LucidPal
On-device AI calendar assistant for iOS — fully private, no cloud, powered by Qwen3.5.
What is LucidPal?
LucidPal is an on-device AI assistant that understands and manages your iOS calendar through natural language. Every word is processed locally on your iPhone — no data ever leaves the device.
| Feature | Description |
|---|---|
| 100% On-Device | All inference runs via llama.cpp on the Neural Engine. No API keys, no subscriptions, no internet required. |
| Calendar Integration | Create, update, delete and query events using plain English. Conflict detection included. |
| Siri Shortcuts | Ten built-in Siri intents let you manage your calendar, notes, contacts, and habits without ever opening the app. |
| Multi-Session | Full conversation history with named sessions, persisted locally across launches. |
| Notes | Capture quick thoughts in chat; notes are enriched and stored locally. See the Notes guide. |
| Habit Tracker | Track daily habits and log streaks through natural language. See the Habits guide. |
| Document Summarization | Summarize PDFs and text files entirely on-device. See the Document Summarization guide. |
| Web Search | Query DuckDuckGo, Brave, or a self-hosted SearXNG instance — results synthesized locally. See the Web Search guide. |
| Vision / Photo Analysis | Describe images and photos using an optional on-device vision model (Qwen3.5 Vision 4B). See the Vision & Photos guide. |
| Contacts | Look up phone numbers and email addresses from your contacts in chat. See the Contacts guide. |
| Reminders | Set one-off reminders through natural language — synced to the iOS Reminders app. See the Reminders guide. |
| Productivity Features | AI actions for notes and habits from chat, conversation export, full-text message search, and pinned prompts. See the Productivity guide. |
| Widgets & Notifications | Home-screen widgets and pre-event push notifications. See the Widgets guide. |
| Live Activity & Templates | Dynamic Island / Live Activity during generation, plus conversation templates. See the Templates guide. |
| Settings | Full reference for every setting in the app. See the Settings guide. |
| Privacy | Full explanation of the on-device architecture and what data never leaves your phone. See the Privacy guide. |
| Models | How to download, switch, and manage GGUF models from the app. See the Models guide. |
| Accessibility | VoiceOver support, Dynamic Type, Reduce Motion, and other accessibility features. See the Accessibility guide. |
Quick Start
- Download LucidPal from the App Store and open it.
- Download an AI model — pick the recommended model for your device on the "Choose Your AI" screen and tap Download & Get Started.
- Grant calendar permission — LucidPal will ask during onboarding so it can read and write your events.
- Start chatting — type or tap the mic and ask anything: "What do I have tomorrow?", "Schedule a dentist appointment Friday at 3 pm", or "Clear my Tuesday afternoon."
First-Run Experience
On first launch, LucidPal walks you through five onboarding screens:
| Step | Screen | What happens |
|---|---|---|
| 1 | Your Pocket AI | Overview of on-device, no-cloud design |
| 2 | Knows Your Schedule | Introduction to calendar integration |
| 3 | Type or Speak | Mic and text input introduction |
| 4 | Choose Your AI | Select a text model (required) and an optional vision model, then download |
| 5 | Data Sources | Enable Notes, Habits, Contacts, Calendar, Location, and Web Search. iOS permission prompts for Calendar, Contacts, and Location appear inline so you can grant access in context before entering the app. |
After step 5, you are taken directly into the app with all selected permissions granted.
Device Requirements
LucidPal runs the AI model entirely on-device and requires at least 6 GB of RAM. Devices with less RAM are not supported and will see an informational screen explaining the requirement.
| Device | RAM | Supported |
|---|---|---|
| iPhone 12 Pro / 12 Pro Max | 6 GB | ✅ Yes |
| iPhone 13 series (all models) | 4–6 GB | ✅ Yes (13 Pro/Pro Max have 6 GB) |
| iPhone 14 series and later | 6 GB+ | ✅ Yes |
| iPhone 16 series and later | 8 GB+ | ✅ Yes |
| iPhone 12 / 12 mini | 4 GB | ❌ No |
| iPhone 11 and earlier | ≤4 GB | ❌ No |
The standard iPhone 12 and iPhone 12 mini have only 4 GB of RAM and are not supported, even though they run a compatible iOS version. The iPhone 12 Pro and 12 Pro Max (6 GB) are fully supported.
The minimum iOS version required is iOS 16 (for AppIntents/Siri Shortcuts support). iOS 17 or later is recommended.
Models
LucidPal ships with three GGUF model options, automatically selected based on device RAM:
| Model | Size | Min RAM | Recommended for |
|---|---|---|---|
| Qwen3.5 0.8B | 0.51 GB | 2 GB | Older iPhones with limited RAM |
| Qwen3.5 2B | 1.2 GB | 3 GB | Default — iPhone 12 / 13 and similar |
| Qwen3.5 4B | 2.5 GB | 5 GB | iPhone 14 Pro / 15 / 16 and newer |
All three models run natively via llama.cpp with Metal GPU acceleration.
Tech Stack
| Layer | Technology |
|---|---|
| Language | Swift 5.10 + SwiftUI |
| LLM Runtime | llama.cpp (C FFI via Swift actor) |
| Calendar | EventKit (wrapped in CalendarService) |
| Speech | AVFoundation + SFSpeechRecognizer |
| Vision | llama.cpp multimodal (optional GGUF) |
| Siri | AppIntents framework |
| Persistence | Custom JSON session store |
| Testing | XCTest with full mock infrastructure |