diff --git a/action.yml b/action.yml
new file mode 100644
index 0000000..dff8102
--- /dev/null
+++ b/action.yml
@@ -0,0 +1,98 @@
+name: Export Godot project
+description: Download and cache Godot 4, install export templates, and export a named preset without Docker.
+
+inputs:
+  godot-version:
+    description: Exact Godot 4 release tag without a leading v (for example, 4.6.1-stable).
+    required: true
+  host-os:
+    description: "Runner operating system: linux, macos, or windows."
+    required: true
+  host-arch:
+    description: Runner architecture. Supported values depend on host-os.
+    required: true
+  dotnet:
+    description: Download the Godot .NET editor and export templates.
+    required: false
+    default: "false"
+  project-path:
+    description: Godot project directory, relative to the checked-out workspace.
+    required: false
+    default: .
+  export-preset:
+    description: Exact export preset name from export_presets.cfg.
+    required: true
+  export-mode:
+    description: "Export mode: release or debug."
+    required: false
+    default: release
+  export-file-name:
+    description: Output filename only, including its platform-appropriate extension.
+    required: true
+  cache:
+    description: Restore and save the downloaded Godot editor and export templates.
+    required: false
+    default: "true"
+
+outputs:
+  build-directory:
+    description: Absolute directory containing this invocation's exported build.
+    value: ${{ steps.export-linux.outputs.build-directory || steps.export-macos.outputs.build-directory || steps.export-windows.outputs.build-directory }}
+
+runs:
+  using: composite
+  steps:
+    - name: Restore Godot cache
+      if: ${{ inputs.cache == 'true' }}
+      uses: actions/cache@v4.1.0
+      with:
+        path: "${{ runner.temp }}/godot-export-action/cache"
+        key: "godot-export-action-v1-${{ inputs.godot-version }}-${{ inputs.dotnet }}-${{ inputs.host-os }}-${{ inputs.host-arch }}"
+
+    - name: Export Godot project on Linux
+      id: export-linux
+      if: ${{ runner.os == 'Linux' }}
+      shell: bash
+      env:
+        GODOT_VERSION: "${{ inputs.godot-version }}"
+        GODOT_HOST_OS: "${{ inputs.host-os }}"
+        GODOT_HOST_ARCH: "${{ inputs.host-arch }}"
+        GODOT_DOTNET: "${{ inputs.dotnet }}"
+        GODOT_PROJECT_PATH: "${{ inputs.project-path }}"
+        GODOT_EXPORT_PRESET: "${{ inputs.export-preset }}"
+        GODOT_EXPORT_MODE: "${{ inputs.export-mode }}"
+        GODOT_EXPORT_FILE_NAME: "${{ inputs.export-file-name }}"
+        GODOT_ACTION_ROOT: "${{ runner.temp }}/godot-export-action"
+      run: bash "$GITHUB_ACTION_PATH/export-linux.sh"
+
+    - name: Export Godot project on macOS
+      id: export-macos
+      if: ${{ runner.os == 'macOS' }}
+      shell: bash
+      env:
+        GODOT_VERSION: "${{ inputs.godot-version }}"
+        GODOT_HOST_OS: "${{ inputs.host-os }}"
+        GODOT_HOST_ARCH: "${{ inputs.host-arch }}"
+        GODOT_DOTNET: "${{ inputs.dotnet }}"
+        GODOT_PROJECT_PATH: "${{ inputs.project-path }}"
+        GODOT_EXPORT_PRESET: "${{ inputs.export-preset }}"
+        GODOT_EXPORT_MODE: "${{ inputs.export-mode }}"
+        GODOT_EXPORT_FILE_NAME: "${{ inputs.export-file-name }}"
+        GODOT_ACTION_ROOT: "${{ runner.temp }}/godot-export-action"
+      run: bash "$GITHUB_ACTION_PATH/export-macos.sh"
+
+    - name: Export Godot project on Windows
+      id: export-windows
+      if: ${{ runner.os == 'Windows' }}
+      shell: powershell
+      env:
+        GODOT_VERSION: "${{ inputs.godot-version }}"
+        GODOT_HOST_OS: "${{ inputs.host-os }}"
+        GODOT_HOST_ARCH: "${{ inputs.host-arch }}"
+        GODOT_DOTNET: "${{ inputs.dotnet }}"
+        GODOT_PROJECT_PATH: "${{ inputs.project-path }}"
+        GODOT_EXPORT_PRESET: "${{ inputs.export-preset }}"
+        GODOT_EXPORT_MODE: "${{ inputs.export-mode }}"
+        GODOT_EXPORT_FILE_NAME: "${{ inputs.export-file-name }}"
+        GODOT_ACTION_ROOT: "${{ runner.temp }}/godot-export-action"
+      run: "& \"$env:GITHUB_ACTION_PATH\\export-windows.ps1\""
diff --git a/export-linux.sh b/export-linux.sh
new file mode 100644
index 0000000..9214930
--- /dev/null
+++ b/export-linux.sh
@@ -0,0 +1,143 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+fail() {
+  echo "::error::$*" >&2
+  exit 1
+}
+
+require_command() {
+  command -v "$1" >/dev/null 2>&1 || fail "Required command '$1' was not found on the runner."
