diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3e72b1c..20e18ff 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -50,9 +50,38 @@ jobs:
         with:
           python-version: "3.12"
           cache: pip
+      # Import the Developer ID Application cert into a temporary keychain so
+      # build_macos.sh can codesign. No-op (unsigned build) when the secret is
+      # absent, so forks / unconfigured repos still produce a working .dmg.
+      - name: Import Developer ID certificate
+        env:
+          CERT_B64: ${{ secrets.MACOS_CERTIFICATE_P12_BASE64 }}
+          CERT_PASSWORD: ${{ secrets.MACOS_CERTIFICATE_PASSWORD }}
+        run: |
+          if [ -z "${CERT_B64}" ]; then
+            echo "MACOS_CERTIFICATE_P12_BASE64 not set — building unsigned."
+            exit 0
+          fi
+          KEYCHAIN="$RUNNER_TEMP/signing.keychain-db"
+          KEYCHAIN_PW="$(uuidgen)"
+          printf '%s' "${CERT_B64}" | base64 --decode > "$RUNNER_TEMP/cert.p12"
+          security create-keychain -p "$KEYCHAIN_PW" "$KEYCHAIN"
+          security set-keychain-settings -lut 21600 "$KEYCHAIN"
+          security unlock-keychain -p "$KEYCHAIN_PW" "$KEYCHAIN"
+          security import "$RUNNER_TEMP/cert.p12" -k "$KEYCHAIN" -P "${CERT_PASSWORD}" \
+            -T /usr/bin/codesign -T /usr/bin/security
+          security set-key-partition-list -S apple-tool:,apple:,codesign: \
+            -s -k "$KEYCHAIN_PW" "$KEYCHAIN" >/dev/null
+          security list-keychains -d user -s "$KEYCHAIN" \
+            $(security list-keychains -d user | sed 's/["[:space:]]//g')
+          rm -f "$RUNNER_TEMP/cert.p12"
       - name: Build .app + .dmg
         env:
           MAKE_DMG: "1"
+          MACOS_SIGN_IDENTITY: ${{ secrets.MACOS_SIGN_IDENTITY }}
+          MACOS_NOTARY_APPLE_ID: ${{ secrets.MACOS_NOTARY_APPLE_ID }}
+          MACOS_NOTARY_TEAM_ID: ${{ secrets.MACOS_NOTARY_TEAM_ID }}
+          MACOS_NOTARY_PASSWORD: ${{ secrets.MACOS_NOTARY_PASSWORD }}
         run: bash packaging/build_macos.sh
       - uses: actions/upload-artifact@v4
         with:
diff --git a/docs/building.md b/docs/building.md
index c958f5f..de52fd1 100644
--- a/docs/building.md
+++ b/docs/building.md
@@ -16,9 +16,44 @@ bash packaging/build_macos.sh                 # dist/AutoPTZ.app
 MAKE_DMG=1 bash packaging/build_macos.sh      # + dist/AutoPTZ-<ver>-macos-arm64.dmg
 ```
 
-Produces an unsigned, correctly-named bundle (`CFBundleName=AutoPTZ`). Signing +
-notarization need your Apple Developer ID — the exact `codesign` / `notarytool` /
-`stapler` commands are printed at the end of the script.
+Produces a correctly-named bundle (`CFBundleName=AutoPTZ`). By default it is
+**unsigned** and the script prints the manual `codesign` / `notarytool` / `stapler`
+commands at the end.
+
+### Signing + notarization (opt-in)
+
+Set `MACOS_SIGN_IDENTITY` to your Developer ID and the script signs the `.app` (and,
+with `MAKE_DMG=1`, the `.dmg`). Add notary credentials and it also notarizes +
+staples:
+
+```bash
+export MACOS_SIGN_IDENTITY="Developer ID Application: Your Name (TEAMID)"
+# notarize too (either a stored profile, or Apple-ID creds):
+export MACOS_NOTARY_KEYCHAIN_PROFILE="AUTOPTZ_NOTARY"     # from `notarytool store-credentials`
+#   …or…
+export MACOS_NOTARY_APPLE_ID="you@example.com"
+export MACOS_NOTARY_TEAM_ID="TEAMID"
+export MACOS_NOTARY_PASSWORD="app-specific-password"
+MAKE_DMG=1 bash packaging/build_macos.sh                 # signed + notarized + stapled .dmg
+```
+
+`security find-identity -v -p codesigning` lists your identity + Team ID. Entitlements
+come from `packaging/entitlements.plist` (hardened runtime, required for notarization).
