Cloudflare Acquires Deno: Ryan Dahl's Team Merges workerd and celld for Self-Hosted Workers
Ryan Dahl, who created Node.js in 2009 and spent the subsequent decade building Deno as its successor, is joining Cloudflare along with the entire Deno team. The move consolidates two of the most important open-source JavaScript runtime projects under one roof, with a specific target: self-hosted Workers infrastructure.
The deal merges workerd — Cloudflare’s open-source implementation of the Workers runtime — with celld, Dahl’s Rust-written distributed compute project. Together, they form the foundation for running Cloudflare Workers and Durable Objects on any infrastructure, not just Cloudflare’s network.
What celld is and why it matters
Dahl’s path from Node.js to Deno to celld tracks a consistent search for simpler abstractions. Node.js solved async I/O. Deno improved the JavaScript developer experience. celld attacks a harder problem: distributing computation and state across machines without requiring each application to assemble its own infrastructure stack.
The key abstraction is Durable Objects. A Durable Object is a distributed singleton — individually addressable, with its own SQLite database, handling WebSockets natively. Each instance is single-threaded (easier to reason about) but the objects collectively can span machines, sharding data and connections automatically. A chat application built on DOs gives you per-channel state management without hand-rolling distributed coordination.
The problem Dahl identified: while Cloudflare’s network can run this model at scale, running it outside Cloudflare required assembling multiple clouds, multiple databases, and deeply entangled services. workerd is open source but its Durable Objects support was limited to a single instance — the distributed version required celld.
celld’s design constraint was deliberate: one Rust binary, one external dependency (object storage). Compute, relational databases, queues, and real-time communication primitives all built into the runtime. You manage many instances of celld and a single object storage bucket. Nothing else.
Why this matters for AI agents
Cloudflare Workers has become the default runtime for AI agent workloads deployed at the edge. Workers AI handles embedding and inference. Workers KV stores agent state. Durable Objects manage long-running agent sessions and multi-step tool-call sequences. The entire orchestration layer for agent frameworks like AI Gateway, OpenRouter edge routing, and agent coordination tools runs on this primitive.
The combination of workerd and celld means these primitives can now run inside enterprise data centers, private clouds, and air-gapped environments — without requiring traffic to route through Cloudflare’s network. An AI agent infrastructure that today depends on Cloudflare’s global edge can be replicated on-prem with the same code.
For labs and enterprises building production agent systems, self-hosted Durable Objects removes a significant constraint on where agents can run and what data they can access.
What happens to Deno
Dahl’s announcement draws a clear line under standalone Deno development. The runtime is not being paused — it is being sunseted. Cloudflare and Dahl confirmed that active development of the Deno runtime ends with the acquisition; the codebase remains open source and will receive security updates and bug fixes for approximately one year, but new feature work shifts entirely to the combined workerd/celld project.
Deno Deploy, the managed serverless hosting product, is being shut down within six months. Existing paid customers are being migrated to Cloudflare Workers.
Kenton Varda, who designed Durable Objects at Cloudflare, co-authored the acquisition announcement with Dahl. Merging celld into workerd is described as a new engineering effort to begin post-acquisition — celld was developed independently by Deno as a standalone Rust daemon, and the technical integration work is starting now.
Acquisition terms were not disclosed.