+}
+
+require_environment() {
+  [[ -n "${!1:-}" ]] || fail "Required environment variable '$1' is not set."
+}
+
+validate_common_inputs() {
+  [[ "$GODOT_VERSION" =~ ^4(\.[0-9]+){1,2}(-[0-9A-Za-z][0-9A-Za-z._-]*)?$ ]] || fail "godot-version must be a Godot 4 release tag such as 4.7.2-stable."
+  [[ "$GODOT_HOST_OS" == "linux" ]] || fail "host-os must be 'linux' when this action runs on Linux."
+  [[ "$GODOT_DOTNET" == "true" || "$GODOT_DOTNET" == "false" ]] || fail "dotnet must be 'true' or 'false'."
+  [[ "$GODOT_EXPORT_MODE" == "release" || "$GODOT_EXPORT_MODE" == "debug" ]] || fail "export-mode must be 'release' or 'debug'."
+  [[ -n "$GODOT_EXPORT_PRESET" ]] || fail "export-preset must not be empty."
+  [[ -n "$GODOT_EXPORT_FILE_NAME" && "$GODOT_EXPORT_FILE_NAME" != "." && "$GODOT_EXPORT_FILE_NAME" != ".." ]] || fail "export-file-name must be a filename."
+  [[ "$GODOT_EXPORT_FILE_NAME" != */* && "$GODOT_EXPORT_FILE_NAME" != *\\* ]] || fail "export-file-name must not contain a path separator."
+}
+
+actual_architecture() {
+  case "$(uname -m)" in
+    x86_64|amd64) echo x86_64 ;;
+    i?86) echo x86_32 ;;
+    aarch64|arm64) echo arm64 ;;
+    armv7l|armv6l) echo arm32 ;;
+    *) fail "Unsupported Linux runner architecture: $(uname -m)." ;;
+  esac
+}
+
+download_and_verify() {
+  local asset="$1"
+  local destination="$2"
+  local sum_file="$3"
+  local expected
+  local actual
+
+  curl --fail --location --retry 3 --silent --show-error "$BASE_URL/$asset" --output "$destination"
+  expected="$(awk -v asset="$asset" '$2 == asset || $2 == "*" asset { print $1; exit }' "$sum_file")"
+  [[ -n "$expected" ]] || fail "Release checksum manifest does not contain $asset."
+  actual="$(sha512sum "$destination" | awk '{ print $1 }')"
+  [[ "$actual" == "$expected" ]] || fail "SHA-512 verification failed for $asset."
+}
+
+find_editor() {
+  find "$EDITOR_DIR" -maxdepth 3 -type f -name 'Godot*' -print -quit
+}
+
+install_godot() {
+  local sum_file="$CACHE_DIR/SHA512-SUMS.txt"
+  local editor_archive="$CACHE_DIR/$EDITOR_ASSET"
+  local templates_archive="$CACHE_DIR/$TEMPLATES_ASSET"
+
+  rm -rf "$CACHE_DIR"
+  mkdir -p "$EDITOR_DIR" "$TEMPLATE_DIR"
+  curl --fail --location --retry 3 --silent --show-error "$BASE_URL/SHA512-SUMS.txt" --output "$sum_file"
+  download_and_verify "$EDITOR_ASSET" "$editor_archive" "$sum_file"
+  download_and_verify "$TEMPLATES_ASSET" "$templates_archive" "$sum_file"
+  unzip -q "$editor_archive" -d "$EDITOR_DIR"
+  unzip -q "$templates_archive" -d "$TEMPLATE_DIR"
+  EDITOR_EXECUTABLE="$(find_editor)"
+  [[ -n "$EDITOR_EXECUTABLE" ]] || fail "The Godot editor archive did not contain an executable."