+
+### Signed releases in CI
+
+The [release workflow](../.github/workflows/release.yml) signs + notarizes the published
+`.dmg` automatically once these repository secrets are set (Settings → Secrets and
+variables → Actions); without them it still builds an unsigned `.dmg`:
+
+| Secret | What it is |
+| --- | --- |
+| `MACOS_CERTIFICATE_P12_BASE64` | Your "Developer ID Application" cert exported as `.p12`, base64-encoded (`base64 -i cert.p12 \| pbcopy`). |
+| `MACOS_CERTIFICATE_PASSWORD` | The password you set when exporting the `.p12`. |
+| `MACOS_SIGN_IDENTITY` | `Developer ID Application: Your Name (TEAMID)`. |
+| `MACOS_NOTARY_APPLE_ID` | Apple ID email for notarization. |
+| `MACOS_NOTARY_TEAM_ID` | Your 10-character Team ID. |
+| `MACOS_NOTARY_PASSWORD` | An app-specific password for that Apple ID. |
 
 ## Windows → `.exe` + installer
 
diff --git a/docs/installation.md b/docs/installation.md
index 096964b..7556775 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -6,9 +6,9 @@ Download the latest build for your OS from the
 [Releases page](https://github.com/AutoPTZ/autoptz/releases):
 
 - **macOS** — `AutoPTZ-<version>-macos-arm64.dmg`. Open it and drag **AutoPTZ**
-  to Applications. The builds are currently **unsigned**, so the first launch
-  needs: right-click the app → **Open** → **Open** (or System Settings → Privacy
-  & Security → *Open Anyway*).
+  to Applications. Signed + notarized releases open normally. If you build it
+  yourself unsigned, the first launch needs: right-click the app → **Open** →
+  **Open** (or System Settings → Privacy & Security → *Open Anyway*).
 - **Windows** — `AutoPTZ-<version>-windows-x64-setup.exe`. Run it; it installs
   Start-menu/desktop shortcuts and an uninstaller. SmartScreen may warn on the
   unsigned installer — **More info → Run anyway**.
diff --git a/packaging/build_macos.sh b/packaging/build_macos.sh
index 33eabf9..a0dc406 100755
--- a/packaging/build_macos.sh
+++ b/packaging/build_macos.sh
@@ -26,6 +26,38 @@ echo "==> AutoPTZ macOS build"
 echo "    repo:  ${ROOT}"
 echo "    venv:  ${VENV}"
 
+# ── signing config (opt-in) ──────────────────────────────────────────────────
+# Sign + notarize only when MACOS_SIGN_IDENTITY is set (CI sets it from repo
+# secrets; locally, export it to sign with your Developer ID, e.g.
+#   export MACOS_SIGN_IDENTITY="Developer ID Application: Your Name (TEAMID)"
+# Unset → unsigned build, and the manual sign/notarize commands are printed at
+# the end instead.
+SIGN_IDENTITY="${MACOS_SIGN_IDENTITY:-}"
+
+# Notarize + staple a signed artifact (.app or .dmg) with whichever credentials
+# are available; a no-op (with a note) when none are set.
