SimpleX Chat multiplatform product specification (Android + Desktop). Bidirectional code links: product docs reference source files, source files reference product docs.

Related spec: spec/README.md | spec/architecture.md

Executive Summary
Vision
Target Users
Capability Map
Navigation Map
Related Specifications

Executive Summary

SimpleX Chat is the first messaging platform with no user identifiers of any kind -- not even random numbers. It provides end-to-end encrypted messaging (with optional post-quantum cryptography), audio/video calls, file sharing, and group communication through a fully decentralized architecture where users control their own SMP relay servers.

The Android and Desktop apps share a single Kotlin Multiplatform + Compose Multiplatform codebase. Common UI and business logic lives in a shared common/ module, while platform-specific behavior (notifications, audio, video playback, file system access, call management) is abstracted through the Kotlin expect/actual pattern and a runtime PlatformInterface delegate. The Haskell core library is loaded via JNI (external fun declarations in Core.kt), exposing the full SimpleX Chat API (message send/receive, encryption, migration, file handling) through native FFI.

Key platform differences:

Android uses a 2-column layout (AndroidScreen): chat list slides to chat view. Background messaging is handled by SimplexService (foreground service) + MessagesFetcherWorker (WorkManager periodic fetch). Calls use a dedicated CallService + CallActivity.
Desktop uses a 3-column layout (DesktopScreen): chat list (start) | chat view (center) | detail panel (ModalManager.end). It includes AppUpdater for in-app update checking, StoreWindowState for window geometry persistence, and VLC-based video playback. Calls use browser-based WebRTC rendered inline.

Vision

SimpleX Chat is the first messaging platform that has no user identifiers -- not even random numbers. It uses double-ratchet end-to-end encryption with optional post-quantum cryptography. The system is fully decentralized with user-controlled SMP relay servers.

The protocol design ensures that no server or network observer can determine who communicates with whom. Each conversation uses separate unidirectional messaging queues on potentially different servers, and there is no shared identifier between the sender and receiver queues.

Target Users

Privacy-conscious individuals wanting secure messaging without phone-number or email-based identity
Groups and communities needing encrypted group communication with role-based access control
Users avoiding identity linkage who want to communicate without any persistent user identifier
Organizations needing self-hosted messaging infrastructure with full control over relay servers
Desktop users wanting a native desktop client with the same privacy guarantees as the mobile app

Capability Map

All source paths below are relative to apps/multiplatform/. The common source root is common/src/commonMain/kotlin/chat/simplex/common/.

1. Messaging

Core message composition, delivery, and interaction features.

Feature	Description	Key Source (Kotlin)
Text with markdown	Rich text formatting with SimpleX markdown syntax	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ComposeView.kt`
Images	Compressed inline images with full-screen gallery	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIImageView.kt`
Video	Video message recording and playback	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIVideoView.kt`
Voice messages	Audio recording and playback (5min / 510KB limit)	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIVoiceView.kt`
File sharing	Files up to 1GB via XFTP protocol	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIFileView.kt`
Link previews	OpenGraph metadata extraction and display	`common/src/commonMain/kotlin/chat/simplex/common/views/helpers/LinkPreviews.kt`
Message reactions	Emoji reactions on sent/received messages	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/EmojiItemView.kt`
Message editing	Edit previously sent messages	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ComposeView.kt`
Message deletion	Broadcast delete (for recipient) or internal-only delete	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/MarkedDeletedItemView.kt`
Timed messages	Self-destructing messages with configurable TTL	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIChatFeatureView.kt`
Quoted replies	Reply to specific messages with quote context	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ContextItemView.kt`
Forwarding	Forward messages between chats	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ComposeView.kt`
Search	Full-text search within conversations	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatView.kt`
Message reports	Report messages to group moderators	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupReportsView.kt`
Send message bar	Composable message input with attachments, voice, send button	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/SendMsgView.kt`

2. Contacts

Establishing, managing, and verifying contacts.