+  [[ -f "$TEMPLATE_DIR/version.txt" ]] || fail "The export-template archive did not contain version.txt."
+  printf 'release=%s\neditor=%s\ntemplates=%s\n' "$GODOT_VERSION" "$EDITOR_ASSET" "$TEMPLATES_ASSET" > "$CACHE_DIR/.complete"
+}
+
+require_environment GODOT_VERSION
+require_environment GODOT_HOST_OS
+require_environment GODOT_HOST_ARCH
+require_environment GODOT_DOTNET
+require_environment GODOT_PROJECT_PATH
+require_environment GODOT_EXPORT_PRESET
+require_environment GODOT_EXPORT_MODE
+require_environment GODOT_EXPORT_FILE_NAME
+require_environment GODOT_ACTION_ROOT
+require_environment GITHUB_WORKSPACE
+require_environment GITHUB_OUTPUT
+
+require_command curl
+require_command unzip
+require_command sha512sum
+validate_common_inputs
+
+[[ "$(uname -s)" == "Linux" ]] || fail "The Linux script was selected on a non-Linux runner."
+[[ "$GODOT_HOST_ARCH" == "x86_32" || "$GODOT_HOST_ARCH" == "x86_64" || "$GODOT_HOST_ARCH" == "arm32" || "$GODOT_HOST_ARCH" == "arm64" ]] || fail "Unsupported Linux host-arch '$GODOT_HOST_ARCH'."
+[[ "$GODOT_HOST_ARCH" == "$(actual_architecture)" ]] || fail "host-arch '$GODOT_HOST_ARCH' does not match this Linux runner ($(actual_architecture))."
+
+[[ "$GODOT_PROJECT_PATH" != /* && "$GODOT_PROJECT_PATH" != \\* ]] || fail "project-path must be relative to the checked-out workspace."
+WORKSPACE_DIR="$(cd "$GITHUB_WORKSPACE" && pwd -P)"
+PROJECT_DIR="$(cd "$WORKSPACE_DIR/$GODOT_PROJECT_PATH" 2>/dev/null && pwd -P)" || fail "project-path '$GODOT_PROJECT_PATH' does not exist."
+case "$PROJECT_DIR/" in
+  "$WORKSPACE_DIR/"*) ;;
+  *) fail "project-path must remain inside the checked-out workspace." ;;
+esac
+[[ -f "$PROJECT_DIR/project.godot" ]] || fail "No project.godot was found in project-path '$GODOT_PROJECT_PATH'."
+[[ -f "$PROJECT_DIR/export_presets.cfg" ]] || fail "No export_presets.cfg was found in project-path '$GODOT_PROJECT_PATH'."
+grep -Fq "name=\"$GODOT_EXPORT_PRESET\"" "$PROJECT_DIR/export_presets.cfg" || fail "Export preset '$GODOT_EXPORT_PRESET' was not found in export_presets.cfg."
