openmls/openmls

Health v2 · maintenance only

Adoption not part of the score

1022 stars · 175 forks observed · 2026-09-03

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

OpenMLS is a Rust implementation of the Messaging Layer Security (MLS) protocol as specified in RFC 9420. It is a library providing safe, easy-to-use end-to-end encryption for group messaging, with pluggable cryptographic backends and support for targets including Linux, Windows, macOS, Android, iOS, and WebAssembly.

Use cases

• add end-to-end encrypted group messaging to an app
• implement the MLS protocol (RFC 9420) in Rust
• encrypt messages for groups of two to many participants
• build a secure messaging library with pluggable crypto backends
• compile E2EE messaging code to WebAssembly or mobile platforms
• resolve group state forks in MLS-based messaging

When to choose

• you need a standards-compliant MLS (RFC 9420) implementation
• you want safe, memory-safe Rust code for E2EE group messaging
• you need cross-platform support including mobile and WASM
• you want to bring your own cryptographic provider via traits

When to avoid

• you need a complete messaging application rather than a protocol library
• you need a non-Rust language implementation without FFI/wasm compilation
• you require cryptographic primitives implemented in the library itself (it delegates to external providers)

Facets

library · maturity active

cryptography security sdk security privacy windows wasm rust cross-platform mls rfc9420 e2ee end-to-end-encryption group-messaging ietf messaging-layer-security messaging linux macos android ios

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