Signal-Server is a backend messaging infrastructure that powers the Signal Private Messenger applications across Android, Desktop, and iOS platforms.
The server handles the core infrastructure needs of a privacy-focused messaging system, managing user accounts, message routing, and the cryptographic protocols that enable end-to-end encrypted communication. It uses FoundationDB as its data store, which provides the distributed database foundation required for reliable message delivery and state management across a large-scale messaging network.
Organizations deploying Signal-Server should understand that this is infrastructure for running a complete messaging service, not a library or SDK for embedding messaging into other applications. The project is suitable for operators who want to run their own Signal-compatible messaging infrastructure and have the operational expertise to manage a distributed system. The README directs users to an unofficial community forum for technical support rather than offering direct support channels, indicating this is positioned for self-sufficient deployments. Protocol documentation is available separately on the Signal website for developers integrating with the system.
Development activity shows consistent engagement with security practices, including a dedicated security contact for vulnerability reporting. The project maintains active build and testing infrastructure, with FoundationDB client library integration as a core requirement. The codebase is written in Java and remains under active maintenance to support the three client platforms it serves.
