# Flax Cloud Documentation

> Flax Cloud gives developers instant, isolated cloud sandboxes you drive from an API, SDKs, or a CLI: run code, agents, builds, and live app previews in a disposable, hardened container.

## Getting Started

- [Introduction](https://flaxcloud.com/docs/index.md): Flax Cloud gives you instant, isolated cloud sandboxes you can drive from an API, SDKs, or a CLI. Run code, agents, builds, and live app previews in a disposable container.
- [First sandbox in 5 minutes](https://flaxcloud.com/docs/quickstart.md): Create your first Flax Cloud sandbox, run code, move files, open a preview, connect a browser over CDP, snapshot it, and clean up.

## Core concepts

- [Core concepts](https://flaxcloud.com/docs/concepts.md): Sandboxes, templates, lifecycle and states, networking, persistence, snapshots, forks, browser sandboxes, and the isolation model.

## Guides

- [Running commands](https://flaxcloud.com/docs/commands.md): Run shell commands in a sandbox, synchronously or asynchronously, poll for long-running output, and use the interactive terminal.
- [Files](https://flaxcloud.com/docs/files.md): Upload, download, list, and delete files inside a sandbox filesystem over the API.
- [Previews](https://flaxcloud.com/docs/previews.md): Run a web server inside a sandbox and reach it from your browser, via a private owner-only proxy or a shareable secret link with automatic TLS.
- [Browser automation](https://flaxcloud.com/docs/browser.md): Drive a real Chromium browser inside a sandbox over the Chrome DevTools Protocol. Connect Playwright, Puppeteer, browser-use, or Stagehand, or use the built-in screenshot and action helpers.
- [Custom images](https://flaxcloud.com/docs/images.md): Bring your own dependencies by registering a custom image as a template, from any public registry image, a Dockerfile, or the declarative FlaxImage builder.
- [Snapshots](https://flaxcloud.com/docs/snapshots.md): Capture a sandbox's filesystem and configuration as a named, reusable artifact, then spin up fresh sandboxes from it. Ideal for prepared agent and test environments.
- [Forks](https://flaxcloud.com/docs/forks.md): Branch a running or stopped sandbox into a new, independent copy. Perfect for exploring multiple agent paths or eval branches from one base state.

## SDKs & CLI

- [Python SDK & CLI](https://flaxcloud.com/docs/sdk.md): The official flaxcloud Python client and flax command-line tool: install, authenticate, run commands, manage files, sessions, snapshots, forks, custom images, and the browser.
- [JavaScript / TypeScript SDK](https://flaxcloud.com/docs/sdk-js.md): The official @flaxcloud/sdk client for Node, edge runtimes, and the browser. Zero runtime dependencies, full TypeScript types, ESM + CommonJS.

## API

- [API reference](https://flaxcloud.com/docs/api.md): The Flax Cloud REST API: base URL, authentication, response conventions, error shape, and the full interactive endpoint reference.

## Platform

- [Plans & limits](https://flaxcloud.com/docs/plans-and-limits.md): Plan quotas, what counts as usage, workspace retention, rate limiting, and the limit error codes.
- [Security](https://flaxcloud.com/docs/security.md): How sandboxes are isolated, how to handle credentials, sharing previews safely, abuse prevention, and reporting a vulnerability.
- [Launch readiness and security caveats](https://flaxcloud.com/docs/launch-readiness.md): What Flax Cloud currently enforces, what is still a launch caveat, and what should be fixed before broader public or enterprise use.
- [Troubleshooting](https://flaxcloud.com/docs/troubleshooting.md): Common Flax Cloud errors and how to fix API keys, quota failures, capacity responses, previews, browser CDP URLs, files, and cleanup.

## Resources

- [Changelog](https://flaxcloud.com/docs/changelog.md): Notable user-facing changes to the Flax Cloud platform, API, SDKs, and CLI.

## Playbooks

- [Coding agents](https://flaxcloud.com/docs/coding-agents.md): Run coding agents like Claude Code and Codex in isolated Flax Cloud sandboxes with full terminal, filesystem, and git access. Clone a repo, let the agent work, and pull back the diff.