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On 2026-08-05 Kenton Varda demoed an agent-built 1-shot multiplayer Paint-style…

Brief

Cloudflare OS is a new agent-first personal app platform released by the Cloudflare team and announced around 2026-08-05; it’s a Sandstorm.io remake rebuilt on Cloudflare Workers and positioned as the culmination of Kenton Varda’s decade-long plan. @bjyule recounts a demo where an agent generated a multiplayer Paint-like app in one shot, Kenton drew a Tic‑tac‑toe board and an X, and the agent immediately drew a circle — illustrating their claim that agents can use software as easily as humans. The platform adopts Sandstorm’s Gadget/Grain sandboxing: each document or app instance runs isolated, so the platform controls access (preventing cross‑Gadget leaks) and every user has their own modifiable copy of the code. That isolation is presented as the enabler for agents to safely edit user app instances, letting non-technical users 'vibe code' without the security risks of standard SaaS.

Why it matters

On 2026-08-05 Kenton Varda demoed an agent-built 1-shot multiplayer Paint-style app (shared by @bjyule): Kenton drew a Tic‑tac‑toe board and an X, and the agent responded by placing a circle in the upper-left — the team called this an 'accidental' moment showing agents can interact with software as easily as humans.

Key details

  • Cloudflare OS is being released as of the announcement: a remake of Sandstorm.io built on Cloudflare Workers that deeply leverages AI; Kenton frames it as the culmination of his 10-year plan and published the project at github.com/cloudflare/cloudflare-os.
  • Cloudflare OS reuses Sandstorm’s security model: a 'Gadget' equals a Sandstorm 'Grain' — each document or app instance runs in its own sandbox, which prevents a Gadget from leaking itself and lets the platform centrally manage access control.
  • Because every user runs their own isolated copy of code, the platform allows agents to modify a user's copy on demand — enabling non-technical users to request new features safely and avoiding limitations of central SaaS where users don't run their own instances.
Source evidence

One of my favorite moments over the past 6 months when building the core tech (ie the kernel) behind Cloudflare OS was when Kenton came to me and said "I need to show you something."

He then began to demo a 1-shot where he asked the agent to build him a simple multi-player Paint stye app. Something we had done dozens and dozens of times before.

After a minute of spinning, a simple multi-player canvas appeared on the screen exactly like you'd expect. Kenton drew two vertical and two horizontal lines using the pen tool creating a Tic-tac-toe board. He then drew an 'X' right in the middle.

Finally - navigating back to the 'agent' who built the app. He said "your turn."

A few seconds later a circle appeared in the upper left corner of the board he had just drawn by hand.

"Oh my god - we just accidentally invented software that agents can use as easily as humans."

Kenton Varda (@KentonVarda)

Today we are releasing Cloudflare OS, a chatbot with connectors, just like every other tech company is doing.

Except actually, it's different. This is a remake of Sandstorm[.]io, my startup from 10 years ago, except this time built on Cloudflare Workers (the platform I've spent the last 9 years building) and deeply leveraging AI. This is more or less the culmination of my secret 10-year master plan.

This is a full-on personal app vibe coding platform, in which the sandbox is so secure that you can pretty much go wild -- the AI cannot introduce a significant security bug. We believe a company's security team can feel comfortable giving non-technical users permission to vibe code and then sleep soundly at night.

How is that possible? It's the Sandstorm security model, revisited. A "Gadget" is the same thing as a Sandstorm "Grain": a fine-grained app instance. For example, if you have a document editor app, each document runs as a separate instance of the app, in a separate sandbox (one "Gadget").

This means two things, both of which I think are Big Deals:
1. The platform can manage all access control, by controlling who can access the Gadget at all. There is no way the Gadget can accidentally leak itself to an attacker -- even an attacker who has access to other Gadgets based on the same app.
2. Since everyone is running their own copy of the code, everyone can freely modify their copy of the code.

Think about #2 a bit more.

What if, when you wanted a new feature in the software you are using, you could just prompt your agent to add it?

This doesn't work in the cloud Software-as-a-Service model, because you are not running your own copy of the app.

Sandstorm tried to change that 10 years ago, but the world wasn't ready, because not enough people had the skills or patience to actually modify their software. AI has changed that. Now you just ask the agent -- the same agent that you are using to help you interact with the Gadget can also modify the code of the Gadget.

And it is so fun.

github.com/cloudflare/cloudf…

Link

GitHub - cloudflare/cloudflare-os: Agent workspace built on Cloudflare Workers for creating...

Agent workspace built on Cloudflare Workers for creating documents, building apps, and running agents with your company’s context and systems. - cloudflare/cloudflare-os
github.com

— https://nitter.net/KentonVarda/status/2084990137180590572#m