Ryan Dahl releases celld to self-host Durable Objects

Ryan Dahl, the creator of Node.js and Deno, has released celld, an open-source daemon designed to allow users to self-host Cloudflare-style Workers and Durable Objects on their own servers. Released under the Apache 2.0 license, celld replicates the functionality of Cloudflare’s Durable Objects—which provide stateful capabilities to serverless models via individual SQLite databases—using Rust and an S3-compatible bucket for coordination.

The project aims to significantly reduce costs for high-scale deployments. According to comparisons, hosting 100 active cells via celld could cost approximately 43 euros per month, whereas the equivalent service on Cloudflare is estimated at around 361 euros. The cost efficiency is expected to scale, potentially offering savings of over eightyfold at much larger volumes.

Technically, celld avoids complex consensus protocols or failure detectors by using atomic write operations within an S3 bucket to manage cell ownership. It utilizes the Litestream replication format to sync SQLite states. The project is described as a “love letter” to Cloudflare’s Kenton Varda, acknowledging the original concept of Durable Objects.