SimpleX Chat

SimpleX Chat is an open-source, privacy-first messaging network designed to operate without any user identifiers. It provides mobile, desktop and terminal clients built on a Haskell core, delivering end-to-end encrypted messaging and group/community features while letting operators run their own servers.

Key Features

• Messaging without user identifiers: the network is designed to deliver messages and form connections without persistent numeric or textual user IDs.
• Strong encryption: double-ratchet end-to-end encryption with an additional encryption layer and local database encryption (SQLCipher/SQLite for device storage).
• Haskell core with native UI bridges: a Haskell-based core library exposed to client UIs via FFI, used by Kotlin Multiplatform (Android/desktop) and native iOS (Swift) apps.
• Multiple clients and runtimes: Android (Kotlin Multiplatform), iOS (Swift), desktop builds and a terminal/CLI client for Linux/macOS/Windows.
• Flexible storage backends: SQLite (default for mobile/desktop) and PostgreSQL support for server-side deployments; storage abstraction via a unified store interface.
• Extensible platform: bots API, SDKs and a directory service for discoverable communities and group moderation tools.
• Cross-platform build tooling: builds and cross-compilation support using Cabal/Nix and Docker-based build scripts, with prebuilt packages distributed via Play Store, F‑Droid, TestFlight and direct APKs.

Use Cases

• Private one-to-one messaging and group conversations where participants do not want persistent user identifiers.
• Community-run groups and moderated communities using the SimpleX directory and community voucher model for server funding.
• Developers building bots, automations or integrations using the provided bots API and client SDKs.

Limitations and Considerations

• Platform/build complexity: the Haskell core and cross-compilation workflow make local builds more involved than typical native apps; building from source normally requires Haskell tooling, Nix or Docker images.
• Mobile support constraints: historically builds targeted newer Android versions and specific CPU architectures; current official builds require modern mobile OS versions (Android 8+ minimum is documented) and some legacy devices may need experimental APKs.

SimpleX Chat is focused on strong privacy guarantees, decentralization and developer extensibility. It is suited for users and communities that require encrypted messaging without traditional identifiers and for developers who want to build bots or host community servers.