Deno joins Cloudflare as workerd and celld merge to simplify self-hosting
The Deno team is joining Cloudflare, which plans to merge workerd and celld to make self-hosting Workers and Durable Objects simpler, per an Oct 9, 2026 post.
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The Deno team is joining Cloudflare, and the two companies plan to merge workerd and celld, according to a Cloudflare blog post published October 9, 2026. The stated goal is to radically simplify self-hosting Workers and Durable Objects so developers can use the same primitives in more places.
The post is credited to Ryan Dahl, Senior Principal Engineer at Cloudflare and founder of Deno, and Kenton Varda, Distinguished Engineer. Dahl writes that he is “merging workerd and celld” and points readers to his own post on the Deno blog for details on what happens to the Deno runtime.
Why Durable Objects became the target
Dahl traces the decision back to Node.js and Deno. He describes Node.js as an exploration of a purely asynchronous programming model, and says that with Deno “we improved the experience of writing JavaScript, but we didn’t fundamentally change what developers had to assemble around the runtime.” The harder problems, in his framing, are networked applications: distributing computation, coordinating state, data storage and autoscaling.
He writes that the solution clicked into focus when he read about Cloudflare’s Durable Objects, which he calls “the distributed singleton with a SQLite database.” Each Durable Object, per the post, is like a small, individually addressable server with its own relational database, single-threaded JavaScript execution, WebSocket handling and a local SQLite database that can be accessed synchronously.
Dahl gives a chat example: one Durable Object per channel shards both data and WebSocket connections, which he says makes the application scalable. He adds that Queues, KV, Durable Execution (Cloudflare’s Workflow API) and even Git storage can be built on top of the same abstraction.
What celld was meant to fix
The gap, according to the post, is running that model outside Cloudflare. Workerd is already open source, but its Durable Objects support is limited to a single instance. Dahl says he wanted the distributed version, with the platform handling placement, routing and durable storage, and that is why he started celld.
He describes celld as “one binary, written in Rust, with object storage as its only external service dependency” — a deliberate contrast with what he learned operating Deno Deploy, which he characterizes as multiple public clouds, multiple databases and deeply entangled services.
Cloudflare’s post does not state terms, pricing or a timeline for the merge, and the text available ends mid-sentence while Dahl is describing what running the model involves. For details on the Deno runtime itself, the post directs readers to Dahl’s separate announcement on the Deno blog.
Related reading
Sources
- Deno is joining Cloudflare — Cloudflare Blog
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