# Limitations

agentOS is a Linux environment with a POSIX-compliant virtual kernel. It handles most agent workloads (coding, scripting, file I/O, networking) with near-zero overhead.

## Sandbox mounting

When a workload needs a full Linux OS, agents can escalate to a full sandbox on demand without changing code. The [external sandbox](/agentos/docs/sandboxes) extension mounts the sandbox as a filesystem and lets you execute commands on it, like mounting a hard drive on your own machine. Files written in the VM are available in the sandbox and vice versa.

See [agentOS vs Sandbox](/agentos/docs/versus-sandbox) for a detailed comparison.

## Limitations

### Software registry

agentOS uses its own [software registry](/registry) of popular tools cross-compiled for the runtime. You cannot download and install arbitrary binaries (for example via `curl` or `apt`), and standard Linux package managers (`apt`, `yum`) are not available since agentOS runs a streamlined Linux environment rather than a full distribution. Native binaries that are not yet available in the registry (such as Go, Rust, or C++ toolchains) require a full [external sandbox](/agentos/docs/sandboxes).

See [Software](/agentos/docs/software) for how to install and configure available packages.

### Lightweight Linux kernel

agentOS provides a POSIX-compliant virtual Linux kernel with full filesystem operations, networking, and process management. It implements a focused subset of the kernel surface, so a few Linux-specific features are not available:

- Kernel modules and eBPF
- Container runtimes (e.g. Docker)
- File watching (`inotify`, `fs.watch`)

### No hardware access

The VM has no access to GPUs, USB devices, or other hardware.