+
+if [[ "$GODOT_DOTNET" == "true" ]]; then
+  EDITION=dotnet
+  EDITOR_ASSET="Godot_v${GODOT_VERSION}_mono_linux_${GODOT_HOST_ARCH}.zip"
+  TEMPLATES_ASSET="Godot_v${GODOT_VERSION}_mono_export_templates.tpz"
+else
+  EDITION=standard
+  EDITOR_ASSET="Godot_v${GODOT_VERSION}_linux.${GODOT_HOST_ARCH}.zip"
+  TEMPLATES_ASSET="Godot_v${GODOT_VERSION}_export_templates.tpz"
+fi
+
+BASE_URL="https://github.com/godotengine/godot-builds/releases/download/$GODOT_VERSION"
+TEMPLATE_VERSION="${GODOT_VERSION//-/.}"
+CACHE_DIR="$GODOT_ACTION_ROOT/cache/$GODOT_VERSION/$EDITION/linux-$GODOT_HOST_ARCH"
+EDITOR_DIR="$CACHE_DIR/editor"
+USER_DATA_DIR="$CACHE_DIR/user-data"
+TEMPLATE_DIR="$USER_DATA_DIR/godot/export_templates/$TEMPLATE_VERSION"
+
+if [[ -f "$CACHE_DIR/.complete" && -f "$TEMPLATE_DIR/version.txt" ]]; then
+  EDITOR_EXECUTABLE="$(find_editor || true)"
+else
+  EDITOR_EXECUTABLE=""
+fi
+if [[ -z "$EDITOR_EXECUTABLE" ]]; then
+  install_godot
+fi
+
+chmod +x "$EDITOR_EXECUTABLE"
+SAFE_PRESET="$(printf '%s' "$GODOT_EXPORT_PRESET" | tr -cs '[:alnum:]_.-' '_')"
+BUILD_DIR="$GODOT_ACTION_ROOT/builds/${SAFE_PRESET:-export}-$GODOT_EXPORT_MODE-$$"
+OUTPUT_FILE="$BUILD_DIR/$GODOT_EXPORT_FILE_NAME"
+mkdir -p "$BUILD_DIR"
+
+export XDG_DATA_HOME="$USER_DATA_DIR"
+export XDG_CONFIG_HOME="$CACHE_DIR/config"
+"$EDITOR_EXECUTABLE" --headless --path "$PROJECT_DIR" "--export-$GODOT_EXPORT_MODE" "$GODOT_EXPORT_PRESET" "$OUTPUT_FILE"
+[[ -e "$OUTPUT_FILE" ]] || fail "Godot completed without creating the expected output '$GODOT_EXPORT_FILE_NAME'."
+
+printf 'build-directory=%s\n' "$BUILD_DIR" >> "$GITHUB_OUTPUT"
diff --git a/export-macos.sh b/export-macos.sh
new file mode 100644
index 0000000..8e549f4
--- /dev/null
+++ b/export-macos.sh
@@ -0,0 +1,140 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+fail() {
+  echo "::error::$*" >&2
+  exit 1
+}
+
+require_command() {
+  command -v "$1" >/dev/null 2>&1 || fail "Required command '$1' was not found on the runner."
+}
+
+require_environment() {
+  [[ -n "${!1:-}" ]] || fail "Required environment variable '$1' is not set."
+}
+
+validate_common_inputs() {
+  [[ "$GODOT_VERSION" =~ ^4(\.[0-9]+){1,2}(-[0-9A-Za-z][0-9A-Za-z._-]*)?$ ]] || fail "godot-version must be a Godot 4 release tag such as 4.7.2-stable."
+  [[ "$GODOT_HOST_OS" == "macos" ]] || fail "host-os must be 'macos' when this action runs on macOS."
+  [[ "$GODOT_DOTNET" == "true" || "$GODOT_DOTNET" == "false" ]] || fail "dotnet must be 'true' or 'false'."
+  [[ "$GODOT_EXPORT_MODE" == "release" || "$GODOT_EXPORT_MODE" == "debug" ]] || fail "export-mode must be 'release' or 'debug'."
+  [[ -n "$GODOT_EXPORT_PRESET" ]] || fail "export-preset must not be empty."
+  [[ -n "$GODOT_EXPORT_FILE_NAME" && "$GODOT_EXPORT_FILE_NAME" != "." && "$GODOT_EXPORT_FILE_NAME" != ".." ]] || fail "export-file-name must be a filename."
+  [[ "$GODOT_EXPORT_FILE_NAME" != */* && "$GODOT_EXPORT_FILE_NAME" != *\\* ]] || fail "export-file-name must not contain a path separator."
+}
+
+actual_architecture() {
+  case "$(uname -m)" in
+    x86_64) echo x86_64 ;;
+    arm64) echo arm64 ;;
+    *) fail "Unsupported macOS runner architecture: $(uname -m)." ;;
+  esac
+}
+
+download_and_verify() {
+  local asset="$1"
+  local destination="$2"
+  local sum_file="$3"
+  local expected
+  local actual
+
+  curl --fail --location --retry 3 --silent --show-error "$BASE_URL/$asset" --output "$destination"
+  expected="$(awk -v asset="$asset" '$2 == asset || $2 == "*" asset { print $1; exit }' "$sum_file")"
+  [[ -n "$expected" ]] || fail "Release checksum manifest does not contain $asset."
+  actual="$(shasum -a 512 "$destination" | awk '{ print $1 }')"
+  [[ "$actual" == "$expected" ]] || fail "SHA-512 verification failed for $asset."
