> ## Documentation Index
> Fetch the complete documentation index at: https://docs.celesto.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Why Celesto

> Learn why Celesto gives AI agents secure sandboxed computers with durable state, petabyte-scale workspace storage, browser access, ports, and open-source runtimes.

AI agents need more than function calls. They need a computer where they can inspect files, run commands, browse the web, install tools, start apps, save progress, and recover when a task takes longer than one turn.

Celesto gives agents that computer without putting your own infrastructure at risk. Each agent runs inside an isolated sandbox with a shell, files, networking controls, optional browser access, durable state, and workspace storage that can handle much larger projects than the VM root disk.

## What makes it different

<CardGroup cols={2}>
  <Card icon="shield-halved" title="Isolation by default" href="/smolvm/concepts/security">
    Run untrusted code, generated scripts, build commands, and browser automation away from your app server.
  </Card>

  <Card icon="database" title="Large durable workspaces" href="/celesto-sdk/features/petabyte-storage">
    Keep repositories, datasets, build output, and generated files in a petabyte-scale CelestoFS workspace.
  </Card>

  <Card icon="rotate" title="State that survives" href="/celesto-sdk/features/persistence">
    Stop a computer and start it later with saved root disk and workspace state.
  </Card>

  <Card icon="github" title="Open-source foundations" href="/getting-started/hosted-and-open-source">
    Use the hosted platform, or build locally with SmolVM, SmolFS, and Agentor.
  </Card>
</CardGroup>

## When Celesto fits

Use Celesto when your agent needs to do real computer work:

* clone a repository and run tests,
* install dependencies and build a project,
* browse a site or inspect a web app,
* generate files or artifacts,
* expose a preview app or API,
* pause and resume the same task later.

If your agent only needs a single stateless API call, Celesto may be more than you need. If your agent needs a workspace, a terminal, a browser, or durable files, Celesto is the right primitive.

## Start building

<CardGroup cols={3}>
  <Card icon="rocket" title="Quickstart" href="/celesto-sdk/quickstart">
    Create your first hosted Celesto computer.
  </Card>

  <Card icon="computer" title="Agent computers" href="/getting-started/agent-computers">
    Understand the core sandbox primitive.
  </Card>

  <Card icon="code" title="Coding agents" href="/getting-started/coding-agents">
    See how coding workflows fit together.
  </Card>
</CardGroup>