SimpleUX Chat 💬

A personal, UX-first fork of SimpleX Chat - same protocol, same untouched core, an interface I can actually live in every day.

License: AGPL v3 SimpleX Protocol Compatible Coexistence Ready Platforms SimpleUX Frontend CI

SimpleX Chat is a cryptographic masterclass: the first messaging platform with no user identifiers of any kind, end-to-end encryption with post-quantum resistance, and isolated unidirectional messaging queues. It is a project with a lot of potential - and one that deserves far more contributions toward its user interface.

This fork exists because I wanted to live in SimpleX every day, and the interface made that hard. To be blunt: the UX felt dated and unpleasant for daily use - at least, to me.

And to be clear about the ambition: I am not claiming this UI is better - it is not, by far. I am simply implementing, for my own use, the interaction patterns I find pleasant in the messengers I already use every day, so that moving to the SimpleX ecosystem stops feeling like a comfort downgrade. If some of it is useful to you, welcome.

Why a fork instead of pull requests? I would genuinely have preferred to contribute this upstream. But the number of long-open pull requests on the parent project made it obvious that interface changes of this scale would land far too slowly for someone who wants to use the app today, not in a few years. This fork is that impatience made useful.

What moves here: the frontend only (Kotlin Multiplatform / Compose). The authoritative Haskell core engine (libsimplex / libapp) and the JNI/FFI cryptographic bindings stay 100% untouched and fully interoperable with official SimpleX clients.

SimpleUX introduces an elevated visual aesthetic crafted for discretion, clarity, and tactile precision:

• Circular Titanium Discs: Avatars use perfectly circular geometry with a 1.dp hairline specular highlight rim (#26FFFFFF dark / #1A000000 light) for a machined mineral feel.
• Champagne Gold Accents: Key interactive states (active navigation tab, reply indicator, security highlights) use subtle champagne gold (#E2B755 dark / #D97706 light).
• Floating Island Navigation: A 3-tab bottom bar (Chats, Contacts, Settings) floating gracefully over conversational content.
• Authentic Security States: The SecurityBadge dynamically evaluates real double-ratchet post-quantum negotiation (connPQEnabled in both directions) with zero simulated states.

SimpleUX is built from the ground up to coexist peacefully with the official SimpleX app on any device:

• Unique Application ID: Configured as chat.simplex.ux; an optional debug id can be enabled via the application_id.suffix Gradle property (empty by default).
• Isolated Sandboxes: Separate local SQLite databases, keychain groups, and media cache folders.
• Dedicated Content Providers: Uses chat.simplex.ux.provider to prevent any authority collisions.
• Independent Sync Services: Background message notifications run autonomously without interfering with standard SimpleX apps.

SimpleUX preserves the multi-tier architecture of SimpleX, isolating UI/UX advancements strictly to the presentation layer:

┌─────────────────────────────────────────────────────────────────────────┐
│ SimpleUX UI Layer (Compose & SwiftUI) │
│ • Luxury Mineral Tokens (Color, Shape, Typography, Specular Rims) │
│ • Redesigned Views (ChatList, ChatView, ChatInfo, Settings, Contacts) │
│ • Message Actions (Reaction picker, Draft persistence) │
└─────────────────────────────────────────────────────────────────────────┘
 │ ▲さんかく
 User Interactions │ │ StateFlows / Recomposition
 ▼ │
┌─────────────────────────────────────────────────────────────────────────┐
│ Application Logic Layer │
│ • ChatModel (State container) & ChatController (Command dispatcher) │
│ • AppPreferences, NotificationManager, ThemeManager │
└─────────────────────────────────────────────────────────────────────────┘
 │ ▲さんかく
 sendCmd() │ │ recvMsg() / processReceivedMsg()
 ▼ │
┌─────────────────────────────────────────────────────────────────────────┐
│ JNI / C FFI Bridge (Core.kt / C) │
│ • chatSendCmdRetry() / chatRecvMsgWait() │
└─────────────────────────────────────────────────────────────────────────┘
 │ ▲さんかく
 C Foreign Function Interface (FFI)
 ▼ │
┌─────────────────────────────────────────────────────────────────────────┐
│ Haskell Core Engine (libsimplex / libapp) │
│ • Double-Ratchet E2EE, SMP Queues, XFTP File Relays, SQLite DB │
└─────────────────────────────────────────────────────────────────────────┘

Prerequisites: JDK 17-21, Android SDK (API 35), NDK (23.1+), CMake.

# Navigate to the multiplatform project directory
cd apps/multiplatform
# Run all unit and desktop verification tests
./gradlew desktopTest
# Build Android Debug APK (FOSS Flavor)
./gradlew assembleFossDebug
# Build Android Release APK
./gradlew assembleFossRelease
# Package Desktop App for Current OS (Windows MSI/EXE, macOS DMG, Linux DEB)
./gradlew :desktop:packageDistributionForCurrentOS

Add https://github.com/delta-whiplash/simpleUx-chat as a GitHub source in Obtainium. Every build gets its own v*-ux.* tag, so default version detection works — just enable Track prereleases (all builds except explicit stable cuts are prereleases) and filter APKs to arm64-v8a.

Prerequisites: macOS with Xcode 15+, CocoaPods / Swift Package Manager.

cd apps/ios
open SimpleX.xcodeproj

• AGENTS.md - Architectural invariants, coexistence strategy, and guidelines for contributors.
• Design System Skill - Full specification of tokens, colors, shapes, and micro-interaction patterns.
• Upstream Documentation - In-depth specifications of the SMP/XFTP protocols and cryptographic fundamentals.

SimpleUX Chat is an interface fork created with deep respect for the visionary work of Evgeny Poberezkin and the SimpleX Chat core team and open-source contributors.

• Official Upstream Repository: simplex-chat/simplex-chat
• Official SimpleX Website: simplex.chat

This software is licensed under the GNU Affero General Public License version 3 (AGPLv3). See the LICENSE file for details.