Feature	Description	Key Source (Kotlin)
Add via SimpleX address	Connect using a SimpleX contact address	`common/src/commonMain/kotlin/chat/simplex/common/views/newchat/NewChatView.kt`
Add via QR code	Scan QR code to establish connection	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ScanCodeView.kt`
Contact requests	Accept or reject incoming contact requests	`common/src/commonMain/kotlin/chat/simplex/common/views/chatlist/ContactRequestView.kt`
Local aliases	Set private display names for contacts	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatInfoView.kt`
Contact verification	Compare security codes out-of-band	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/VerifyCodeView.kt`
Blocking	Block contacts from sending messages	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatInfoView.kt`
Incognito mode	Per-contact random profile generation	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/IncognitoView.kt`
Bot detection	Identify automated/bot contacts	`common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt`
Contact list	Dedicated contact browsing view	`common/src/commonMain/kotlin/chat/simplex/common/views/contacts/ContactListNavView.kt`

3. Groups

Multi-party encrypted conversations with role-based management.

Feature	Description	Key Source (Kotlin)
Create groups	Create new group with initial members	`common/src/commonMain/kotlin/chat/simplex/common/views/newchat/AddGroupView.kt`
Invite members	Invite by individual contact or link	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/AddGroupMembersView.kt`
Member roles	Owner, admin, moderator, member, observer	`common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt`
Member admission	Queue-based admission with review workflow	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/MemberAdmission.kt`
Group links	Shareable invite links for groups	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupLinkView.kt`
Business chat mode	Structured business communication groups	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupChatInfoView.kt`
Content moderation	Member reports and moderator actions	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/MemberSupportView.kt`
Group preferences	Configure group-level feature settings	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupPreferences.kt`
Member direct contacts	Establish direct chats from group membership	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupMemberInfoView.kt`
Group mentions	@-mention members in group messages	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupMentions.kt`
Welcome message	Custom welcome message for new group members	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/WelcomeMessageView.kt`
Group profile	Edit group name, image, description	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupProfileView.kt`
Member support chat	Scoped support threads between members and admins	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/MemberSupportChatView.kt`

4. Calling

End-to-end encrypted audio and video communication.

Feature	Description	Key Source (Kotlin)
E2E encrypted calls	Audio/video calls via WebRTC with E2E encryption	`common/src/commonMain/kotlin/chat/simplex/common/views/call/WebRTC.kt`
Call manager	Call state machine and lifecycle management	`common/src/commonMain/kotlin/chat/simplex/common/views/call/CallManager.kt`
Call history	Call events displayed as chat items	`common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CICallItemView.kt`
Incoming call view	Dedicated UI for incoming call notifications	`common/src/commonMain/kotlin/chat/simplex/common/views/call/IncomingCallAlertView.kt`
Android CallService	Foreground service for active calls on Android	`android/src/main/java/chat/simplex/app/CallService.kt`
Android CallActivity	Dedicated Activity for call UI on Android	`android/src/main/java/chat/simplex/app/views/call/CallActivity.kt`
Desktop inline calls	Browser-based WebRTC rendered inline in desktop window	`common/src/commonMain/kotlin/chat/simplex/common/views/call/CallView.kt`

5. Privacy & Security

Encryption, authentication, and privacy controls.

Feature	Description	Key Source (Kotlin)
E2E encryption	Double-ratchet encryption for all messages	`common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt`
Post-quantum encryption	Optional PQ key exchange for direct chats	`common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt`
Local authentication	Biometric (fingerprint/face) or app passcode lock	`common/src/commonMain/kotlin/chat/simplex/common/views/localauth/LocalAuthView.kt`
Passcode entry	Custom numeric/alphanumeric passcode UI	`common/src/commonMain/kotlin/chat/simplex/common/views/localauth/PasscodeView.kt`
Hidden profiles	Password-protected profiles invisible in UI	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/HiddenProfileView.kt`
Database encryption	AES encryption of local SQLite database	`common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseEncryptionView.kt`
Screen privacy	Blur/hide app content when in app switcher	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/PrivacySettings.kt`
Encrypted file storage	Local files encrypted at rest	`common/src/commonMain/kotlin/chat/simplex/common/model/CryptoFile.kt`
Delivery receipts control	Toggle delivery/read receipts per contact/group	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/SetDeliveryReceiptsView.kt`
App lock	Automatic lock on background/timeout with configurable delay	`common/src/commonMain/kotlin/chat/simplex/common/AppLock.kt`

6. User Management

Multiple profiles and identity management.

