Support Codex terminal launch

agent/box_agent.py

@@ -319,7 +319,7 @@ def start(
 		`window_id` is the tmux session name. The cloud picks it (default
 		`bux-w1`); we sanitize defensively. First attach to a window
 		creates it via `tmux new-session -A -d` and seeds the launch
-		command (claude / bash). Subsequent attaches just open another
+		command (claude / codex / bash). Subsequent attaches just open another
 		client onto the same tmux session.
 
 		`launch` and `dsp_enabled` are only honored when we're CREATING
@@ -411,6 +411,7 @@ def _ensure_tmux_window(
 		session. Splitting create-vs-attach this way avoids "session
 		not found" races and lets us seed `launch` only on first create.
 		"""
+		import shlex
 		import subprocess
 
 		def _run(args: list[str]) -> int:
@@ -442,6 +443,10 @@ def _run(args: list[str]) -> int:
 			# `; exec bash -l` so when claude quits the user lands in a
 			# bash prompt instead of the tmux session ending.
 			cmd_str = f'{claude_cmd}; exec bash -l'
+		elif launch == 'codex':
+			# Same tmux lifecycle as Claude: Codex owns the first command,
+			# and quitting drops the user to a normal login shell.
+			cmd_str = f'{shlex.quote(CODEX_BIN)}; exec bash -l'
 		else:
 			cmd_str = 'exec bash -l'
 
@@ -884,6 +889,11 @@ async def _handle(self, raw: str | bytes) -> None:
 			if new != self._dsp_enabled:
 				LOG.info('dsp_enabled %s → %s', self._dsp_enabled, new)
 				self._dsp_enabled = new
+		elif cmd == 'update_default_agent':
+			# Cloud owns the persisted default. The launch choice is carried
+			# on each shell_attach, so the box-agent only ACKs this command to
+			# avoid warning noise on older/no-op setting pushes.
+			await self._send({'type': 'ack', 'cmd': cmd, 'ok': True})
 		elif cmd == 'shell_input':
 			import base64 as _b64
 

agent/test_box_agent.py

@@ -0,0 +1,36 @@
+import unittest
+import sys
+import types
+from unittest import mock
+
+sys.modules.setdefault('websockets', types.ModuleType('websockets'))
+
+from agent import box_agent
+
+
+class ShellSessionLaunchTest(unittest.TestCase):
+    def test_codex_launch_seeds_tmux_window_with_codex_cli(self) -> None:
+        calls: list[list[str]] = []
+
+        def fake_run(args: list[str], **_kwargs: object) -> mock.Mock:
+            calls.append(args)
+            # First call is has-session: report missing so creation path runs.
+            return mock.Mock(returncode=1 if len(calls) == 1 else 0)
+
+        with (
+            mock.patch.object(box_agent, 'CODEX_BIN', '/usr/local/bin/codex'),
+            mock.patch('subprocess.run', side_effect=fake_run),
+        ):
+            box_agent.ShellSession._ensure_tmux_window(
+                'bux-w1',
+                launch='codex',
+                dsp_enabled=True,
+            )
+
+        self.assertEqual(calls[0], ['/usr/bin/tmux', 'has-session', '-t', 'bux-w1'])
+        self.assertEqual(calls[1][-3:], ['/bin/bash', '-lc', '/usr/local/bin/codex; exec bash -l'])
+        self.assertEqual(calls[2], ['/usr/bin/tmux', 'set-window-option', '-t', 'bux-w1', 'aggressive-resize', 'on'])
+
+
+if __name__ == '__main__':
+    unittest.main()