Deno is joining Cloudflare

For years, we’ve been working to make building server software simpler. We questioned how modules could be distributed, what security guarantees a JavaScript runtime could provide, what belonged in a complete toolchain, and how easily an application could be distributed as a standalone executable. Compatibility with Node.js became an important part of that work too: our users wanted the Deno improvements while continuing to plug into the existing JS ecosystem. The team and community built a runtime that brought these capabilities together and challenged assumptions about what JS development could look like.

Today we’re announcing that the entire Deno team is joining Cloudflare to take that work further.

Our ambition has always extended beyond the runtime. I wrote about this in my JavaScript Containers blog post: compute, storage, and communication working together, without every application assembling its own infrastructure.

With Deno Deploy, we took another step towards that goal. We wanted to make running applications as straightforward as possible. But building and operating Deploy also showed us how much complexity remained underneath that developer experience. I wanted to simplify that layer, too.

This led to celld. Building on the Cloudflare Workers programming model, celld lets developers build distributed applications from the start while making the system simple to operate. What excites me greatly is that the scaling is built into the programming model, rather than infrastructure each app has to assemble itself.

The progression from Deno to Deno Deploy to celld explains why this move makes sense to us. At Cloudflare we’ll combine our work with that of the Workers and Durable Objects teams. We want to make this programming model the default way to build servers, whether you run on Cloudflare’s network or your own infrastructure.

Joining also means choosing where to focus our effort. We’ve decided to put our future development work into this shared platform rather than continuing to develop a separate runtime and hosting service. We know this is a consequential change for people who have built on Deno.

To everyone who contributed code, built businesses on Deno, reported problems, and trusted our direction: thank you. Here’s what this means concretely:

• We will support the Deno runtime for another year with monthly releases containing bug fixes and security updates. After that year we will end our development of the Deno runtime. Deno will remain open source, and we welcome others who want to continue its development.
• Deno Deploy will continue operating for six months before shutting down. We will provide migration support for paying customers moving to Cloudflare Workers.
• JSR will continue operating, with its infrastructure moving to Cloudflare.
• We will continue supporting rusty_v8 and work toward integrating it into workerd.

The need for better abstractions is especially acute with AI. Durable Objects bring together capabilities that are particularly useful for agent harnesses: inexpensive, serverless execution, persistent state, WebSockets, and a high-level JavaScript interface. This is what I’m most excited to explore and why celld focuses on Durable Objects.

Kenton Varda and I explain more in our joint post on the Cloudflare blog. If you’re building agents at scale and want to run them on your own infrastructure, please reach me now at ry@cloudflare.com.