Feature	Description	Key Source (Kotlin)
Multiple profiles	Multiple user profiles within one app	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/UserProfilesView.kt`
Active user switching	Switch between profiles via user picker	`common/src/commonMain/kotlin/chat/simplex/common/views/chatlist/UserPicker.kt`
Incognito contacts	Per-contact random identities	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/IncognitoView.kt`
Profile sharing	Share profile via contact address link	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/UserAddressView.kt`
User muting	Mute notifications for specific profiles	`common/src/commonMain/kotlin/chat/simplex/common/views/chatlist/UserPicker.kt`
User profile editing	Edit display name and profile image	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/UserProfileView.kt`

7. Network

Server configuration, proxy support, and connectivity.

Feature	Description	Key Source (Kotlin)
Custom SMP servers	Configure personal SMP relay servers	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/ProtocolServersView.kt`
Custom XFTP servers	Configure personal XFTP file servers	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/ProtocolServersView.kt`
Tor/onion support	Route traffic through Tor .onion addresses	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/AdvancedNetworkSettings.kt`
SOCKS5 proxy	Route connections through SOCKS5 proxy	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/AdvancedNetworkSettings.kt`
Custom ICE servers	Configure WebRTC ICE/TURN servers	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/RTCServers.kt`
Network timeouts	Configure connection timeout parameters	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/AdvancedNetworkSettings.kt`
Server operators	Configure and manage SMP/XFTP server operators	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/OperatorView.kt`
Server status	View aggregate server connectivity status	`common/src/commonMain/kotlin/chat/simplex/common/views/chatlist/ServersSummaryView.kt`
Network & servers hub	Central network configuration entry point	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/networkAndServers/NetworkAndServers.kt`

8. Customization

Visual appearance and UI preferences.

Feature	Description	Key Source (Kotlin)
Themes	Light, dark, SimpleX, black, and custom themes	`common/src/commonMain/kotlin/chat/simplex/common/ui/theme/ThemeManager.kt`
Wallpapers	Preset and custom chat wallpapers	`common/src/commonMain/kotlin/chat/simplex/common/views/helpers/ChatWallpaper.kt`
Chat bubble styling	Customize message bubble appearance	`common/src/commonMain/kotlin/chat/simplex/common/ui/theme/Theme.kt`
One-handed UI mode	Compact layout for single-hand use (Android)	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/Appearance.kt`
Language selection	In-app language override	`common/src/commonMain/kotlin/chat/simplex/common/views/usersettings/Appearance.kt`
Theme mode editor	Interactive theme color and mode customization	`common/src/commonMain/kotlin/chat/simplex/common/views/helpers/ThemeModeEditor.kt`

9. Data Management

Import, export, encryption, and storage management.

Feature	Description	Key Source (Kotlin)
Export/import profiles	Full database export and import	`common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseView.kt`
Database encryption	Encrypt/decrypt local database with passphrase	`common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseEncryptionView.kt`
Local file encryption	Encrypt stored media and attachments	`common/src/commonMain/kotlin/chat/simplex/common/model/CryptoFile.kt`
Database error handling	Recovery UI for database migration failures	`common/src/commonMain/kotlin/chat/simplex/common/views/database/DatabaseErrorView.kt`
Device-to-device migration	Migrate full profile between devices	`common/src/commonMain/kotlin/chat/simplex/common/views/migration/MigrateFromDevice.kt`
Receive migration	Accept incoming device migration transfer	`common/src/commonMain/kotlin/chat/simplex/common/views/migration/MigrateToDevice.kt`
Database utilities	Key storage, password management, helper functions	`common/src/commonMain/kotlin/chat/simplex/common/views/helpers/DatabaseUtils.kt`

10. Desktop Features

Desktop-specific functionality not present on Android.