+}
+
+find_editor() {
+  find "$EDITOR_DIR" -type f -path '*.app/Contents/MacOS/*' -name 'Godot*' -print -quit
+}
+
+install_godot() {
+  local sum_file="$CACHE_DIR/SHA512-SUMS.txt"
+  local editor_archive="$CACHE_DIR/$EDITOR_ASSET"
+  local templates_archive="$CACHE_DIR/$TEMPLATES_ASSET"
+
+  rm -rf "$CACHE_DIR"
+  mkdir -p "$EDITOR_DIR" "$TEMPLATE_DIR"
+  curl --fail --location --retry 3 --silent --show-error "$BASE_URL/SHA512-SUMS.txt" --output "$sum_file"
+  download_and_verify "$EDITOR_ASSET" "$editor_archive" "$sum_file"
+  download_and_verify "$TEMPLATES_ASSET" "$templates_archive" "$sum_file"
+  unzip -q "$editor_archive" -d "$EDITOR_DIR"
+  unzip -q "$templates_archive" -d "$TEMPLATE_DIR"
+  EDITOR_EXECUTABLE="$(find_editor)"
+  [[ -n "$EDITOR_EXECUTABLE" ]] || fail "The Godot editor archive did not contain a macOS app executable."
+  [[ -f "$TEMPLATE_DIR/version.txt" ]] || fail "The export-template archive did not contain version.txt."
+  printf 'release=%s\neditor=%s\ntemplates=%s\n' "$GODOT_VERSION" "$EDITOR_ASSET" "$TEMPLATES_ASSET" > "$CACHE_DIR/.complete"
+}
+
+require_environment GODOT_VERSION
+require_environment GODOT_HOST_OS
+require_environment GODOT_HOST_ARCH
+require_environment GODOT_DOTNET
+require_environment GODOT_PROJECT_PATH
+require_environment GODOT_EXPORT_PRESET
+require_environment GODOT_EXPORT_MODE
+require_environment GODOT_EXPORT_FILE_NAME
+require_environment GODOT_ACTION_ROOT
+require_environment GITHUB_WORKSPACE
+require_environment GITHUB_OUTPUT
+
+require_command curl
+require_command unzip
+require_command shasum
+validate_common_inputs
+
+[[ "$(uname -s)" == "Darwin" ]] || fail "The macOS script was selected on a non-macOS runner."
+[[ "$GODOT_HOST_ARCH" == "x86_64" || "$GODOT_HOST_ARCH" == "arm64" ]] || fail "Unsupported macOS host-arch '$GODOT_HOST_ARCH'."
+[[ "$GODOT_HOST_ARCH" == "$(actual_architecture)" ]] || fail "host-arch '$GODOT_HOST_ARCH' does not match this macOS runner ($(actual_architecture))."
+
+[[ "$GODOT_PROJECT_PATH" != /* && "$GODOT_PROJECT_PATH" != \\* ]] || fail "project-path must be relative to the checked-out workspace."
+WORKSPACE_DIR="$(cd "$GITHUB_WORKSPACE" && pwd -P)"
+PROJECT_DIR="$(cd "$WORKSPACE_DIR/$GODOT_PROJECT_PATH" 2>/dev/null && pwd -P)" || fail "project-path '$GODOT_PROJECT_PATH' does not exist."
+case "$PROJECT_DIR/" in
+  "$WORKSPACE_DIR/"*) ;;
+  *) fail "project-path must remain inside the checked-out workspace." ;;
+esac
+[[ -f "$PROJECT_DIR/project.godot" ]] || fail "No project.godot was found in project-path '$GODOT_PROJECT_PATH'."
+[[ -f "$PROJECT_DIR/export_presets.cfg" ]] || fail "No export_presets.cfg was found in project-path '$GODOT_PROJECT_PATH'."
+grep -Fq "name=\"$GODOT_EXPORT_PRESET\"" "$PROJECT_DIR/export_presets.cfg" || fail "Export preset '$GODOT_EXPORT_PRESET' was not found in export_presets.cfg."
