diff --git a/agent/cmd/behavision-setup/main.go b/agent/cmd/behavision-setup/main.go
index 003ce44..5cd4996 100644
--- a/agent/cmd/behavision-setup/main.go
+++ b/agent/cmd/behavision-setup/main.go
@@ -266,10 +266,19 @@ func findPython() (string, string, error) {
 		}
 	}
 
-	msg := "no Python 3.10 or newer was found on this PC.\n\n" +
-		"    Install it from https://www.python.org/downloads/windows/\n" +
-		"    and tick \"Add python.exe to PATH\" on the first screen,\n" +
-		"    then run this again."
+	// The advice has to match the machine. Telling a Mac user to tick "Add
+	// python.exe to PATH" on a Windows installer page reads as software that
+	// does not know where it is running, which is exactly the moment somebody
+	// stops trusting the rest of what it says.
+	msg := "no Python 3.10 or newer was found on this computer.\n\n"
+	if runtime.GOOS == "windows" {
+		msg += "    Install it from https://www.python.org/downloads/windows/\n" +
+			"    and tick \"Add python.exe to PATH\" on the first screen,\n" +
+			"    then run this again."
+	} else {
+		msg += "    Install it with `brew install python@3.12`, or from\n" +
+			"    https://www.python.org/downloads/macos/, then run this again."
+	}
 	if len(tried) > 0 {
 		msg += "\n\n    Found, but too old: " + strings.Join(tried, ", ")
 	}
diff --git a/release.sh b/release.sh
index 0e3e865..5fb1d1e 100755
--- a/release.sh
+++ b/release.sh
@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
 # Build the Windows shop-PC package and publish it as a Gitea release.
 #
-#   ./release.sh v0.4.2                 build dist/Behavision-v0.4.2-windows-x64.zip and publish
+#   ./release.sh v0.4.2                 build the Windows zip and publish
 #   PUBLISH=0 ./release.sh v0.4.2       build only
+#   MAC=1 ./release.sh v0.4.2           also build and attach the macOS zip
 #   DEMO_PACK=demo-cameras.enc ./release.sh v0.4.4-demo
 #                                       a demo build: the sealed bundle from
 #                                       behavision-demo-pack ships in engine-src,
@@ -22,6 +23,8 @@ TAG=${1:?usage: release.sh vX.Y.Z}
 REPO_API=https://gitapp.workolik.com/api/v1/repos/Loyaly/Behavision
 STAGE=dist/Behavision
 ZIP="dist/Behavision-$TAG-windows-x64.zip"
+MACZIP="dist/Behavision-$TAG-macos-arm64.zip"
+MACSTAGE=dist/Behavision-mac
 
 step() { printf '\n\033[1m%s\033[0m\n' "$*"; }
 case "$(git describe --tags --always --dirty)" in *-dirty) echo "refusing to release uncommitted changes" >&2; exit 1;; esac
@@ -62,9 +65,39 @@ step "4. Package"
 rm -f "$ZIP" && (cd dist && zip -qr "$(basename "$ZIP")" Behavision) && ls -la "$ZIP" | awk '{print "   " $5 " bytes  " $9}'
 unzip -l "$ZIP" | grep -E "Behavision\.exe|agent\.exe|setup\.exe|\.whl|INSTALL" | awk '{print "   " $4}'
 
+# --- macOS, same SOURCE-install shape as Windows -------------------------
+#
+# Worth stating because it is the reason this is cheap: the Windows package
+# already ships a pure-Python WHEEL and builds a venv on the target machine,
+# because PyInstaller cannot cross-compile. macOS needs nothing different -
+# the same wheel, the same setup tool, a natively built .app instead of an
+# .exe. No frozen engine, no 200 MB, no second packaging story.
+#
+# Two things it is NOT, and the release notes should say so:
+#   * not notarised. macOS blocks an unsigned download outright rather than
+#     warning like SmartScreen, so the first launch needs right-click > Open.
+#     Notarising needs an Apple Developer account.
+#   * arm64 only. Every Mac worth demoing on since 2020, and building a
+#     universal binary doubles the size for machines nobody here has.
+if [ "${MAC:-0}" = "1" ]; then
+  step "5. macOS package"
+  command -v wails >/dev/null || { echo "wails CLI not found; go install github.com/wailsapp/wails/v2/cmd/wails@latest" >&2; exit 1; }
+  rm -rf "$MACSTAGE" && mkdir -p "$MACSTAGE/engine-src"
+  (cd desktop && wails build -platform darwin/arm64 -tags "desktop,production" -skipbindings >/dev/null)
+  cp -R desktop/build/bin/Behavision.app "$MACSTAGE/"
+  (cd agent && CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -trimpath \
+    -ldflags "-s -w -X main.version=$TAG" -o "../$MACSTAGE/behavision-agent" . \
+    && CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -trimpath \
+    -ldflags "-s -w -X main.version=$TAG" -o "../$MACSTAGE/behavision-setup" ./cmd/behavision-setup)
+  # The identical engine payload the Windows package carries.
+  cp -R "$STAGE/engine-src/." "$MACSTAGE/engine-src/"
+  rm -f "$MACZIP" && (cd dist && zip -qry "$(basename "$MACZIP")" Behavision-mac)
+  ls -la "$MACZIP" | awk '{print "   " $5 " bytes  " $9}'
+fi
+
 [ "${PUBLISH:-1}" = "1" ] || { echo "built, not published"; exit 0; }
 
-step "5. Tag and publish"
+step "6. Tag and publish"
 git rev-parse -q --verify "refs/tags/$TAG" >/dev/null || git tag -a "$TAG" -m "$TAG"
 git push -q origin "$TAG"
 # The notes come from a file so they are reviewed, not typed into a shell.
@@ -77,4 +110,5 @@ BODY=$(python3 -c 'import json,sys;print(json.dumps({"tag_name":sys.argv[1],"nam
 REL=$(curl -sS -u "$USER:$PASS" -H 'content-type: application/json' -d "$BODY" "$REPO_API/releases")
 ID=$(printf '%s' "$REL" | python3 -c 'import json,sys;print(json.load(sys.stdin)["id"])')
 curl -sS -u "$USER:$PASS" -F "attachment=@$ZIP" "$REPO_API/releases/$ID/assets?name=$(basename "$ZIP")" >/dev/null
+[ "${MAC:-0}" = "1" ] && curl -sS -u "$USER:$PASS" -F "attachment=@$MACZIP" "$REPO_API/releases/$ID/assets?name=$(basename "$MACZIP")" >/dev/null
 echo "   published: https://gitapp.workolik.com/Loyaly/Behavision/releases/tag/$TAG"