Feature	Description	Key Source (Kotlin)
3-column layout	Start (chat list) / center (chat) / end (detail) panels	`common/src/commonMain/kotlin/chat/simplex/common/App.kt` (`DesktopScreen`)
ModalManager.end	Third-column detail panel for settings/info views	`common/src/commonMain/kotlin/chat/simplex/common/views/helpers/ModalView.kt` (`ModalManager`)
App update checker	In-app notification for available updates	`common/src/desktopMain/kotlin/chat/simplex/common/views/helpers/AppUpdater.kt`
Window state persistence	Save/restore window position and dimensions	`common/src/desktopMain/kotlin/chat/simplex/common/StoreWindowState.kt`
VLC video playback	Desktop video playback via VLC native libraries	`common/src/desktopMain/kotlin/chat/simplex/common/platform/VideoPlayer.desktop.kt`
Desktop app entry	Main function, Haskell init, VLC loading	`desktop/src/jvmMain/kotlin/chat/simplex/desktop/Main.kt`
Desktop notification manager	Platform-native desktop notifications	`common/src/desktopMain/kotlin/chat/simplex/common/platform/Notifications.desktop.kt`
Connect mobile device	Pair desktop with a mobile device for remote access	`common/src/commonMain/kotlin/chat/simplex/common/views/remote/ConnectMobileView.kt`
Desktop platform abstraction	Desktop-specific PlatformInterface implementation	`common/src/desktopMain/kotlin/chat/simplex/common/platform/AppCommon.desktop.kt`
Desktop app shell	Compose Desktop window, theming, lifecycle	`common/src/desktopMain/kotlin/chat/simplex/common/DesktopApp.kt`

Onboarding
  views/onboarding/SimpleXInfo.kt
    -> SimpleXInfo -> CreateFirstProfile -> SetupDatabasePassphrase
    -> ChooseServerOperators -> SetNotificationsMode
    -> ChatListView (home)

ChatListView (home)
  views/chatlist/ChatListView.kt
    -> ChatView .................. (tap conversation row, slides in)
    -> NewChatSheet .............. (+ FAB button)
    -> SettingsView .............. (gear icon)
    -> UserPicker ................ (avatar tap)
    -> TagListView ............... (tag filter bar)
    -> ServersSummaryView ........ (server status indicator)
    -> ShareListView ............. (share intent from external apps)
    -> ChatHelpView .............. (empty state help)

ChatView
  views/chat/ChatView.kt
    -> ChatInfoView .............. (contact name tap, direct chat)
    -> GroupChatInfoView ......... (group name tap, group chat)
    -> ActiveCallView ............ (call button, launches CallActivity)
    -> ComposeView ............... (message input area)
    -> ChatItemInfoView .......... (long press -> info)
    -> MemberSupportChatView ..... (member support thread)
    -> ScanCodeView .............. (scan QR)
    -> CommandsMenuView .......... (/ commands)

ChatInfoView
  views/chat/ChatInfoView.kt
    -> ContactPreferences ........ (preferences)
    -> VerifyCodeView ............ (verify security code)

GroupChatInfoView
  views/chat/group/GroupChatInfoView.kt
    -> GroupProfileView .......... (edit profile)
    -> AddGroupMembersView ....... (invite members)
    -> GroupLinkView ............. (manage group link)
    -> MemberAdmission ........... (admission settings)
    -> GroupPreferences .......... (group feature settings)
    -> GroupMemberInfoView ....... (tap member)
    -> WelcomeMessageView ........ (welcome message)
    -> GroupReportsView .......... (view reports)

NewChatSheet
  views/newchat/NewChatSheet.kt
    -> NewChatView ............... (QR scanner / paste link)
    -> AddGroupView .............. (create group)
    -> UserAddressView ........... (create SimpleX address)

