Karui Tech Specs

How it works

A Focus silences the apps you choose and allows only Karui.
For each notification from those apps, iOS 27’s Shortcuts app runs the Karui Shortcut, which passes the notification’s app, title, text, and sender to Karui.
Karui classifies the notification as Important, Neutral, or Spam.
Karui posts Important notifications again, and your Focus lets them through. Tapping one opens the app it came from, or the conversation itself in Messages and WhatsApp when Karui has the sender’s number. With Karui for Mac on your Mac, it opens the exact email or message in Spark, Slack, or Messages. Neutral and Spam notifications stay quiet. Every notification is kept in History, and Neutral ones can also appear in a daily summary.

Apple Push Notification serviceDelivers notifications from other apps’ servers

A notification from an app your Focus silences

Your device

Karui ShortcutRuns on “When I receive a notification” and passes the app, title, text, and sender to Karui

Karui

Uses hard-coded rules for important contacts, one-time codes, urgent terms, and mentions of your name, handles, or nicknames
If no hard-coded rule is triggered, Karui asks Apple’s on-device model, with your names, terms, and calendar as private context
If Apple’s on-device model isn’t available, rules decide and Karui rechecks later

Apple’s on-device Foundation Model

Private Cloud Sorting · offered at setup

Apple’s Private Cloud ComputeKarui asks it directly, or through your Shortcut’s Use Model while Apple Intelligence is busy

Important only

Karui’s alertPosted again; your Focus lets it through.

Every result

HistorySaved on your device with its reason.

Optional · with Karui for Mac

Your iCloud accountHistory to the Mac; links and read marks back

Karui for Mac

Hard-coded deterministic rules on your device decide first. Messages from your important contacts, messages that mention one of your names, one-time codes, and messages matching your urgent terms are always Important.
Everything else goes to Apple’s on-device Foundation Models, with your names, terms, important apps, and upcoming calendar events as private context. The model returns a category, a confidence, a short reason, and an interest score from 1 to 5 that ranks the daily summary.
When the on-device model isn’t available, for example when iOS limits it while Karui runs in the background, fallback rules decide instead, and Karui rechecks those notifications later. See Technical Note KN001.
Private Cloud Sorting, offered at setup, asks Apple’s Private Cloud Compute when the on-device model couldn’t sort a notification, or after every on-device answer with When to Ask set to Before Alerting. Karui asks directly when it can, and through your Shortcut’s Use Model action while Apple Intelligence on your iPhone is busy. See Technical Note KN002.
Karui Cloud Sorting, by invite only, sends every notification the on-device model would sort through Karui’s server to OpenAI’s GPT-6 Luna Decisions, and its answer sets the category. When it answers, Private Cloud Compute isn’t asked. See Technical Note KN006.

On-device classification usually takes about 4 seconds on iPhone 17 Pro. Private Cloud Sorting usually adds 2 to 3 seconds, whether Karui asks or your Shortcut does.
iOS gives apps in the background a small share of the on-device model. After a burst of notifications, Karui may sort some with fallback rules instead of the model for a while, then rechecks them when you open Karui, or right away with Private Cloud Sorting on. Why this happens.
Karui can misclassify a notification. Check Notification Center and Karui’s History when something may have been missed.

Karui has no account and sends no analytics, and unless you join the invite-only Karui Cloud Sorting, it has no server. Your VIPs, settings, and History stay on your device unless you use Karui for Mac.
Private Cloud Sorting sends a notification’s text and app name, your names, and your sorting terms to Apple’s Private Cloud Compute. Anything the rules decide, contact details, and calendar events are never sent. See the privacy policy.
Karui Cloud Sorting is invite-only and stays off unless you accept an invite. With it on, the same data Private Cloud Sorting sends goes through Karui’s server, hosted on Vercel, to OpenAI’s decision model, which returns only a category and its probabilities. Nothing is stored on the server.
With Karui for Mac, your iPhone and Mac exchange data through your own iCloud account, with no server in between: links and read marks from the Mac and, if you turn on Show History on your Mac, your History and sorting settings from the iPhone. Notification text and settings are end-to-end encrypted. Without the Mac app, Karui only checks iCloud for a Mac each time it opens. See Technical Note KN004.

iOS or iPadOS 27 or later. Spam filtering and deadline reminders also need Apple Intelligence on: iPhone 15 Pro, iPhone 15 Pro Max, iPhone Air, any iPhone 16 model, or later; iPad mini (A17 Pro), or an iPad Air or iPad Pro with M1 or later. Viewing unsent messages works without it. iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air run Apple’s more capable on-device model.
The Shortcuts app with the standard Karui Shortcut, and a Focus that allows Karui.