+
+if [[ "$GODOT_DOTNET" == "true" ]]; then
+  EDITION=dotnet
+  EDITOR_ASSET="Godot_v${GODOT_VERSION}_mono_macos.universal.zip"
+  TEMPLATES_ASSET="Godot_v${GODOT_VERSION}_mono_export_templates.tpz"
+else
+  EDITION=standard
+  EDITOR_ASSET="Godot_v${GODOT_VERSION}_macos.universal.zip"
+  TEMPLATES_ASSET="Godot_v${GODOT_VERSION}_export_templates.tpz"
+fi
+
+BASE_URL="https://github.com/godotengine/godot-builds/releases/download/$GODOT_VERSION"
+TEMPLATE_VERSION="${GODOT_VERSION//-/.}"
+CACHE_DIR="$GODOT_ACTION_ROOT/cache/$GODOT_VERSION/$EDITION/macos-$GODOT_HOST_ARCH"
+EDITOR_DIR="$CACHE_DIR/editor"
+USER_HOME="$CACHE_DIR/home"
+TEMPLATE_DIR="$USER_HOME/Library/Application Support/Godot/export_templates/$TEMPLATE_VERSION"
+
+if [[ -f "$CACHE_DIR/.complete" && -f "$TEMPLATE_DIR/version.txt" ]]; then
+  EDITOR_EXECUTABLE="$(find_editor || true)"
+else
+  EDITOR_EXECUTABLE=""
+fi
+if [[ -z "$EDITOR_EXECUTABLE" ]]; then
+  install_godot
+fi
+
+chmod +x "$EDITOR_EXECUTABLE"
+SAFE_PRESET="$(printf '%s' "$GODOT_EXPORT_PRESET" | tr -cs '[:alnum:]_.-' '_')"
+BUILD_DIR="$GODOT_ACTION_ROOT/builds/${SAFE_PRESET:-export}-$GODOT_EXPORT_MODE-$$"
+OUTPUT_FILE="$BUILD_DIR/$GODOT_EXPORT_FILE_NAME"
+mkdir -p "$BUILD_DIR"
+
+export HOME="$USER_HOME"
+"$EDITOR_EXECUTABLE" --headless --path "$PROJECT_DIR" "--export-$GODOT_EXPORT_MODE" "$GODOT_EXPORT_PRESET" "$OUTPUT_FILE"
+[[ -e "$OUTPUT_FILE" ]] || fail "Godot completed without creating the expected output '$GODOT_EXPORT_FILE_NAME'."
+
+printf 'build-directory=%s\n' "$BUILD_DIR" >> "$GITHUB_OUTPUT"
diff --git a/export-windows.ps1 b/export-windows.ps1
new file mode 100644
index 0000000..6ae13f5
--- /dev/null
+++ b/export-windows.ps1
@@ -0,0 +1,152 @@
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+function Fail([string]$Message) {
+    Write-Error "::error::$Message"
+    exit 1
+}
+
+function Require-Environment([string]$Name) {
+    $value = [Environment]::GetEnvironmentVariable($Name)
+    if ([string]::IsNullOrWhiteSpace($value)) {
+        Fail "Required environment variable '$Name' is not set."
+    }
+    return $value
+}
+
+function Get-ActualArchitecture {
+    $architecture = $env:PROCESSOR_ARCHITEW6432
+    if ([string]::IsNullOrWhiteSpace($architecture)) {
+        $architecture = $env:PROCESSOR_ARCHITECTURE
+    }
+    switch ($architecture.ToUpperInvariant()) {
+        'AMD64' { return 'x86_64' }
+        'X86' { return 'x86_32' }
+        'ARM64' { return 'arm64' }
+        default { Fail "Unsupported Windows runner architecture: $architecture." }
+    }
+}
+
+function Get-Checksum([string]$ManifestPath, [string]$Asset) {
+    $line = Get-Content -LiteralPath $ManifestPath | Where-Object {
+        $_ -match '^([0-9A-Fa-f]{128})\s+\*?(.+)$' -and $Matches[2] -eq $Asset
+    } | Select-Object -First 1
+    if (-not $line) {
+        Fail "Release checksum manifest does not contain $Asset."
+    }
+    return ($line -split '\s+')[0].ToLowerInvariant()
+}
+
+function Download-AndVerify([string]$Asset, [string]$Destination, [string]$ManifestPath) {
+    Invoke-WebRequest -Uri "$script:BaseUrl/$Asset" -OutFile $Destination
+    $expected = Get-Checksum $ManifestPath $Asset
+    $actual = (Get-FileHash -LiteralPath $Destination -Algorithm SHA512).Hash.ToLowerInvariant()
+    if ($actual -ne $expected) {
+        Fail "SHA-512 verification failed for $Asset."
