Plugins can schedule notifications and cancel them

What

Plugins add features to Claude Code and can ask it to show you notifications.

• ui.notify now accepts key, delayMs, at and untilBack, so a plugin can schedule a notice, send it when you are away, or replace an earlier one with the same key. Before, it sent only text and a title.
• ui.cancelNotify(key) cancels a notification by its key.
• In headless sessions (running without the interactive screen), notices go to the connected host as ui_notify and ui_notify_cancel messages under the plugin's name, with delay_ms, at, until_back and key. Text is capped at 1000 characters and the title at 120. Before, notify always reported there was nowhere to show it.
• These messages are left out of the stream-json output.
• Plugins also gain a way to read the permission mode (permissionMode).

Why

Plugin authors can time notices and clear stale ones. If you read stream-json output, these notification messages do not appear there.