Set the terminal window title from session state

README.md

@@ -212,6 +212,7 @@ Tokens are stripped from the in-memory history buffer and masked on every displa
 | `theme` | Terminal colour theme | `glean` (default), `mono`, `neon` |
 | `default_page_size` | Default result count for search and entities | Integer, default `10` |
 | `mock_corpus_path` | JSON file backing mock mode | Path; unset uses the built-in corpus |
+| `window_title` | Terminal window/tab title | `full` (default, includes the instance host), `plain` (mode only), `off` |
 
 Config lives at `~/.gleancode/config.json`. Change any key with `/config set <key> <value>`. Use `/mode live|mock|auto` to force a mode without editing config.
 

glean_code/cli.py

@@ -30,25 +30,42 @@ def main() -> None:
 
     setup_readline()
 
-    while session.running:
-        try:
-            bar = ui.status_bar(
-                mode=config.effective_mode,
-                instance=config.instance,
-                has_token=config.is_live_ready,
-                act_as=config.act_as,
-                chat_id=session.current_chat_id,
-            )
-            if bar:
-                print(bar)
-            line = input(ui.prompt_str(config.effective_mode))
-        except (EOFError, KeyboardInterrupt):
-            print()
-            break
-        try:
-            dispatch(session, line)
-        except Exception as e:  # defensive: never crash the REPL
-            ui.print_err(f"Unhandled error: {e}")
+    # Terminal title tracks mode and instance, so several open windows stay
+    # tellable apart. Only rewritten when the state actually changes.
+    last_title = None
+    try:
+        while session.running:
+            try:
+                title = ui.title_text(
+                    mode=config.effective_mode,
+                    instance=config.instance,
+                    has_token=config.is_live_ready,
+                    style_name=config.window_title,
+                )
+                if title and title != last_title:
+                    ui.set_title(title)
+                    last_title = title
+
+                bar = ui.status_bar(
+                    mode=config.effective_mode,
+                    instance=config.instance,
+                    has_token=config.is_live_ready,
+                    act_as=config.act_as,
+                    chat_id=session.current_chat_id,
+                )
+                if bar:
+                    print(bar)
+                line = input(ui.prompt_str(config.effective_mode))
+            except (EOFError, KeyboardInterrupt):
+                print()
+                break
+            try:
+                dispatch(session, line)
+            except Exception as e:  # defensive: never crash the REPL
+                ui.print_err(f"Unhandled error: {e}")
+    finally:
+        if last_title:
+            ui.clear_title()
 
 
 if __name__ == "__main__":

glean_code/config.py

@@ -46,6 +46,7 @@ class Config:
     theme: str = "glean"                      # glean | mono | neon
     default_page_size: int = 10
     mock_corpus_path: Optional[str] = None    # JSON file backing mock mode; falls back to the built-in corpus
+    window_title: str = "full"                # full | plain (no hostname) | off
     history: list = field(default_factory=list)
 
     # ---- Interactive OAuth (SSO) settings ----

glean_code/ui.py

@@ -80,6 +80,51 @@ def hyperlink(url: str, text: str) -> str:
     return f"\033]8;;{url}\033\\{text}\033]8;;\033\\"
 
 
+def title_text(
+    mode: str,
+    instance: Optional[str] = None,
+    has_token: bool = False,
+    style_name: str = "full",
+) -> str:
+    """Build the terminal window/tab title for the current session state.
+
+    style_name:
+        full   "Glean Code - acme-be.glean.com (live)"
+        plain  "Glean Code (live)"      - omits the tenant hostname
+        off    ""                       - caller should not set a title
+    """
+    if style_name == "off":
+        return ""
+
+    label = mode if mode in ("live", "mock") else "auto"
+    if mode == "auto":
+        label = "live" if has_token else "mock"
+
+    if style_name == "plain" or not instance:
+        return f"Glean Code ({label})"
+
+    host = instance
+    if "://" in host:
+        host = host.split("://", 1)[1].split("/")[0]
+    return f"Glean Code - {host} ({label})"
+
+
+def set_title(text: str) -> None:
+    """Set the terminal window and tab title via OSC 0.
+
+    No-op when stdout is not a TTY, so piped runs stay clean.
+    """
+    if not sys.stdout.isatty():
+        return
+    sys.stdout.write(f"\033]0;{text}\007")
+    sys.stdout.flush()
+
+
+def clear_title() -> None:
+    """Hand the title back to the shell on exit."""
+    set_title("")
+
+
 def term_width(default: int = 80) -> int:
     try:
         return shutil.get_terminal_size().columns

tests/test_ui.py

@@ -1,8 +1,10 @@
 """Tests for glean_code.ui"""
+import io
 import os
 import sys
 import unittest
 from pathlib import Path
+from unittest import mock
 from unittest.mock import patch
 
 sys.path.insert(0, str(Path(__file__).parent.parent))
@@ -295,3 +297,56 @@ def test_short_chat_id_not_truncated(self):
 
 if __name__ == "__main__":
     unittest.main()
+
+
+class TestTitleText(unittest.TestCase):
+    def test_full_includes_host_and_mode(self):
+        self.assertEqual(
+            ui.title_text("live", "acme-be.glean.com", True),
+            "Glean Code - acme-be.glean.com (live)",
+        )
+
+    def test_plain_omits_the_hostname(self):
+        self.assertEqual(
+            ui.title_text("live", "acme-be.glean.com", True, "plain"),
+            "Glean Code (live)",
+        )
+
+    def test_off_returns_empty(self):
+        self.assertEqual(ui.title_text("live", "acme-be.glean.com", True, "off"), "")
+
+    def test_auto_resolves_to_live_or_mock(self):
+        self.assertIn("(live)", ui.title_text("auto", "h", has_token=True))
+        self.assertIn("(mock)", ui.title_text("auto", "h", has_token=False))
+
+    def test_no_instance_falls_back_to_short_form(self):
+        self.assertEqual(ui.title_text("mock", None, False), "Glean Code (mock)")
+
+    def test_scheme_and_path_are_stripped_from_host(self):
+        self.assertEqual(
+            ui.title_text("live", "https://acme-be.glean.com/rest/api/v1", True),
+            "Glean Code - acme-be.glean.com (live)",
+        )
+
+
+class TestSetTitle(unittest.TestCase):
+    def test_writes_osc_sequence_when_tty(self):
+        buf = io.StringIO()
+        buf.isatty = lambda: True
+        with mock.patch.object(ui.sys, "stdout", buf):
+            ui.set_title("Hello")
+        self.assertEqual(buf.getvalue(), "\033]0;Hello\007")
+
+    def test_silent_when_not_a_tty(self):
+        buf = io.StringIO()
+        buf.isatty = lambda: False
+        with mock.patch.object(ui.sys, "stdout", buf):
+            ui.set_title("Hello")
+        self.assertEqual(buf.getvalue(), "")
+
+    def test_clear_title_emits_empty_title(self):
+        buf = io.StringIO()
+        buf.isatty = lambda: True
+        with mock.patch.object(ui.sys, "stdout", buf):
+            ui.clear_title()
+        self.assertEqual(buf.getvalue(), "\033]0;\007")