+    }
+}
+
+function Find-Editor([string]$Directory) {
+    $console = Get-ChildItem -LiteralPath $Directory -Recurse -File -Filter 'Godot*console.exe' -ErrorAction SilentlyContinue | Select-Object -First 1
+    if ($console) { return $console.FullName }
+    $editor = Get-ChildItem -LiteralPath $Directory -Recurse -File -Filter 'Godot*.exe' -ErrorAction SilentlyContinue | Select-Object -First 1
+    if ($editor) { return $editor.FullName }
+    return $null
+}
+
+$GodotVersion = Require-Environment 'GODOT_VERSION'
+$HostOs = Require-Environment 'GODOT_HOST_OS'
+$HostArch = Require-Environment 'GODOT_HOST_ARCH'
+$Dotnet = Require-Environment 'GODOT_DOTNET'
+$ProjectPath = Require-Environment 'GODOT_PROJECT_PATH'
+$ExportPreset = Require-Environment 'GODOT_EXPORT_PRESET'
+$ExportMode = Require-Environment 'GODOT_EXPORT_MODE'
+$ExportFileName = Require-Environment 'GODOT_EXPORT_FILE_NAME'
+$ActionRoot = Require-Environment 'GODOT_ACTION_ROOT'
+$Workspace = Require-Environment 'GITHUB_WORKSPACE'
+$GithubOutput = Require-Environment 'GITHUB_OUTPUT'
+
+if ($GodotVersion -notmatch '^4(\.[0-9]+){1,2}(-[0-9A-Za-z][0-9A-Za-z._-]*)?$') { Fail 'godot-version must be a Godot 4 release tag such as 4.7.2-stable.' }
+if ($HostOs -ne 'windows') { Fail "host-os must be 'windows' when this action runs on Windows." }
+if ($Dotnet -notin @('true', 'false')) { Fail "dotnet must be 'true' or 'false'." }
+if ($ExportMode -notin @('release', 'debug')) { Fail "export-mode must be 'release' or 'debug'." }
+if ([string]::IsNullOrWhiteSpace($ExportPreset)) { Fail 'export-preset must not be empty.' }
+if ([string]::IsNullOrWhiteSpace($ExportFileName) -or $ExportFileName -in @('.', '..') -or $ExportFileName.IndexOfAny([IO.Path]::GetInvalidFileNameChars()) -ge 0 -or $ExportFileName.Contains('/') -or $ExportFileName.Contains('\')) { Fail 'export-file-name must be a filename without path separators.' }
+if ($HostArch -notin @('x86_32', 'x86_64', 'arm64')) { Fail "Unsupported Windows host-arch '$HostArch'." }
+if ($HostArch -ne (Get-ActualArchitecture)) { Fail "host-arch '$HostArch' does not match this Windows runner ($(Get-ActualArchitecture))." }
+
+$workspaceDirectory = [IO.Path]::GetFullPath($Workspace)
+if ([IO.Path]::IsPathRooted($ProjectPath)) { Fail 'project-path must be relative to the checked-out workspace.' }
+$ProjectDirectory = [IO.Path]::GetFullPath((Join-Path $workspaceDirectory $ProjectPath))
+$projectRelativePath = [IO.Path]::GetRelativePath($workspaceDirectory, $ProjectDirectory)
+if ($projectRelativePath -eq '..' -or $projectRelativePath.StartsWith("..$([IO.Path]::DirectorySeparatorChar)") -or [IO.Path]::IsPathRooted($projectRelativePath)) { Fail 'project-path must remain inside the checked-out workspace.' }
+if (-not (Test-Path -LiteralPath (Join-Path $ProjectDirectory 'project.godot') -PathType Leaf)) { Fail "No project.godot was found in project-path '$ProjectPath'." }
+$PresetFile = Join-Path $ProjectDirectory 'export_presets.cfg'
+if (-not (Test-Path -LiteralPath $PresetFile -PathType Leaf)) { Fail "No export_presets.cfg was found in project-path '$ProjectPath'." }
+if (-not (Select-String -LiteralPath $PresetFile -SimpleMatch "name=`"$ExportPreset`"" -Quiet)) { Fail "Export preset '$ExportPreset' was not found in export_presets.cfg." }
+
+if ($Dotnet -eq 'true') {
+    $edition = 'dotnet'
+    $editorAsset = switch ($HostArch) {
+        'x86_32' { "Godot_v${GodotVersion}_mono_win32.zip" }
+        'x86_64' { "Godot_v${GodotVersion}_mono_win64.zip" }
+        'arm64' { "Godot_v${GodotVersion}_mono_windows_arm64.zip" }
+    }
+    $templatesAsset = "Godot_v${GodotVersion}_mono_export_templates.tpz"
+} else {
+    $edition = 'standard'
+    $editorAsset = switch ($HostArch) {
+        'x86_32' { "Godot_v${GodotVersion}_win32.exe.zip" }
+        'x86_64' { "Godot_v${GodotVersion}_win64.exe.zip" }
+        'arm64' { "Godot_v${GodotVersion}_windows_arm64.exe.zip" }
+    }
+    $templatesAsset = "Godot_v${GodotVersion}_export_templates.tpz"
+}
+
+$script:BaseUrl = "https://github.com/godotengine/godot-builds/releases/download/$GodotVersion"
+$templateVersion = $GodotVersion -replace '-', '.'
