     (or: chmod +x run_macos.command)
-# Keep the virtual environment out of the (Google Drive) tool folder.
-export UV_PROJECT_ENVIRONMENT="$HOME/Library/Caches/KotaTechnicianTool/venv-0.8"
+# One shared Python environment for every version (update_macos.command keeps it current).
+export UV_PROJECT_ENVIRONMENT="$HOME/Library/Caches/KotaTechnicianTool/venv"
 export PATH="$HOME/.local/bin:$PATH"
 
 if ! command -v uv >/dev/null 2>&1; then
diff --git a/run_windows.bat b/run_windows.bat
index 180a59e..f4be0dc 100644
--- a/run_windows.bat
+++ b/run_windows.bat
@@ -2,8 +2,8 @@
 setlocal
 cd /d "%~dp0"
 
-rem Keep the virtual environment out of the (Google Drive) tool folder.
-set "UV_PROJECT_ENVIRONMENT=%LOCALAPPDATA%\KotaTechnicianTool\venv-0.8"
+rem One shared Python environment for every version (update_windows.bat keeps it current).
+set "UV_PROJECT_ENVIRONMENT=%LOCALAPPDATA%\KotaTechnicianTool\venv"
 set "PATH=%USERPROFILE%\.local\bin;%PATH%"
 
