ctrl-c protection, add buffer to avoid accidentally exiting thread (#300)

- add time buffer on ctrl+c on prompt input box to avoid accidental
exit, tells user can press twice to exit

Author: vtrivedy

libs/deepagents-cli/deepagents_cli/config.py

@@ -61,6 +61,8 @@ class SessionState:
 
     def __init__(self, auto_approve: bool = False):
         self.auto_approve = auto_approve
+        self.exit_hint_until: float | None = None
+        self.exit_hint_handle = None
 
     def toggle_auto_approve(self) -> bool:
         """Toggle auto-approve and return new state."""

libs/deepagents-cli/deepagents_cli/input.py

@@ -1,7 +1,9 @@
 """Input handling, completers, and prompt session for the CLI."""
 
+import asyncio
 import os
 import re
+import time
 from collections.abc import Callable
 from pathlib import Path
 
@@ -23,6 +25,8 @@
 AT_MENTION_RE = re.compile(r"@(?P<path>(?:[^\s@]|(?<=\\)\s)*)$")
 SLASH_COMMAND_RE = re.compile(r"^/(?P<command>[a-z]*)$")
 
+EXIT_CONFIRM_WINDOW = 3.0
+
 
 class FilePathCompleter(Completer):
     """Activate filesystem completion only when cursor is after '@'."""
@@ -154,6 +158,16 @@ def toolbar() -> list[tuple[str, str]]:
 
         parts.append((base_class, base_msg))
 
+        # Show exit confirmation hint if active
+        hint_until = session_state.exit_hint_until
+        if hint_until is not None:
+            now = time.monotonic()
+            if now < hint_until:
+                parts.append(("", " | "))
+                parts.append(("class:toolbar-exit", " Ctrl+C again to exit "))
+            else:
+                session_state.exit_hint_until = None
+
         return parts
 
     return toolbar
@@ -168,6 +182,44 @@ def create_prompt_session(assistant_id: str, session_state: SessionState) -> Pro
     # Create key bindings
     kb = KeyBindings()
 
+    @kb.add("c-c")
+    def _(event):
+        """Require double Ctrl+C within a short window to exit."""
+        app = event.app
+        now = time.monotonic()
+
+        if session_state.exit_hint_until is not None and now < session_state.exit_hint_until:
+            handle = session_state.exit_hint_handle
+            if handle:
+                handle.cancel()
+                session_state.exit_hint_handle = None
+            session_state.exit_hint_until = None
+            app.invalidate()
+            app.exit(exception=KeyboardInterrupt())
+            return
+
+        session_state.exit_hint_until = now + EXIT_CONFIRM_WINDOW
+
+        handle = session_state.exit_hint_handle
+        if handle:
+            handle.cancel()
+
+        loop = asyncio.get_running_loop()
+        app_ref = app
+
+        def clear_hint():
+            if (
+                session_state.exit_hint_until is not None
+                and time.monotonic() >= session_state.exit_hint_until
+            ):
+                session_state.exit_hint_until = None
+                session_state.exit_hint_handle = None
+                app_ref.invalidate()
+
+        session_state.exit_hint_handle = loop.call_later(EXIT_CONFIRM_WINDOW, clear_hint)
+
+        app.invalidate()
+
     # Bind Ctrl+T to toggle auto-approve
     @kb.add("c-t")
     def _(event):
@@ -240,6 +292,7 @@ def _(event):
             "bottom-toolbar": "noreverse",  # Disable default reverse video
             "toolbar-green": "bg:#10b981 #000000",  # Green for auto-accept ON
             "toolbar-orange": "bg:#f59e0b #000000",  # Orange for manual accept
+            "toolbar-exit": "bg:#2563eb #ffffff",  # Blue for exit hint
         }
     )
 

libs/deepagents-cli/deepagents_cli/main.py

@@ -136,11 +136,14 @@ async def simple_cli(agent, assistant_id: str | None, session_state, baseline_to
     while True:
         try:
             user_input = await session.prompt_async()
+            if session_state.exit_hint_handle:
+                session_state.exit_hint_handle.cancel()
+                session_state.exit_hint_handle = None
+            session_state.exit_hint_until = None
             user_input = user_input.strip()
         except EOFError:
             break
         except KeyboardInterrupt:
-            # Ctrl+C at prompt - exit the program
             console.print("\nGoodbye!", style=COLORS["primary"])
             break