diff --git a/muxplex/frontend/app.js b/muxplex/frontend/app.js
index 1d390a0..424d07d 100644
--- a/muxplex/frontend/app.js
+++ b/muxplex/frontend/app.js
@@ -1402,8 +1402,10 @@ function showFabSessionInput() {
 
 /**
  * Create a new tmux session via POST /api/sessions.
- * Shows a toast with the created session name, calls pollSessions() to refresh,
- * and if ss.auto_open_created !== false, calls openSession(data.name) after 500ms.
+ * Shows a toast, then polls _currentSessions until the session name appears
+ * (or times out after 30s) before calling openSession — this handles commands
+ * that take time to create the tmux session (e.g. cloning repos, setup scripts).
+ * If auto_open_created is false in server settings, skips the auto-open.
  * @param {string} name - The session name to create.
  * @returns {Promise<void>}
  */
@@ -1411,12 +1413,34 @@ async function createNewSession(name) {
   try {
     const res = await api('POST', '/api/sessions', { name });
     const data = await res.json();
-    showToast('Created: ' + (data.name || name));
-    await pollSessions();
+    const sessionName = data.name || name;
+    showToast('Creating session \'' + sessionName + '\'…');
+
     const ss = _serverSettings || {};
-    if (ss.auto_open_created !== false) {
-      setTimeout(() => openSession(data.name || name), 500);
+    if (ss.auto_open_created === false) {
+      // Auto-open disabled — just do one refresh
+      await pollSessions();
+      return;
     }
+
+    // Poll until the session appears in _currentSessions (max 30s, every 2s)
+    var attempts = 0;
+    var maxAttempts = 15;
+    var pollForSession = setInterval(async function() {
+      attempts++;
+      await pollSessions();
+      var found = _currentSessions && _currentSessions.find(function(s) {
+        return s.name === sessionName;
+      });
+      if (found) {
+        clearInterval(pollForSession);
+        showToast('Session \'' + sessionName + '\' ready');
+        openSession(sessionName);
+      } else if (attempts >= maxAttempts) {
+        clearInterval(pollForSession);
+        showToast('Session \'' + sessionName + '\' is taking longer than expected');
+      }
+    }, 2000);
   } catch (err) {
     showToast(err.message || 'Failed to create session');
   }
diff --git a/muxplex/frontend/tests/test_app.mjs b/muxplex/frontend/tests/test_app.mjs
index 8e4f7a5..5cc069c 100644
--- a/muxplex/frontend/tests/test_app.mjs
+++ b/muxplex/frontend/tests/test_app.mjs
@@ -2382,4 +2382,28 @@ test('app.js source uses 500ms debounce for template input and references new_se
   assert.ok(source.includes('new_session_template'), 'must reference new_session_template setting key');
 });
 
+test('createNewSession polls for session before auto-opening (not immediate setTimeout openSession)', () => {
+  // The old behavior was: setTimeout(() => openSession(...), 500) immediately after POST.
+  // The new behavior must use a polling interval to wait for the session to appear in
+  // _currentSessions before calling openSession — so the immediate pattern must be gone.
+  const source = fs.readFileSync(
+    new URL('../app.js', import.meta.url), 'utf8'
+  );
+  // Extract the createNewSession function body
+  const start = source.indexOf('async function createNewSession(');
+  assert.ok(start !== -1, 'createNewSession function must exist');
+  // Find the end of the function (next function declaration at same indent level)
+  const snippet = source.slice(start, start + 2000);
+  // Must NOT contain the old immediate-open pattern inside createNewSession
+  assert.ok(
+    !snippet.includes("setTimeout(() => openSession"),
+    'createNewSession must not use immediate setTimeout(() => openSession) — should poll instead'
+  );
+  // Must contain a polling mechanism (setInterval)
+  assert.ok(
+    snippet.includes('setInterval'),
+    'createNewSession must use setInterval to poll for session readiness'
+  );
+});
+
 
diff --git a/muxplex/tests/test_frontend_js.py b/muxplex/tests/test_frontend_js.py
index 7207640..8a13cf3 100644
--- a/muxplex/tests/test_frontend_js.py
+++ b/muxplex/tests/test_frontend_js.py
@@ -1721,8 +1721,8 @@ def test_create_new_session_auto_opens_session() -> None:
     )
 
 
-def test_create_new_session_auto_open_delay() -> None:
-    """createNewSession must use a 500ms delay before calling openSession."""
+def test_create_new_session_polls_before_open() -> None:
+    """createNewSession must poll for the session to appear before calling openSession (not immediate setTimeout)."""
     match = re.search(
         r"async function createNewSession\s*\(\w+\)\s*\{(.*?)(?=\nasync function |\nfunction |\n// )",
         _JS,
@@ -1730,7 +1730,14 @@ def test_create_new_session_auto_open_delay() -> None:
     )
     assert match, "createNewSession function not found"
     body = match.group(1)
-    assert "500" in body, "createNewSession must use 500ms delay before openSession"
+    # Old immediate pattern must be gone
+    assert "setTimeout(() => openSession" not in body, (
+        "createNewSession must not use immediate setTimeout(() => openSession) — should poll instead"
+    )
+    # New polling pattern must be present
+    assert "setInterval" in body, (
+        "createNewSession must use setInterval to poll for session readiness"
+    )
 
 
 def test_bind_static_event_listeners_binds_new_session_btn() -> None: