Replace exec terminal with a real PTY (node-pty + xterm.js over WebSocket)

The old terminal spawned a fresh `bash -lc` per command, which re-sourced the
login shell every time and felt slow and "custom". Now the daemon spawns a
genuine persistent PTY (node-pty) and relays it over a `/api/pty` WebSocket,
rendered with xterm.js — a real, responsive shell window with full line
editing, colors, and interactive programs.

- daemon: lazy-loaded node-pty + ws PTY relay (self-heals spawn-helper perms),
  marked external in tsup so the native addon resolves at runtime
- app: xterm.js terminal themed from the app's CSS variables, with the
  Codex-style tab bar "+" menu (New terminal / Clear)
- electron: spawn the daemon under standalone Node (not Electron's Node) so
  the node-pty prebuilt binary loads

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: EfeAcar6431

packages/app/electron/main.ts

@@ -44,13 +44,41 @@ async function ping(port: number): Promise<DaemonInfo | null> {
   }
 }
 
-/** Resolve the `coderouter` CLI entry to spawn the daemon. */
-function resolveCli(): { cmd: string; args: string[] } {
-  // Prefer an explicit override, else the locally built CLI, else PATH.
-  if (process.env.CODEROUTER_CLI) return { cmd: process.execPath, args: [process.env.CODEROUTER_CLI] };
-  const localCli = join(app.getAppPath(), '..', 'cli', 'dist', 'cli.js');
-  if (existsSync(localCli)) return { cmd: process.execPath, args: [localCli] };
-  return { cmd: 'coderouter', args: [] };
+/**
+ * Locate a standalone Node binary. The daemon must run under regular Node
+ * (not Electron's bundled Node) so native addons like `node-pty` — which
+ * powers the Studio terminal and ships a prebuilt binary for the standard
+ * Node ABI — load correctly. Returns null if none can be found.
+ */
+function findNode(): string | null {
+  const candidates = [
+    process.env.CODEROUTER_NODE,
+    process.env.npm_node_execpath,
+    '/opt/homebrew/bin/node',
+    '/usr/local/bin/node',
+    '/usr/bin/node',
+  ];
+  for (const c of candidates) {
+    if (c && existsSync(c) && !/electron/i.test(c)) return c;
+  }
+  return null;
+}
+
+/** Resolve the command used to spawn the daemon. */
+function resolveCli(): { cmd: string; args: string[]; electronNode: boolean } {
+  const cliPath = process.env.CODEROUTER_CLI || (() => {
+    const local = join(app.getAppPath(), '..', 'cli', 'dist', 'cli.js');
+    return existsSync(local) ? local : null;
+  })();
+
+  if (cliPath) {
+    const node = findNode();
+    // Prefer standalone Node so node-pty loads; fall back to Electron-as-Node
+    // (the daemon still works, only the terminal backend would be unavailable).
+    if (node) return { cmd: node, args: [cliPath], electronNode: false };
+    return { cmd: process.execPath, args: [cliPath], electronNode: true };
+  }
+  return { cmd: 'coderouter', args: [], electronNode: false };
 }
 
 async function ensureDaemon(): Promise<DaemonInfo> {
@@ -67,14 +95,13 @@ async function ensureDaemon(): Promise<DaemonInfo> {
     if (alive) return alive;
   }
 
-  const { cmd, args } = resolveCli();
-  // When spawning via Electron's own binary (process.execPath), it must be
-  // told to behave as plain Node, otherwise it boots a second app instance.
-  const runAsNode = cmd === process.execPath;
+  const { cmd, args, electronNode } = resolveCli();
+  // When falling back to Electron's own binary, it must be told to behave as
+  // plain Node, otherwise it boots a second app instance.
   const child = spawn(cmd, [...args, 'daemon'], {
     detached: true,
     stdio: 'ignore',
-    env: runAsNode ? { ...process.env, ELECTRON_RUN_AS_NODE: '1' } : process.env,
+    env: electronNode ? { ...process.env, ELECTRON_RUN_AS_NODE: '1' } : process.env,
   });
   child.unref();
 

packages/app/package.json

@@ -17,6 +17,8 @@
   },
   "dependencies": {
     "@coderouter/core": "workspace:*",
+    "@xterm/addon-fit": "^0.11.0",
+    "@xterm/xterm": "^6.0.0",
     "lucide-react": "^1.21.0",
     "react-markdown": "^10.1.0",
     "remark-gfm": "^4.0.1"