AstralNotes is a modern, high-performance note-taking and personal knowledge app built with Jetpack Compose, Material 3 Expressive design, local Room database persistence, Google Gemini AI intelligence, and optional Firebase Cloud Sync.
- Material 3 Expressive Design - Fluid adaptive layouts, custom pastel note tints, contrast-optimized dark and light modes, and Google Keep-style ease of use.
- Full Markdown Editor - Live interactive checklists, code blocks with 1-tap copy, headers, bold, italic, strikethrough, highlights, and automatic list continuations.
- Biometric Private Vault - Secure confidential and sensitive notes behind biometric fingerprint or custom alphanumeric PIN.
- User-Provided Gemini AI Intelligence - Instant note summarization, action item extraction, creative brainstorming, and interactive conversational chat across your entire knowledge base.
- Offline-First Persistence - All notes persist instantly in a local AndroidX Room SQLite database with zero internet connection required.
- Cloud Sync with Firestore - Real-time bidirectional note synchronization when signed in with Google.
- Tags & Organization - Flexible tag filters, pinned notes, archive storage, and trash recovery.
- Multi-Format Export - Export notes to Markdown (.md), Plain Text (.txt), HTML (.html), or JSON backup.
- Home Screen Quick Note Widget - Capture quick thoughts, checklists, images, and launch AI assistance directly from your Android home screen.
- Download the latest
AstralNotes-Release-APKfrom the Releases or GitHub Actions build artifacts. - Install the
.apkfile on your Android device (Android 8.0 / API 24 or higher). - Open AstralNotes.
AstralNotes operates with 100% user-owned API keys. No developer or server-side API key is bundled or required.
- Obtain a free API key from Google AI Studio.
- In AstralNotes, open the navigation drawer and tap Settings (or tap the Sparkle icon on any note).
- Under Google Gemini Intelligence, paste your key into Custom Gemini API Key.
- (Optional) Select your preferred model (such as
gemini-3.7-flash,gemini-3.5-flash, or enable High Thinking Mode). - Tap Save Gemini Config.
Note: Your API key is stored securely on your local device in private encrypted app storage and is never uploaded or shared.
Offline-First Mode (Default):
- You can use AstralNotes entirely offline without creating an account. All notes persist in your local SQLite Room database.
Cloud Sync Mode:
- Open Settings > Cloud Sync & Firebase Auth.
- Tap Sign In with Google.
- Your notes will automatically sync bidirectionally with your private Cloud Firestore database across your devices.
- Checklists: Type
- [ ]to start an interactive checklist. Tapping Enter on a checked or unchecked item automatically continues the list. - Code Blocks: Wrap code in triple backticks with a language name (e.g.
```kotlin) to get syntax-styled code cards with 1-tap copy. - Locking Notes: Tap the 3-dot menu on any note and select Lock Note to move it into your Biometric Vault.
- AI Chat: Tap the Sparkle icon on any note to summarize, polish, or ask questions about that specific note or your entire library.
- Local Storage: All notes are saved locally on your device in an isolated Room SQLite database.
- Vault Protection: Locked notes require your custom PIN or fingerprint biometric authentication to access and are hidden from regular note lists.
- Private Cloud Data: When Cloud Sync is active, Firestore security rules ensure that only your authenticated Google account can read and write to
users/{userId}/notes. - Zero Third-Party Tracking: No advertising SDKs, trackers, or hidden analytics.
- Developer Knowledge Base: Store markdown documentation, code snippets, and checklists with syntax formatting.
- Meeting & Lecture Notes: Quickly capture ideas and use Gemini AI to generate executive summaries and extract action items.
- Personal Journal & Vault: Keep private journals, passphrases, and sensitive information protected behind biometric security.
- Project Task Tracker: Manage daily to-do lists, grocery lists, and project milestones with live interactive checkboxes.
Google Sign-In fails or shows developer error?
- Verify that your Firebase project has Google provider enabled in Authentication and has your app's SHA-1 certificate fingerprint registered in Project Settings.
Gemini AI returns an authentication error?
- Check that you entered a valid API key from Google AI Studio in Settings > Google Gemini Intelligence.
Want to build from source or contribute?
- UI Framework: Jetpack Compose (Material 3 Expressive)
- Language: Kotlin 2.2
- Architecture: MVVM + Clean Architecture + Offline-First Coroutine Flows
- Local Database: AndroidX Room 2.7 (SQLite / KSP)
- Cloud Backend: Google Cloud Firestore + Firebase Authentication (Credential Manager)
- AI Integration: Google Gemini REST API v1beta
- Image Loading: Coil 2.7
- Security: AndroidX BiometricPrompt + Android Keystore
- Widgets: Android AppWidgetProvider + RemoteViews
- Clone the repository:
git clone https://github.com/editinghero/AstralNotes-Android.git cd AstralNotes-Android - Open in Android Studio Meerkat / Ladybug or newer with JDK 21.
- Sync Gradle and run on an Android device or emulator.
To compile and package the release APK:
./gradlew assembleReleaseThe resulting signed APK will be located at:
app/build/outputs/apk/release/app-release.apk
- Create a Firebase project at Firebase Console.
- Add an Android app with package name
com.astralquarks.notes. - Add the project SHA-1 fingerprint
- Download
google-services.jsonand place it in theapp/folder. - Enable Authentication > Google Sign-In and create a Firestore Database with the security rules in
SETUP.md.
com.astralquarks.notes/
ai/ Gemini AI REST API integration, action parsers, and prompt engineering
auth/ Firebase Authentication and Firestore sync manager
db/ Room Database, DAO queries, and JSON type converters
markdown/ Markdown AST parser, live formatting toolbar, and renderer
model/ Data models (Note, NoteColor, AiChatMessage)
repository/ Offline-first data repository with Room and Cloud reconciliation
security/ BiometricPrompt and custom PIN vault manager
ui/
components/ Bottom dock, note cards, markdown editor, AI sheet, dialogs
screens/ Home, Edit, Vault, Archive, Trash, Tags, Settings, Dashboard
theme/ Material 3 Expressive theme, typography, and pastel palettes
util/ Multi-format exporter (MD, TXT, HTML, JSON) and Catbox uploader
viewmodel/ StateFlow UI viewmodels and event handlers
widget/ Home Screen App Widget provider
Built with ❤️ for productive thinkers and developers