diff --git a/macTEMTests/AppStoreReleaseTests.swift b/macTEMTests/AppStoreReleaseTests.swift
new file mode 100644
index 0000000..2e66c99
--- /dev/null
+++ b/macTEMTests/AppStoreReleaseTests.swift
@@ -0,0 +1,37 @@
+//
+//  AppStoreReleaseTests.swift
+//  One tag, two builds (macTEM#103): tools/release.sh builds the Developer ID DMG, tools/release-store.sh the App Store
+//  package. The export options and the script's guards are files a later edit can quietly break; these read them.
+//
+
+import XCTest
+
+nonisolated final class AppStoreReleaseTests: XCTestCase {
+    private let root = URL(fileURLWithPath: #filePath).resolvingSymlinksInPath().deletingLastPathComponent()
+        .deletingLastPathComponent()
+
+    /// Mutation: method back to "developer-id", destination "upload", or another team - red.
+    func testTheStoreExportOptionsExportAnAppStorePackageForTheTeam() throws {
+        let url = root.appendingPathComponent("tools/lib/ExportOptions-AppStore.plist")
+        let options = try XCTUnwrap(PropertyListSerialization.propertyList(from: Data(contentsOf: url), format: nil)
+            as? [String: Any])
+        XCTAssertEqual(options["method"] as? String, "app-store-connect")
+        XCTAssertEqual(options["destination"] as? String, "export", "the export never uploads; --upload is its own step")
+        XCTAssertEqual(options["teamID"] as? String, "3B8SMSSAX4")
+        XCTAssertEqual(options["signingStyle"] as? String, "automatic")
+    }
+
+    /// Mutation: drop a product check, or let the script upload without --upload - red.
+    func testTheStoreScriptChecksItsProductAndUploadsOnlyWhenAsked() throws {
+        let script = try String(contentsOf: root.appendingPathComponent("tools/release-store.sh"), encoding: .utf8)
+        for check in ["MACEM_STORE_BUILD=YES", "ARCHS=arm64", "pkgutil --check-signature", "com.apple.security.app-sandbox",
+                      "get-task-allow", "PrivacyInfo.xcprivacy", "ITSAppUsesNonExemptEncryption", "Sparkle.framework",
+                      "ExportOptions-AppStore.plist", "describe --exact-match --tags HEAD"] {
+            XCTAssertTrue(script.contains(check), "release-store.sh no longer checks \(check)")
+        }
+        XCTAssertEqual(script.components(separatedBy: "--upload-app").count - 1, 1)
+        let guardLine = try XCTUnwrap(script.range(of: "if (( UPLOAD == 1 )); then"))
+        let uploadLine = try XCTUnwrap(script.range(of: "--upload-app"))
+        XCTAssertLessThan(guardLine.lowerBound, uploadLine.lowerBound, "the upload sits behind --upload")
+    }
+}
diff --git a/tools/lib/ExportOptions-AppStore.plist b/tools/lib/ExportOptions-AppStore.plist
new file mode 100644
index 0000000..dd91ad1
--- /dev/null
+++ b/tools/lib/ExportOptions-AppStore.plist
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<!-- App Store export (macTEM#103), used by tools/release-store.sh. Exports a signed .pkg to disk; the
+     upload is a separate step Paul runs (tools/release-store.sh --upload). Automatic signing creates the App Store
+     profile for the app under team 3B8SMSSAX4. -->
+<plist version="1.0">
+<dict>
+	<key>method</key>
+	<string>app-store-connect</string>
+	<key>destination</key>
+	<string>export</string>
+	<key>teamID</key>
+	<string>3B8SMSSAX4</string>
+	<key>signingStyle</key>
+	<string>automatic</string>
+	<key>uploadSymbols</key>
+	<true/>
+	<key>manageAppVersionAndBuildNumber</key>
+	<false/>
+</dict>
+</plist>
diff --git a/tools/release-store.sh b/tools/release-store.sh
new file mode 100755
index 0000000..59cecac
--- /dev/null
+++ b/tools/release-store.sh
@@ -0,0 +1,89 @@
+#!/bin/zsh
+# Builds the macTEM App Store package from the same release tag as the DMG (macTEM#103; one tag, two builds, decision of
+# 2026-11-04). tools/release.sh stays the Developer ID DMG; this is the store flavour beside it, kept as its own script.
