Cloudflare Agents Week in Plain English

Cloudflare ran "Agents Week" last week and it was quite impressive, both in the number of announcements and the depth of what they shipped. Great job @eastdakota ,@Cloudflare, @ritakozlov, @minglu! As someone who's tinkered with Cloudflare for some personal projects, I was excited to see them make such huge strides toward rebuilding their developer platform to be written and run by AI. Yesterday I sat down to play around with the announcements and see what impact they actually make. As part of that I built a prototype I called Keystone: a property management system that stitched six of the new features together end-to-end, including voice agent, browser automation, multi-agent coordination, durable workflows, persistent storage, and inbound email. If Cloudflare said building on top of this would be simple and lightweight, I wanted to see whether that was actually true. The TLDR for those who don't care about the details: I really like the direction Cloudflare is going, and I plan to build more on top of it after these releases. For everyone else, here is a breakdown of what I learned in my best attempt at plain English. The stuff that actually matters 1. Dynamic Workers — "give the AI a safe place to run its own code" How it used to be: When an AI agent writes code (and increasingly they do, not just tool calls but actual code), that code has to run somewhere. The safe option was spinning up a container: basically a little virtual computer, locked off from everything else. Secure, but slow to start and expensive to leave running. The fast option was just... running the AI's code directly inside your own app. Faster, yes, but also the software equivalent of letting a stranger borrow your house keys. One bad line of code and your whole app is compromised. So developers picked: pay a lot and wait, or move fast and take on real risk. What changed: Dynamic Workers give you a third option: a tiny, walled-off environment that starts up in milliseconds. Think of it less like spinning up a virtual computer and more like a sealed glass box. The AI drops its code inside, the code runs, the box gets thrown away. Cheap enough to do a thousand times a minute, safe enough that the code can't escape the box. Why it matters: This is what makes "agents that write code" work at any real scale. Any time an AI agent needs to actually run code it wrote (not just describe it, but execute it), someone has to solve this problem. Every provider building coding agents is wrestling with it in their own way. Dynamic Workers is Cloudflare's answer, and it's a good one: fast enough to run constantly, cheap enough to not burn money on idle time, safe enough that you don't need to worry about the AI doing something bad with your app. My take: This is the single most important announcement of the week, even though it's the least exciting to look at. It's the foundation that makes everything else in Agents Week actually affordable to run. 2. Sandboxes (GA) — "give the agent a real computer" How it used to be: If your agent needed a full computer to work with (not just to run a quick snippet of code, but to install software, download files, and juggle multiple tasks), you were renting a virtual machine or wrestling with Docker. And if the agent paused, everything reset by default. You were re-setting up the same workspace every time. What changed: Sandboxes are now generally available. Each one is a real computer your agent can use. It can install whatever it needs, work on a task across multiple steps, and pick up exactly where it left off between turns. Think of it as a laptop your agent borrows, except it never has to shut down and you don't have to ship it anywhere. Why it matters: There's a real distinction between "run this snippet" (Dynamic Workers) and "do development work that takes hours and spans multiple steps" (Sandboxes). Coding agents need both. Before, you had to build both yourself. Now Cloudflare gives you both, with one bill and one dashboard. My take: Sandboxes have been in beta since mid-2025, so this isn't brand-new. Hitting GA is the signal that you can build real things on it in production. If you wanted that before, you were reaching for a third-party service like E2B or Modal. Now there's a first-party option on Cloudflare. One fewer vendor to bring in. 3. The Agents SDK — "Project Think" and Fibers How it used to be: Let's say you're building an agent that has to do a five-step workflow: acknowledge the request, find a contractor, dispatch them, notify the landlord, confirm with the tenant. If your server crashes halfway through step three, what happens? In the old world, you pulled in a workflow engine (Temporal, Airflow, AWS Step Functions), wrote a bunch of glue, and hoped for the best. Or you used a queue and prayed. What changed: Cloudflare added something called Fibers, a way for the agent to pause mid-task, save its place, and pick up later. Each step gets saved automatically. If the server dies at step