Run AI coding CLIs and frameworks in the browser

BrowserCode is a browser-based playground for fast-prototyping full-stack apps and sharing them instantly. It runs on BrowserPod, a multi-language WebAssembly sandbox (Node.js, Rust, and Python in preview), with no installs, no servers, and no cloud compute.

Table of contents

• What is BrowserCode?
• Quickstart
• Make it your own
• Embedding
• Breaking BrowserCode
• Roadmap

What is BrowserCode?

BrowserCode is a browser-based coding sandbox. It's a working example of BrowserPod, and includes:

• Node.js v22, Rust and Python (preview) running in the browser via WebAssembly (more runtimes coming)
• A browser-contained, POSIX-like filesystem
• Command line tools: bash, git, npm, pnpm, curl, ripgrep and fd
• Browser sandbox isolation from the user's operating system
• Restricted outbound networking: HTTPS only, to an allowlist that includes the npm registry, Yarn 2+, GitHub (github.com and raw.githubusercontent.com) and the major AI provider APIs
• Instant previews over URL via BrowserPod's portal function
• Support for Express.js, Svelte, Next, Nuxt and React (with Wasm overrides)

BrowserCode started out as a way to run AI coding CLIs entirely client-side. It's since grown into a full IDE: alongside the CLIs, it can boot and preview web frameworks directly in the browser, so you can prototype an agent's output without ever leaving the tab.

BrowserCode 1.3.0 is our latest beta release. It runs a full code editor, development environment, and unmodified versions of Claude Code, Codex CLI and Pi, completely client-side.

Quickstart

Want to try BrowserCode without installing anything? Use the hosted app.

1. Go to browsercode.io
2. BrowserCode will boot instantly, opening with a quick modal tutorial to guide you
3. Pick an agent from the sidebar, or open the IDE playground to boot a framework template
4. Claude Code signs in by copying a code from a separate tab; Codex CLI asks for an OpenAI API key, stored in your browser; Pi signs in to the provider of your choice with its own /login

Make it your own

Want to run your own copy, customize the CLIs, or contribute? Clone the repo and run it locally.

1. Clone the repository and install dependencies

   git clone https://github.com/leaningtech/browsercode.git
   cd browsercode
   npm install

2. Get a BrowserPod API key at browserpod.io and expose it to the app as VITE_API_KEY

   echo "VITE_API_KEY=your-key-here" > .env

3. Start the dev server

   npm run dev

4. Open the printed local URL in a Chromium-based browser

Other useful scripts:

• npm run build — build a production bundle
• npm run preview — preview the production build locally
• npm run check — type-check the project
• npm run lint / npm run format — lint and format with Prettier + ESLint

CLI availability and behavior are configured in src/lib/config/tools.ts — this is the place to start if you want to add or tweak a CLI.

Embedding

BrowserCode can run inside another site's page through /embed, composed entirely from the query string.

<iframe
	src="https://browsercode.io/embed?framework=vite&view=preview"
	allow="cross-origin-isolated"
	style="width: 100%; height: 600px; border: 0"
></iframe>

BrowserPod needs SharedArrayBuffer, so the embedding page must send Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp, and the iframe must carry allow="cross-origin-isolated".

Parameters, panes and further detail are in docs/embedding.md.

Breaking BrowserCode

This is BrowserCode beta. Don't be kind to it. Stretch it, bend it, find out what breaks. Here are a few walls you might hit:

• At launch, each agent is given an instructions file (CLAUDE.md for Claude Code, AGENTS.md for Codex CLI and Pi) so it understands it is running in a custom environment. However, it may first attempt its default behavior before referencing the file
• Pi is installed from npm on its first launch. For Anthropic, pick Copy code login in /login: the default browser login redirects to a localhost callback that can't reach the pod
• BrowserCode doesn't yet support native binaries. For more information, see the BrowserPod documentation
• Outbound connections are HTTPS-only (port 443) and limited to the allowlist: plain HTTP, SSH (so git@github.com remotes) and other ports are refused, and so is localhost from inside a pod. Portals still expose servers you start in a pod
• For maximum compatibility, please use a Chromium browser. Safari currently isn't supported

Roadmap

	CLI	Status
	Claude Code	✅ Beta open now
	Codex CLI	✅ Beta open now
	Pi	✅ Beta open now
	Antigravity	🚧 Coming soon
	OpenCode	🚧 Coming soon

Cloning GitHub repos directly into your BrowserCode workspace is available in beta from the IDE landing page.

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