SettingsView
  views/usersettings/SettingsView.kt
    -> AppearanceView ............ (themes, wallpapers, UI)
    -> NetworkAndServers ......... (SMP/XFTP/proxy config)
    -> PrivacySettings ........... (privacy toggles)
    -> NotificationsSettingsView . (notification mode)
    -> DatabaseView .............. (export/import/encrypt)
    -> CallSettings .............. (call preferences)
    -> VersionInfoView ........... (about/version)
    -> DeveloperView ............. (developer options)
    -> HelpView .................. (help & support)

UserPicker
  views/chatlist/UserPicker.kt
    -> UserProfilesView .......... (manage all profiles)
    -> UserAddressView ........... (SimpleX address)
    -> Preferences ............... (user preferences)
    -> SettingsView .............. (app settings)
    -> ConnectDesktopView ........ (pair with desktop)

+---------------------------+----------------------------------+----------------------------+
|     START PANEL           |        CENTER PANEL              |       END PANEL            |
|  (DEFAULT_START_MODAL_    |   (flexible width, min           |  (DEFAULT_END_MODAL_       |
|   WIDTH)                  |    DEFAULT_MIN_CENTER_MODAL_     |   WIDTH)                   |
|                           |    WIDTH)                        |                            |
+---------------------------+----------------------------------+----------------------------+
|                           |                                  |                            |
|  ChatListView             |  ChatView                        |  ChatInfoView              |
|    - chat rows            |    - message list                |  GroupChatInfoView         |
|    - search               |    - ComposeView                 |  GroupMemberInfoView       |
|    - tag filters          |    - media viewer                |  ContactPreferences        |
|    - server status        |                                  |  GroupPreferences          |
|                           |  OR (when no chat selected):     |  GroupProfileView          |
|  UserPicker (overlay)     |    "No selected chat"            |  AddGroupMembersView       |
|    - profile switcher     |                                  |  MemberAdmission           |
|    - quick settings       |  OR (when modal open):           |  VerifyCodeView            |
|                           |    ModalManager.center content   |  SettingsView subtabs      |
|  ModalManager.start       |    (settings, new chat, etc.)    |                            |
|    - secondary modals     |                                  |  ModalManager.end          |
|                           |                                  |    - detail modals         |
+---------------------------+----------------------------------+----------------------------+

ModalManager Placement (Desktop):
  - ModalManager.start  -> left panel overlay (settings subviews)
  - ModalManager.center -> center panel (replaces chat, used when chatId is null)
  - ModalManager.end    -> right panel (detail/info views)
  - ModalManager.fullscreen -> full window overlay (onboarding, auth, call)

On Android, all ModalManager instances (start/center/end/fullscreen) collapse to a
single shared ModalManager that presents modals as full-screen overlays.

Desktop-only navigation targets:
  ConnectMobileView ......... (pair with mobile device)
  AppUpdater notice ......... (update available notification)
  Floating terminal ......... (developer console)
  ActiveCallView ............ (inline WebRTC call, not separate Activity)

Platform Abstraction

The codebase uses two mechanisms for platform-specific behavior:

1. `expect`/`actual` Declarations

Kotlin Multiplatform expect declarations in common/src/commonMain/kotlin/chat/simplex/common/platform/ with corresponding actual implementations in:

common/src/androidMain/kotlin/chat/simplex/common/platform/*.android.kt
common/src/desktopMain/kotlin/chat/simplex/common/platform/*.desktop.kt

Key expect/actual abstractions: appPlatform, BackHandler, VideoPlayer, AudioPlayer, RecorderNative, NtfManager, showToast, getKeyboardState, PlatformTextField, image processing, file sharing, and more.

2. Runtime `PlatformInterface`

Defined in common/src/commonMain/kotlin/chat/simplex/common/platform/Platform.kt, this interface provides platform-specific callbacks that cannot use expect/actual (because android/ module code cannot be called from common/androidMain/). The platform variable is reassigned at app startup:

Android: SimplexApp sets platform to an implementation with CallService, notification channels, orientation locking, status bar theming, and PiP support.
Desktop: Main.kt sets platform to an implementation with desktopShowAppUpdateNotice().