 where uv >nul 2>nul
diff --git a/update_macos.command b/update_macos.command
new file mode 100755
index 0000000..b014914
--- /dev/null
+++ b/update_macos.command
@@ -0,0 +1,74 @@
+#!/bin/bash
+# KOTA Sensorbox Technician Tool - update to the newest released version.
+# Checks Gitea for the newest release tag (vX.Y) and downloads only what changed (git).
+# Works in a git clone and in a folder unpacked from a release zip (it is connected on first run).
+# If Finder refuses to open this file, run it once as:  bash update_macos.command
+cd "$(dirname "$0")" || exit 1
+
+REPO_URL="${KOTA_REPO_URL:-https://gitea.kota-app.com/kkallas/kota-technician-tool.git}"
+export UV_PROJECT_ENVIRONMENT="${UV_PROJECT_ENVIRONMENT:-$HOME/Library/Caches/KotaTechnicianTool/venv}"
+export PATH="$HOME/.local/bin:$PATH"
+
+finish() {
+    [ -z "$KOTA_NO_PAUSE" ] && [ -t 0 ] && read -r -p "Press Enter to close..." _
+    exit "$1"
+}
+fail() { echo; echo "[!] $*"; echo "[!] Update did not finish."; finish 1; }
+
+# ---- git (macOS: the Command Line Tools installer offers it) --------------
+if ! git --version >/dev/null 2>&1; then
+    if [ "$(uname)" = Darwin ]; then
+        xcode-select --install >/dev/null 2>&1
+        fail "Git is being installed (Apple Command Line Tools). Run this again when the installer has finished."
+    fi
+    fail "Git is not installed."
+fi
+
+# ---- connect a folder unpacked from a zip ----------------------------------
+if [ ! -d .git ]; then
+    echo "Connecting this folder to $REPO_URL ..."
+    git init -q && git remote add origin "$REPO_URL" || fail "Cannot set up git in this folder."
+fi
+
+# A developer copy follows a branch; it is updated with "git pull", not here.
+if git rev-parse -q --verify HEAD >/dev/null 2>&1 && branch=$(git symbolic-ref -q --short HEAD); then
+    echo "This is a developer copy on branch $branch. Update it with: git pull"
+    finish 0
+fi
+
+echo "Checking for a new version..."
+git fetch --quiet --force --tags origin ||
+    fail "Cannot reach $REPO_URL. Check the Internet connection and your Gitea login, then try again."
+
+latest=$(git tag -l 'v*' --sort=-v:refname | head -n 1)
+[ -n "$latest" ] || fail "No released version found on the server."
+current=$(git describe --tags --exact-match HEAD 2>/dev/null)
+
+if [ "$current" = "$latest" ]; then
+    echo "You already have the newest version $latest."
+else
+    if [ -n "$current" ]; then
+        if [ -n "$(git status --porcelain --untracked-files=no)" ]; then
+            echo "Some tool files in this folder were changed by hand. They will be replaced by $latest."
+            read -r -p "Continue? [y/N] " answer
+            [[ "$answer" =~ ^[Yy]$ ]] || fail "Cancelled."
+        fi
+        echo "Updating $current -> $latest. Changes:"
+        git --no-pager log --oneline --no-decorate "$current..$latest"
+    else
+        echo "Installing $latest..."
+    fi
+    git -c advice.detachedHead=false checkout -q -f "$latest" || fail "Checkout of $latest failed."
+    echo "Now on $latest."
+fi
+
+# ---- Python libraries (only what changed) ----------------------------------
+if ! command -v uv >/dev/null 2>&1; then
+    echo "Installing uv (Python package runner, current user only)..."
+    curl -LsSf https://astral.sh/uv/install.sh | sh || fail "uv installation failed. Ask the firmware team for help."
+fi
+echo "Checking Python libraries..."
+uv sync --frozen --no-dev --python 3.12 --quiet || fail "Installing Python libraries failed."
+echo
+echo "Done. Start the tool with run_macos.command."
+finish 0
diff --git a/update_windows.bat b/update_windows.bat
new file mode 100644
index 0000000..e0de997
--- /dev/null
+++ b/update_windows.bat
@@ -0,0 +1,107 @@
+@echo off
+rem KOTA Sensorbox Technician Tool - update to the newest released version.
+rem Checks Gitea for the newest release tag (vX.Y) and downloads only what changed (git).
+rem Works in a git clone and in a folder unpacked from a release zip (it is connected on first run).
+setlocal EnableDelayedExpansion
+cd /d "%~dp0"
+title KOTA Technician Tool - update
+
+if not defined KOTA_REPO_URL set "KOTA_REPO_URL=https://gitea.kota-app.com/kkallas/kota-technician-tool.git"
+set "UV_PROJECT_ENVIRONMENT=%LOCALAPPDATA%\KotaTechnicianTool\venv"
+set "PATH=%USERPROFILE%\.local\bin;%ProgramFiles%\Git\cmd;%PATH%"
+
+rem ---- git ----------------------------------------------------------------
+where git >nul 2>nul
+if errorlevel 1 (
+    echo Git is not installed. It is needed to download updates.
+    choice /m "Install Git for Windows now"
+    if errorlevel 2 goto :fail
+    winget install --id Git.Git -e --source winget --accept-package-agreements
+    where git >nul 2>nul
+    if errorlevel 1 (
+        echo [!] Git installation failed. Install it from https://git-scm.com and run this again.
+        goto :fail
+    )
+)
+
+rem ---- connect a folder unpacked from a zip ---------------------------------
+if not exist ".git" (
+    echo Connecting this folder to %KOTA_REPO_URL% ...
+    git init -q || goto :fail
+    git remote add origin "%KOTA_REPO_URL%" || goto :fail
+)
+
+rem A developer copy follows a branch; it is updated with "git pull", not here.
+git rev-parse -q --verify HEAD >nul 2>nul
+if not errorlevel 1 (
+    for /f "delims=" %%b in ('git symbolic-ref -q --short HEAD 2^>nul') do (
+        echo This is a developer copy on branch %%b. Update it with: git pull
+        goto :done
+    )
+)
+
+echo Checking for a new version...
+git fetch --quiet --force --tags origin
+if errorlevel 1 (
+    echo [!] Cannot reach %KOTA_REPO_URL%.
+    echo     Check the Internet connection and your Gitea login, then try again.
+    goto :fail
+)
+
+set "LATEST="
+for /f "delims=" %%t in ('git tag -l "v*" --sort^=-v:refname') do if not defined LATEST set "LATEST=%%t"
+if not defined LATEST (
+    echo [!] No released version found on the server.
+    goto :fail
+)
+set "CURRENT="
+for /f "delims=" %%t in ('git describe --tags --exact-match HEAD 2^>nul') do set "CURRENT=%%t"
+
+if "%CURRENT%"=="%LATEST%" (
+    echo You already have the newest version %LATEST%.
+    goto :deps
+)
+
+if defined CURRENT (
+    for /f "delims=" %%s in ('git status --porcelain --untracked-files^=no') do set "DIRTY=1"
+    if defined DIRTY (
+        echo Some tool files in this folder were changed by hand. They will be replaced by %LATEST%.
+        choice /m "Continue"
+        if errorlevel 2 goto :fail
+    )
+    echo Updating %CURRENT% -^> %LATEST%. Changes:
+    git --no-pager log --oneline --no-decorate "%CURRENT%..%LATEST%"
+) else (
+    echo Installing %LATEST%...
+)
+git -c advice.detachedHead=false checkout -q -f "%LATEST%"
+if errorlevel 1 goto :fail
+echo Now on %LATEST%.
+
+rem ---- Python libraries (only what changed) ----------------------------------
+:deps
+where uv >nul 2>nul
+if errorlevel 1 (
+    echo Installing uv ^(Python package runner, current user only^)...
+    powershell -NoProfile -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
+)
+where uv >nul 2>nul
+if errorlevel 1 (
+    echo [!] uv installation failed. Ask the firmware team for help.
+    goto :fail
+)
+echo Checking Python libraries...
+uv sync --frozen --no-dev --python 3.12 --quiet
+if errorlevel 1 goto :fail
+echo.
+echo Done. Start the tool with run_windows.bat.
+
+:done
+if not defined KOTA_NO_PAUSE pause
+exit /b 0
+
+:fail
+echo.
+echo [!] Update did not finish.
+if not defined KOTA_NO_PAUSE pause
+exit /b 1
diff --git a/uv.lock b/uv.lock
index f56f5b6..098561d 100644
--- a/uv.lock
+++ b/uv.lock
@@ -250,7 +250,7 @@ wheels = [
 
 [[package]]
 name = "kota-technician-tool"
-version = "0.8.0"
+version = "0.9.0"
 source = { virtual = "." }
 dependencies = [
     { name = "esptool" },