Requirements

This page lists what you need before installing Arclight: the host, the folders, the network ports and the browser. Read it first if you are choosing between Docker, a NAS and a Windows PC. It only states what the project ships or enforces. Arclight does not publish a CPU or RAM minimum, and this page does not make one up.

What you need at a glance

You need	Why
A machine that stays on (NAS, home server, mini PC)	Arclight searches, downloads and imports in the background, on a schedule.
Docker with Compose v2 (`docker compose`), or Node 24 and pnpm 10 for a native Windows install	Docker is the main way to run it. See install-other-platforms.md to choose a guide.
A TMDB API key (free)	Arclight reads all series and movie information from TMDB. See first-run-wizard.md.
One way to download	The built-in torrent engine, which is included and already set up. External clients such as qBittorrent are optional.
Optional: a Proton VPN account	Only for the VPN layouts. The bundled Docker files are written for Proton over WireGuard with Gluetun; other providers are covered in install-docker.md.
Optional: indexers	Arclight ships site definitions; you still add the indexers you have access to.

Hardware

The project does not state minimum CPU, RAM or disk figures, and none are enforced in code. What can be said from the Dockerfile, the README and the release notes:

The image is small: about 80 MB to pull and about 220 MB unpacked, and it answers HTTP within a couple of seconds of starting.
Release images are built for linux/amd64 and linux/arm64 (see RELEASING.md).
Arclight keeps one SQLite database and its logs in the config folder (arclight.db, logs/, plus backups/, definitions/ and torrents/ as you use them). Put the config folder on storage that survives reboots.
Transcode rules can encode on a GPU: Intel (Quick Sync, VA-API), AMD (VA-API) or NVIDIA (NVENC). The arm64 image has no Quick Sync or VA-API. Many NAS CPUs have no integrated GPU, and on those transcoding runs on the CPU. See hardware-transcoding.md.
Each extra container costs memory. FlareSolverr runs a headless browser, and the optional Whisper container runs a speech model on the CPU by default, so those are the heavy ones. If a small machine struggles, drop the optional extras first.
Disk space is mostly your media. A download stays in the downloads folder until it is imported, and longer if you seed.

Operating systems

Platform	Guide
Linux with Docker	install-docker.md, the reference guide
Synology, UGREEN, Unraid, TrueNAS SCALE, QNAP	install-synology.md, install-ugreen-nas.md, install-unraid.md, install-truenas-scale.md, install-qnap.md
Windows (Docker, or native without Docker)	install-windows.md
macOS, Raspberry Pi	install-macos.md, install-raspberry-pi.md
Portainer users	install-portainer.md

The full list is in install-other-platforms.md.

For the VPN layouts the host must provide /dev/net/tun and let the Gluetun container use the NET_ADMIN capability. If Gluetun fails to start, see Troubleshooting: container restarting.

Folders and permissions

Arclight needs two places on disk. In Docker they are mounted into the containers:

Host folder (your `.env` variable)	Inside the container	Holds
`CONFIG_ROOT` (a parent folder; Arclight uses `<CONFIG_ROOT>/arclight`)	`/config`	The database, logs, backups, torrent resume data
`DATA_ROOT` (one share)	`/data`	`downloads/`, `media/tv/` and `media/movies/`

Arclight mounts DATA_ROOT at /data (so does qBittorrent, if you add it), and your root folders in Arclight are /data/media/tv and /data/media/movies. One mount matters: Linux cannot hard-link between two different mounts, even on one disk, so separate mounts for downloads and library make every import a slow full copy that needs double the space. One mount gives instant hard links and seeding keeps working. See install-docker.md and folders-and-hardlinks.md.

The containers run as the numeric user and group you give them (PUID and PGID), so that user must be able to read and write both folders.

Network ports

Port	Used by	Published?	Notes
7878/tcp	Arclight web UI and API	Yes, in every layout	Change the host side of the mapping (`"7979:7878"`) if another app already uses 7878.
8080/tcp	qBittorrent web UI	Only if you start the optional `qbittorrent` profile	Not used by the built-in engine. In VPN layouts the port line on `gluetun` is commented out until you need it.
6881/tcp and udp	Torrent peer port	Only for qBittorrent in the no-VPN layout (or if you publish the built-in engine’s port yourself)	In the VPN layouts no peer port is published: Proton forwards a port at runtime and Arclight moves the built-in engine’s listener (and qBittorrent’s, if used) onto it.
8000/tcp	Gluetun control server	No (internal)	Arclight reads VPN status at `http://localhost:8000`.
8191/tcp	FlareSolverr	No (internal)	Solves Cloudflare challenges for indexers.
9000/tcp	Whisper (optional)	No (internal)	Only with the `whisper` profile.

In the VPN layouts every published port is published on the gluetun container, because Arclight (and qBittorrent, if used) shares its network. You still open the UI at http://<your-host>:7878.

Arclight does not serve HTTPS itself. If you expose it beyond your home, put it behind a TLS reverse proxy and keep sign-in on (see users-and-security.md).

Accounts and keys

Item	Needed for	Where it comes from
TMDB v3 API key	Required: series and movie data	Free account at themoviedb.org, under Settings > API
Proton WireGuard private key	The Gluetun VPN layouts	Your Proton account. See install-docker.md
Indexer logins or API keys	Searching	From each indexer you use

Browser

The web UI is a single-page app for current desktop and mobile browsers. No specific browser list is published. Below 900 px wide the sidebar becomes a drawer menu, so a phone works. It is not an installable app: “Add to Home screen” only creates a shortcut that opens a normal tab, and there is no offline mode.