celld, a new open-source project from Ryan Dahl (creator of Node.js), offers a self-hosted alternative to Cloudflare's Durable Objects. Unlike Cloudflare's managed solution, celld lets developers maintain application data and state directly on their own servers without vendor lock-in.
Each celld object comes with its own SQLite database and supports persistent WebSocket connections, making it well-suited for real-time applications like chat systems, multiplayer games, and collaborative tools. Data is continuously replicated to S3-compatible storage or Google Cloud Storage buckets, providing durability and backup capabilities.
The implementation covers a substantial portion of the Workers and Durable Objects API surface, easing migration for developers already familiar with Cloudflare's ecosystem. The project is open source and available in the denoland/celld repository on GitHub, allowing the community to contribute, audit, and adapt the technology to their specific needs.