diff --git a/README.md b/README.md
index 27398e1a..8990724e 100644
--- a/README.md
+++ b/README.md
@@ -110,10 +110,18 @@ The desktop supervisor lives under `frontend/` and is started separately:
 
 ```bash
 cd frontend
+nvm use 20 || nvm install 20
 npm install
 npm run dev   # electron-forge start
 ```
 
+The Electron frontend is currently developed and packaged on **Node 20.x**.
+Newer Node 24/26 runtimes currently hit upstream Electron / Electron Forge
+install bugs that can leave `node_modules/electron` half-installed and make
+`npm run dev` fail with `Electron failed to install correctly`. The frontend
+package fails fast on unsupported Node versions so contributors see the fix
+before a partial install corrupts `node_modules`.
+
 Heads-up: `npm run dev` does **not** start the daemon for you. Start it first
 (`ao start`, see above) — the renderer attaches to the running daemon over
 loopback (`127.0.0.1:3001` by default, the `AO_PORT` from the table below).
diff --git a/frontend/.nvmrc b/frontend/.nvmrc
new file mode 100644
index 00000000..209e3ef4
--- /dev/null
+++ b/frontend/.nvmrc
@@ -0,0 +1 @@
+20
diff --git a/frontend/package.json b/frontend/package.json
index 12429528..a4689650 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -6,6 +6,9 @@
 	"description": "Electron + TypeScript frontend for the agent-orchestrator rewrite",
 	"author": "Agent Orchestrator",
 	"license": "MIT",
+	"engines": {
+		"node": "20.x"
+	},
 	"homepage": "https://github.com/aoagents/agent-orchestrator",
 	"main": ".vite/build/main.js",
 	"repository": {
@@ -13,6 +16,7 @@
 		"url": "https://github.com/aoagents/agent-orchestrator"
 	},
 	"scripts": {
+		"preinstall": "node ./scripts/check-node-version.mjs",
 		"build:daemon": "node ./scripts/build-daemon.mjs",
 		"dev": "electron-forge start",
 		"dev:web": "VITE_NO_ELECTRON=1 vite --config vite.renderer.config.ts",
diff --git a/frontend/scripts/check-node-version.mjs b/frontend/scripts/check-node-version.mjs
new file mode 100644
index 00000000..8e4612de
--- /dev/null
+++ b/frontend/scripts/check-node-version.mjs
@@ -0,0 +1,23 @@
+const supportedMajor = 20;
+const currentMajor = Number.parseInt(process.versions.node.split(".")[0], 10);
+
+if (currentMajor !== supportedMajor) {
+	console.error(
+		[
+			`Unsupported Node.js runtime: ${process.versions.node}.`,
+			`The Electron frontend is currently supported on Node ${supportedMajor}.x only.`,
+			"",
+			"Why this is enforced:",
+			"- CI and desktop packaging run on Node 20.",
+			"- Newer Node 24/26 releases currently hit upstream Electron/Forge install bugs",
+			"  that can leave node_modules/electron partially extracted and make",
+			"  `npm run dev` fail with `Electron failed to install correctly`.",
+			"",
+			"Switch to Node 20 and reinstall dependencies:",
+			"  nvm use 20 || nvm install 20",
+			"  rm -rf node_modules",
+			"  npm ci",
+		].join("\n"),
+	);
+	process.exit(1);
+}