3. Haskell Core (JNI/FFI)

Native FFI bindings are declared in common/src/commonMain/kotlin/chat/simplex/common/platform/Core.kt as external fun declarations. These include: chatMigrateInit, chatSendCmdRetry, chatRecvMsg, chatParseMarkdown, chatPasswordHash, chatWriteFile, chatReadFile, chatEncryptFile, chatDecryptFile, and more. The native library (libapp-lib) is loaded at startup from platform-specific resource directories.

Background Messaging (Android)

Android has no equivalent to iOS NSE (Notification Service Extension). Instead, it uses:

SimplexService (android/src/main/java/chat/simplex/app/SimplexService.kt) -- A foreground service that keeps the Haskell core running to receive messages in real-time. Displays a persistent notification while active.
MessagesFetcherWorker (android/src/main/java/chat/simplex/app/MessagesFetcherWorker.kt) -- A WorkManager-based periodic task that wakes the app at configurable intervals to fetch messages when the foreground service is not running (battery-optimized mode).
Notification modes: Instant (foreground service always running), Periodic (WorkManager fetch every N minutes), Off.

Product Layer (this directory)

concepts.md -- Feature concept index with bidirectional code links
glossary.md -- Terminology definitions
rules.md -- Business rules and constraints
gaps.md -- Known documentation gaps
Views: chat-list, chat, new-chat, settings, call, contact-info, group-info, onboarding, user-profiles
Flows: messaging, calling, onboarding, group-lifecycle, connection, file-transfer

Spec Layer

spec/README.md -- Technical specification overview
spec/architecture.md -- JNI bridge, startup, lifecycle
spec/state.md -- ChatModel, ChatsContext, Chat, AppPreferences
spec/api.md -- Command/response protocol (CC, CR, ChatError)
spec/database.md -- Migration, encryption, export/import
Client: navigation, chat-list, chat-view, compose
Services: calls, theme, files, notifications

Source Entry Points

Haskell core: ../../src/Simplex/Chat/Controller.hs, ../../src/Simplex/Chat/Types.hs
Kotlin model: common/src/commonMain/kotlin/chat/simplex/common/model/ChatModel.kt
Kotlin API bridge: common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt
Kotlin FFI: common/src/commonMain/kotlin/chat/simplex/common/platform/Core.kt
Android entry: android/src/main/java/chat/simplex/app/SimplexApp.kt, MainActivity.kt
Desktop entry: desktop/src/jvmMain/kotlin/chat/simplex/desktop/Main.kt

README.md

SimpleX Chat Android & Desktop -- Product Overview

Table of Contents

Executive Summary

Vision

Target Users

Capability Map

1. Messaging

2. Contacts

3. Groups

4. Calling

5. Privacy & Security

6. User Management

7. Network

8. Customization

9. Data Management

10. Desktop Features

Navigation Map

Android Navigation (2-column slide)

Desktop Navigation (3-column panels)

Platform Abstraction

1. `expect`/`actual` Declarations

2. Runtime `PlatformInterface`

3. Haskell Core (JNI/FFI)

Background Messaging (Android)

Product Layer (this directory)

Spec Layer

Source Entry Points

README.md

SimpleX Chat Android & Desktop -- Product Overview

Table of Contents

Executive Summary

Vision

Target Users

Capability Map

1. Messaging

2. Contacts

3. Groups

4. Calling

5. Privacy & Security

6. User Management

7. Network

8. Customization

9. Data Management

10. Desktop Features

Navigation Map

Android Navigation (2-column slide)

Desktop Navigation (3-column panels)

Platform Abstraction

1. expect/actual Declarations

2. Runtime PlatformInterface

3. Haskell Core (JNI/FFI)

Background Messaging (Android)

Related Specifications

Product Layer (this directory)

Spec Layer

Source Entry Points

1. `expect`/`actual` Declarations

2. Runtime `PlatformInterface`