deepstream is an open realtime server that enables clients and backend services to sync data, send messages, and make remote procedure calls at high speed and scale.
The tool addresses the need for low-latency bidirectional communication in applications requiring live data synchronization. It provides three core primitives: records, which are schema-less persistent documents that synchronize changes across all connected clients in milliseconds; events, which enable high-performance publish-subscribe messaging with topic-based routing; and remote procedure calls, which handle request-response workflows with built-in load-balancing and failover. The server also includes authentication mechanisms and a permission language called Valve for controlling which users can perform which actions on which data.
The project suits applications that require real-time data synchronization across multiple clients and services, such as collaborative tools, live dashboards, or trading systems. It is particularly valuable when you need sub-millisecond synchronization of relational data structures and many-to-many messaging patterns. Teams should adopt it if they want to avoid building custom WebSocket infrastructure and need built-in support for authentication, permissions, and request routing at scale.
The project maintains an active development cycle with regular commits across its TypeScript codebase. The maintainers provide comprehensive testing infrastructure including unit tests and an extensive end-to-end testing framework that contributors are expected to run for substantial changes. The project welcomes contributions from developers interested in building performant Node.js applications, with a straightforward setup requiring only Node.js and TypeScript. The team supports binary compilation for production use through packaging scripts, though this requires the standard node-gyp build environment and is only tested against the latest LTS Node.js version.
