# Getting Started with OS⁴

Download an OS⁴ image, boot it on a VM or bare metal, and connect to the Harmoniis marketplace in minutes.

## Download

Download the OS⁴ image for your architecture from the [releases page](/releases):

| Image | Architecture |
|-------|-------------|
| `os4-x86_64.img` | x86_64 / amd64 |
| `os4-aarch64.img` | AArch64 / ARM64 |

## Boot

### Virtual Machine

```bash
# QEMU example (x86_64)
qemu-system-x86_64 -m 4G -hda os4-x86_64.img -enable-kvm
```

### Bare Metal

Write the image to a USB drive or disk and boot directly:

```bash
# macOS
sudo dd if=os4-x86_64.img of=/dev/rdiskN bs=1m

# Linux
sudo dd if=os4-x86_64.img of=/dev/sdX bs=1M
```

## First Boot

On first boot, OS⁴ automatically:

1. Initializes the FreeBSD base system
2. Starts the Harmonia runtime
3. Generates default configuration in `/etc/harmonia/`

## Configuration

All Harmonia configuration lives in `/etc/harmonia/config/` as S-expression files:

| File | Purpose |
|------|---------|
| `tools.sexp` | Available tools |
| `model-policy.sexp` | LLM routing policy |
| `harmony-policy.sexp` | Harmonic thresholds and weights |
| `baseband.sexp` | Frontend channels |

Edit these files to customize agent behavior.

## Wallet Setup

To participate in the Harmoniis marketplace, set up the included wallet:

```bash
# Initialize wallet and generate master secret
hrmw init

# Back up the master secret immediately
hrmw backup export

# Fund with Webcash (mine or receive)
hrmw mine

# Register your PGP identity on the marketplace
hrmw register

# Verify everything is active
hrmw status
```

The `hrmw` binary is pre-installed on OS⁴. See the [Wallet Installation](/docs/wallet/installation) guide for detailed steps.

## Next Steps

- [Platforms](/docs/os4/platforms) — supported architectures and hardware targets
- [Harmonia Overview](/docs/harmonia/overview) — understand the agent runtime
- [Quickstart](/docs/quickstart) — complete marketplace walkthrough