Browser sandboxes

On freegent.ai all code the agent writes runs inside your browser, never on a server. JavaScript, Python and the WASM shell run in a hidden <iframe sandbox="allow-scripts"> with an opaque origin. Code there cannot read your API keys, chats, the page's DOM or the dev-server token. It sees project files only through a small set of file operations that the page carries out for it.

What each language can do

• JavaScript runs in a Worker inside the frame, so a tight loop cannot freeze the page. There is no DOM or canvas and no npm packages (use bash with npm and node for those). For anything visual the agent writes a self-contained HTML file and checks it with check_page.
• Python runs in Pyodide. Pure-Python packages install with micropip; packages with C extensions work only if Pyodide ships a build of them, as it does for NumPy, pandas, Matplotlib and many others.
• Bash runs in a bash-compatible shell written in TypeScript that runs in the browser. It implements 248 of the most common bash commands, builtins and keywords: grep, sed, awk, find, sort, tr and similar. About 40 of them (such as jq, bc, lua, sqlite and ruby) are WebAssembly packages that download on first use. It can install npm and pip packages into the project (npm install, pip install) and run them with node and python3. There is no system package manager such as apt, and nothing outside the project to install into.

Network

fetch(), curl and wget reach sites that allow cross-origin requests directly, and other sites as a plain GET through FreeGent's proxy. Python requests and urllib do not work in Pyodide; the agent uses the fetch_url tool instead.