MatrixSynapse

MatrixSynapse, commonly called Synapse, is the reference homeserver implementation for the Matrix decentralized communications protocol. It is an open-source project maintained by the Matrix.org Foundation and a community of contributors. The server is written in Python and exposes the Matrix client-server API and the server-to-server federation interface used to exchange messages with other homeservers.

Core responsibilities include user authentication, room creation and management, event storage, and message routing between local users and remote servers. Synapse implements the Matrix REST and federation endpoints, including client API, identity management, push notifications, and event streams. It can be deployed as a standalone process or scaled using a multi-process worker architecture that separates concerns such as authentication, storage, and federation.

Storage and deployment options: PostgreSQL is the recommended database for production; SQLite may be used for testing or light deployments. Redis can be used for caching and rate limiting. Synapse supports application services for bridging to other platforms and can be configured to run with multiple workers to increase throughput and resilience.

Security and privacy: End-to-end encryption is handled by clients via Olm/Megolm, while Synapse stores encrypted events without decrypting them. The server supports TLS, audit logging, moderation tools, and standard Matrix privacy safeguards.

License and ecosystem: Synapse is released under the Apache 2.0 license and has become the de facto reference server for Matrix. It operates alongside other components of the Matrix ecosystem, such as the Element client, and features ongoing development with improvements in performance, reliability, and security.