---
title: Cosmonic Desktop Beta — A sandbox for your agent's code
description: Cosmonic Desktop runs AI-generated apps in a capability-driven WebAssembly sandbox on your machine. Free public beta for macOS, Windows, and Linux — sign up and we'll email your install link.
image: https://learn.cosmonic.com/hubfs/cosmonic-desktop-beta/inspect-first-flight.png
---

[cosmonic desktop](https://cosmonic.com)

[docs](https://cosmonic.com/docs/desktop/) [cosmonic.com](https://cosmonic.com)

Public Beta · Free · macOS, Windows & Linux

# A sandbox for your agent's code.

Your agent wrote the code, but can you trust it?

## Join the beta

We'll email your personal install link.

We'll only email you about Cosmonic Desktop.

Sound on

**Cosmonic Desktop** runs AI-generated apps in a capability-driven WebAssembly sandbox on your machine: no file or network access and no keys unless you explicitly allow it. No account, no cloud, and no Kubernetes required.

Builder + your coding agent

## Prompt to a sandboxed app, instantly

Cosmonic Desktop includes an integrated MCP server that gives your coding agent the skills to compile your apps and deploy them **into your local sandbox**. Open the Builder, describe the app you want, and hand it to Claude Code, Codex, or the agent you already use.

![Describe an app, hand it to your coding agent, and watch it build and deploy to Running in Cosmonic Desktop.](https://learn.cosmonic.com/hubfs/cosmonic-desktop-beta/build-to-running.gif)

Describe an app, hand it to your agent, and watch it reach *Running*.

Capability-driven security

## Move quickly with guardrails you can trust

Containers and seccomp run on **ambient authority**: a program inherits the permissions of whatever launched it. Cosmonic Desktop compiles your code to a **WebAssembly component** that begins with **no authority at all**: no filesystem or network access, not even a clock, until the host grants that capability.

![The Inspect view lays out exactly what a component can touch: four kinds of imported access, each an explicit grant from the host, feeding a single web endpoint.](https://learn.cosmonic.com/hubfs/cosmonic-desktop-beta/inspect-first-flight.png)

Inspect the capabilities that your components want to use.

Open standards, no lock-in

## From prompt to production

Components ship as standard **OCI artifacts** and deploy through Kubernetes-style declarative manifests, the same manifest locally and in production.

The runtime inside Desktop is CNCF Incubating [wasmCloud](https://wasmcloud.com), so the boundary you trusted in development is the boundary that ships, on your infrastructure, with no proprietary platform in the loop.

## Free. Local. Cleared for launch.

[Join the beta](https://learn.cosmonic.com/cosmonic-desktop-beta#signup)

© 2026 Cosmonic · [Desktop docs](https://cosmonic.com/docs/desktop/) · [wasmCloud](https://wasmcloud.com)