+notarize_and_staple() {
+    local target="$1"
+    if [[ -n "${MACOS_NOTARY_KEYCHAIN_PROFILE:-}" ]]; then
+        echo "==> Notarizing ${target} via keychain profile ${MACOS_NOTARY_KEYCHAIN_PROFILE}"
+        xcrun notarytool submit "${target}" \
+            --keychain-profile "${MACOS_NOTARY_KEYCHAIN_PROFILE}" --wait
+    elif [[ -n "${MACOS_NOTARY_APPLE_ID:-}" && -n "${MACOS_NOTARY_TEAM_ID:-}" \
+            && -n "${MACOS_NOTARY_PASSWORD:-}" ]]; then
+        echo "==> Notarizing ${target} via Apple ID ${MACOS_NOTARY_APPLE_ID}"
+        xcrun notarytool submit "${target}" \
+            --apple-id "${MACOS_NOTARY_APPLE_ID}" \
+            --team-id "${MACOS_NOTARY_TEAM_ID}" \
+            --password "${MACOS_NOTARY_PASSWORD}" --wait
+    else
+        echo "==> Signed but NOT notarized (no notary credentials): ${target}"
+        echo "    Set MACOS_NOTARY_APPLE_ID/TEAM_ID/PASSWORD or MACOS_NOTARY_KEYCHAIN_PROFILE."
+        return 0
+    fi
+    echo "==> Stapling ${target}"
+    xcrun stapler staple "${target}"
+}
+
 # ── 1. venv ─────────────────────────────────────────────────────────────────
 if [[ ! -x "${PY}" ]]; then
     echo "==> Creating venv at ${VENV}"
@@ -69,6 +101,18 @@ echo "==> Verifying CFBundleName (the app-name fix):"
 /usr/libexec/PlistBuddy -c 'Print :CFBundleName' "${APP}/Contents/Info.plist"
 plutil -lint "${APP}/Contents/Info.plist"
 
+# ── 5b. sign the .app (opt-in) ───────────────────────────────────────────────
+# Deep-sign with the hardened runtime + entitlements so the bundle is notarizable.
+# Must happen BEFORE the .dmg is built so the dmg ships the signed app.
+if [[ -n "${SIGN_IDENTITY}" ]]; then
+    echo "==> Codesigning ${APP} with: ${SIGN_IDENTITY}"
+    codesign --deep --force --options runtime --timestamp \
+        --entitlements packaging/entitlements.plist \
+        --sign "${SIGN_IDENTITY}" "${APP}"
+    codesign --verify --deep --strict --verbose=2 "${APP}"
+    echo "==> ${APP} signed"
+fi
+
 # ── 6. (optional) DMG ─────────────────────────────────────────────────────────
 # MAKE_DMG=1 produces a compressed, versioned dmg with an /Applications symlink
 # (drag-to-install).  Dependency-free (uses macOS hdiutil).  The release workflow
@@ -85,6 +129,19 @@ if [[ "${MAKE_DMG:-0}" == "1" ]]; then
         -ov -format UDZO "${DMG}"
     rm -rf "${STAGE}"
     echo "==> Built ${DMG}"
+
+    # Sign + notarize + staple the distributed .dmg (opt-in).
+    if [[ -n "${SIGN_IDENTITY}" ]]; then
+        echo "==> Codesigning ${DMG}"
+        codesign --force --timestamp --sign "${SIGN_IDENTITY}" "${DMG}"
+        notarize_and_staple "${DMG}"
+    fi
+fi
+
+if [[ -n "${SIGN_IDENTITY}" ]]; then
+    echo
+    echo "==> Signed build complete (notarized if notary credentials were provided)."
+    exit 0
 fi
 
 cat <<'EOF'
diff --git a/packaging/entitlements.plist b/packaging/entitlements.plist
index 1100237..dd5c88a 100644
--- a/packaging/entitlements.plist
+++ b/packaging/entitlements.plist
@@ -4,7 +4,7 @@
   packaging/entitlements.plist : macOS hardened-runtime entitlements.
 
   Applied at signing time via codesign (see packaging/build_macos.sh and
-  docs/v2-rework/11-packaging-and-distribution.md for the exact commands).
+  docs/building.md for the exact commands and the CI signing secrets).
 
   Hardened runtime is REQUIRED for Apple notarization. The JIT and
   unsigned-executable-memory entitlements below are what Python plus PySide6 / Qt