+#
+#   tools/release-store.sh            archive, export a signed .pkg, check it
+#   tools/release-store.sh --upload   the same, then validate and upload it to App Store Connect
+#
+# Needs Xcode signed in to the team's Apple ID (team 3B8SMSSAX4): -allowProvisioningUpdates lets Xcode create the Apple
+# Distribution and Mac Installer Distribution certificates and the App Store profile on first use. Validation and upload
+# need an App Store Connect API key: ASC_KEY_ID, ASC_ISSUER_ID, the .p8 in ~/.appstoreconnect/private_keys/. Without
+# the key it builds and checks the package and stops. STORE_BUILD_NUMBER overrides CURRENT_PROJECT_VERSION for a second
+# upload of the same version. Output: build/release/<stamp>/store/macTEM.pkg.
+set -euo pipefail
+
+UPLOAD=0
+for arg in "$@"; do
+  case "$arg" in
+    --upload) UPLOAD=1 ;;
+    *) echo "usage: tools/release-store.sh [--upload]" >&2; exit 2 ;;
+  esac
+done
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+. "$ROOT/tools/lib/developer-dir.sh"
+resolve_mactem_developer_dir
+
+TEAM="${DEVELOPMENT_TEAM:-3B8SMSSAX4}"
+OUT="$ROOT/build/release/$(date +%Y%m%d-%H%M%S)"   # a new folder per run, so a rerun never deletes an earlier archive
+ARCHIVE="$OUT/macTEM-store.xcarchive"
+APP="$ARCHIVE/Products/Applications/macTEM.app"
+EXPORT="$OUT/store"
+
+[[ -z "$(git -C "$ROOT" status --porcelain)" ]] || { echo "The working tree is not clean; commit first so the build has a commit." >&2; exit 1; }
+# Built from a release tag, carrying that tag's version (Config/Version.xcconfig, which release-please bumps).
+TAG="$(git -C "$ROOT" describe --exact-match --tags HEAD 2>/dev/null)" || { echo "HEAD is not a release tag; check out the tag to build (git worktree add … vX.Y.Z)." >&2; exit 1; }
+EXPECTED="${TAG#v}"
+SET="$(sed -n 's/^MARKETING_VERSION = \([0-9.]*\).*/\1/p' "$ROOT/Config/Version.xcconfig")"
+[[ "$SET" == "$EXPECTED" ]] || { echo "Config/Version.xcconfig says $SET but the tag is $TAG." >&2; exit 1; }
+mkdir -p "$OUT"
+
+BUILD_ARGS=()
+[[ -n "${STORE_BUILD_NUMBER:-}" ]] && BUILD_ARGS+=("CURRENT_PROJECT_VERSION=$STORE_BUILD_NUMBER")
+
+echo "== App Store archive ($(git -C "$ROOT" rev-parse --short HEAD))"
+# ARCHS=arm64 on the command line, as tools/release.sh: the project's setting does not reach the package targets.
+# MACEM_STORE_BUILD=YES is the one switch the store build flips: the Sparkle updater (#104) compiles only without it.
