Ryan Dahl released celld, an open-source self-hosted alternative to Cloudflare Durable Objects. The newsletter explains what durable objects are: a worker process paired with a local SQLite database and replicated off-machine storage (S3, R2, etc.), where writes are confirmed only after replication so state survives crashes. Celld uses the same API as Cloudflare's Durable Objects and works with wrangler, but is designed to run on any cloud platform. The issue also covers Convex's $57M Series B, Mojo 1.0 release, a JavaScript bug puzzle about a flawed `once()` function, and a roundup of links including CSS text-stroke, LLM programming language benchmarks, and the end of the no-code era.
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The Main ThingOur Friends (With Benefits)Spot the BugCool BitsSpot the Bug: SolutionQuestions this post answers
How do Cloudflare Durable Objects work under the hood?
A Durable Object combines a worker process, a local SQLite database, and replicated off-machine storage (like S3 or R2). Writes are not confirmed until they are replicated to off-machine storage, so if the worker process dies, the state can be restored from the write-ahead log (WAL). This lets the worker stop, start, or move without losing data. Developers building stateful edge services track Durable Objects patterns and alternatives on daily.dev.
What is celld and how does it differ from Cloudflare Durable Objects?
Celld is an open-source, self-hosted implementation of the Durable Objects pattern released by Ryan Dahl. It uses the same API as Cloudflare's Durable Objects and works with the wrangler CLI, but its components are designed to run on any cloud platform. Each cell has its own SQLite database and worker process, with WAL-based replication to object storage such as S3 or R2. Teams evaluating self-hosted stateful compute options find emerging projects like celld covered on daily.dev.