Notification hook fires ~8 seconds after permission prompt appears

Summary

The Notification hook event fires approximately 8 seconds after the permission prompt is displayed in the terminal. This makes it impractical for desktop notification workflows where users expect near-instant alerts.

Environment

• Claude Code version: 2.1.89
• OS: NixOS (Linux 6.18.20, Wayland/niri)
• Terminal: Ghostty

Steps to reproduce

1. Configure a Notification hook in ~/.claude/settings.json:

``json
{
"hooks": {
"Notification": [
{
"matcher": "permission_prompt",
"hooks": [
{
"type": "command",
"command": "bash ~/notification-hook.sh"
}
]
}
]
}
}
``

1. Have the hook script log timestamps
2. Trigger any tool use that requires permission
3. Observe the permission prompt in the terminal
4. Wait for the hook to fire

Observed behavior

The hook script itself executes in ~100ms, but there is a consistent ~8 second delay between the permission prompt appearing in the terminal and Claude Code firing the Notification event.

Profiling evidence

T+0ms: hook started
T+12ms: stdin read
T+33ms: jq parsed (type=permission_prompt)
T+94ms: window resolved
T+97ms: launching notification
T+101ms: hook done

The bottleneck is entirely internal to Claude Code — the hook runs fast once invoked.

Expected behavior

The Notification hook should fire within ~500ms of the permission prompt being displayed. The primary use case for this hook is desktop notifications (e.g. via dunst/libnotify) to alert the user that Claude needs input. An 8-second delay defeats the purpose.

Additional context

The Stop hook has a similar delay (~4-8 seconds after Claude finishes its turn). Both delays appear to be caused by the same internal processing pipeline.