+xcodebuild archive -project "$ROOT/macTEM.xcodeproj" -scheme macTEM -configuration Release \
+  -destination 'generic/platform=macOS' -archivePath "$ARCHIVE" ARCHS=arm64 \
+  -allowProvisioningUpdates CODE_SIGN_STYLE=Automatic DEVELOPMENT_TEAM="$TEAM" MACEM_STORE_BUILD=YES \
+  "${BUILD_ARGS[@]}" > "$OUT/archive.log" 2>&1 || { tail -30 "$OUT/archive.log"; exit 1; }
+
+echo "== Export"
+xcodebuild -exportArchive -archivePath "$ARCHIVE" -exportPath "$EXPORT" \
+  -exportOptionsPlist "$ROOT/tools/lib/ExportOptions-AppStore.plist" -allowProvisioningUpdates \
+  > "$OUT/export.log" 2>&1 || { tail -30 "$OUT/export.log"; exit 1; }
+PKG="$(print -l "$EXPORT"/*.pkg(N) | head -1)"
+[[ -f "$PKG" ]] || { echo "The export wrote no .pkg to $EXPORT." >&2; exit 1; }
+
+echo "== Check the package"
+pkgutil --check-signature "$PKG" | grep -q "Installer Distribution\|3rd Party Mac Developer Installer" \
+  || { echo "$PKG is not signed with an installer distribution certificate." >&2; exit 1; }
+for binary in "$APP/Contents/MacOS/macTEM" "$APP"/Contents/Frameworks/{FormatoLibHDF5,FormatoLibSZ,FormatoLibAEC}.framework/{FormatoLibHDF5,FormatoLibSZ,FormatoLibAEC}(N); do
+  [[ "$(lipo -archs "$binary")" == "arm64" ]] || { echo "Not arm64 alone: $binary" >&2; exit 1; }
+done
+codesign -d --entitlements :- "$APP" > "$OUT/store-entitlements.plist" 2>/dev/null
+[[ "$(/usr/libexec/PlistBuddy -c 'Print :com.apple.security.app-sandbox' "$OUT/store-entitlements.plist" 2>/dev/null)" == true ]] \
+  || { echo "The store app is not sandboxed." >&2; exit 1; }
+if /usr/libexec/PlistBuddy -c 'Print :com.apple.security.get-task-allow' "$OUT/store-entitlements.plist" >/dev/null 2>&1; then
+  echo "The store app carries get-task-allow." >&2; exit 1
+fi
+[[ -f "$APP/Contents/Resources/PrivacyInfo.xcprivacy" ]] || { echo "The app has no privacy manifest." >&2; exit 1; }
+[[ "$(/usr/libexec/PlistBuddy -c 'Print :ITSAppUsesNonExemptEncryption' "$APP/Contents/Info.plist" 2>/dev/null)" == false ]] \
+  || { echo "Info.plist does not answer the export-compliance question." >&2; exit 1; }
+[[ ! -d "$APP/Contents/Frameworks/Sparkle.framework" ]] || { echo "Sparkle is in the store build." >&2; exit 1; }
+VERSION="$(/usr/libexec/PlistBuddy -c 'Print :CFBundleShortVersionString' "$APP/Contents/Info.plist")"
+[[ "$VERSION" == "$EXPECTED" ]] || { echo "The built app says $VERSION but the tag is $TAG." >&2; exit 1; }
+echo "macTEM $VERSION: $PKG"
+
+if [[ -z "${ASC_KEY_ID:-}" || -z "${ASC_ISSUER_ID:-}" ]]; then
+  echo "No App Store Connect API key (ASC_KEY_ID, ASC_ISSUER_ID): built and checked, not validated or uploaded."
+  exit 0
+fi
+echo "== Validate with App Store Connect"
+xcrun altool --validate-app -f "$PKG" -t macos --apiKey "$ASC_KEY_ID" --apiIssuer "$ASC_ISSUER_ID"
+if (( UPLOAD == 1 )); then
+  echo "== Upload to App Store Connect"
+  xcrun altool --upload-app -f "$PKG" -t macos --apiKey "$ASC_KEY_ID" --apiIssuer "$ASC_ISSUER_ID"
+  echo "Uploaded. The build shows in App Store Connect > TestFlight after processing (minutes to an hour)."
+fi