---
description: Learn how the Sandbox SDK works, including architecture, lifecycle, security, and sessions.
title: Concepts
image: https://developers.cloudflare.com/og-docs.png
---

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> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/sandbox/llms.txt  
> Use this file to discover all available pages before exploring further.

# Concepts

Last updated Aug 25, 2026|Copy as Markdown|[View as Markdown](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/index.md)|[Agent setup](https://4f1c5cd2.previews.developers.cloudflare.com/agent-setup/)

These pages explain how the Sandbox SDK works, why it's designed the way it is, and the concepts you need to understand to use it effectively.

* [Architecture](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/architecture/) \- How the SDK is structured and why
* [Sandbox lifecycle](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/sandboxes/) \- Understanding sandbox states and behavior
* [Container runtime](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/containers/) \- How code executes in isolated containers
* [Session management](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/sessions/) \- When and how to use sessions
* [Preview URLs](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/preview-urls/) \- How to expose sandboxed services on the public internet.
* [Security model](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/security/) \- Isolation, validation, and safety mechanisms
* [Terminal connections](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/concepts/terminal/) \- How browser terminal connections work

## Related resources

* [Tutorials](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/tutorials/) \- Learn by building complete applications
* [How-to guides](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/guides/) \- Solve specific problems
* [API reference](https://4f1c5cd2.previews.developers.cloudflare.com/sandbox/api/) \- Technical details and method signatures

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