+$cacheDirectory = Join-Path $ActionRoot "cache\$GodotVersion\$edition\windows-$HostArch"
+$editorDirectory = Join-Path $cacheDirectory 'editor'
+$userHome = Join-Path $cacheDirectory 'home'
+$templateDirectory = Join-Path $userHome "AppData\Roaming\Godot\export_templates\$templateVersion"
+$marker = Join-Path $cacheDirectory '.complete'
+
+$editorExecutable = $null
+if ((Test-Path -LiteralPath $marker -PathType Leaf) -and (Test-Path -LiteralPath (Join-Path $templateDirectory 'version.txt') -PathType Leaf)) {
+    $editorExecutable = Find-Editor $editorDirectory
+}
+
+if (-not $editorExecutable) {
+    if (Test-Path -LiteralPath $cacheDirectory) { Remove-Item -LiteralPath $cacheDirectory -Recurse -Force }
+    New-Item -ItemType Directory -Force -Path $editorDirectory, $templateDirectory | Out-Null
+    $manifestPath = Join-Path $cacheDirectory 'SHA512-SUMS.txt'
+    $editorArchive = Join-Path $cacheDirectory $editorAsset
+    $templatesArchive = Join-Path $cacheDirectory $templatesAsset
+    Invoke-WebRequest -Uri "$script:BaseUrl/SHA512-SUMS.txt" -OutFile $manifestPath
+    Download-AndVerify $editorAsset $editorArchive $manifestPath
+    Download-AndVerify $templatesAsset $templatesArchive $manifestPath
+    Expand-Archive -LiteralPath $editorArchive -DestinationPath $editorDirectory -Force
+    Expand-Archive -LiteralPath $templatesArchive -DestinationPath $templateDirectory -Force
+    $editorExecutable = Find-Editor $editorDirectory
+    if (-not $editorExecutable) { Fail 'The Godot editor archive did not contain an executable.' }
+    if (-not (Test-Path -LiteralPath (Join-Path $templateDirectory 'version.txt') -PathType Leaf)) { Fail 'The export-template archive did not contain version.txt.' }
+    @("release=$GodotVersion", "editor=$editorAsset", "templates=$templatesAsset") | Set-Content -LiteralPath $marker -NoNewline
+}
+
+$safePreset = ($ExportPreset -replace '[^A-Za-z0-9_.-]', '_').Trim('_')
+if ([string]::IsNullOrWhiteSpace($safePreset)) { $safePreset = 'export' }
+$buildDirectory = Join-Path $ActionRoot "builds\$safePreset-$ExportMode-$PID"
+$outputFile = Join-Path $buildDirectory $ExportFileName
+New-Item -ItemType Directory -Force -Path $buildDirectory | Out-Null
+
+$env:USERPROFILE = $userHome
+$env:APPDATA = Join-Path $userHome 'AppData\Roaming'
+$env:LOCALAPPDATA = Join-Path $userHome 'AppData\Local'
+& $editorExecutable --headless --path $ProjectDirectory "--export-$ExportMode" $ExportPreset $outputFile
+if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+if (-not (Test-Path -LiteralPath $outputFile)) { Fail "Godot completed without creating the expected output '$ExportFileName'." }
+
+"build-directory=$buildDirectory" | Add-Content -LiteralPath $GithubOutput