This is the quickest way to get OOTT running. OOTT is published on Docker Hub as a pre-built image, [`rzuasti/oott`](https://hub.docker.com/repository/docker/rzuasti/oott/general), and the steps below get you to a running service with the smallest possible configuration.
You need somewhere on the host to store the configuration file and the database (OOTT uses SQLite, so the database folder should be on local — not remote — storage):
The user that runs Docker needs read access to the config folder and read/write access to the db folder. You can use any paths you like as long as you keep the volume mappings below in sync.
api_key="CHANGE_ME"# API key the app uses to talk to the backend — change this!
[notifications]
method="pushover"# Use "none" to only log notifications instead of sending them
[notifications.pushover]
token=""# Your Pushover application token
user_key=""# Your Pushover user key
```
This is enough to start the service; every other option falls back to a sensible default. See [Full list of configuration options](#full-list-of-configuration-options) for everything you can tune, and the [full sample config](https://github.com/rzuasti/oott/blob/main/examples/sample_oott.toml) for a commented, all-options file.
Create a `docker-compose.yml` at `/docker/oott/docker-compose.yml`:
```yaml
name:oott
services:
oott:
image:rzuasti/oott:latest
volumes:
- /docker/oott/config:/config
- /docker/oott/db:/db
network_mode:host
```
Host networking is required so OOTT can see the multicast and broadcast traffic its scanners rely on (see [Privileges and network ports](#privileges-and-network-ports)).
Start the service from where you placed the compose file:
```bash
docker compose up -d
```
That's it. Check that everything is running with `docker ps`, and follow the logs with `docker logs CONTAINER_ID -f`.
### Using the mobile apps
The OOTT app (web, desktop, iOS and Android) talks to the backend exclusively over its REST API on port `3000`. Open the app's settings and point it at your backend's address on the local network over HTTP, for example `http://192.168.1.50:3000`, using the API key you set in `web_server.api_key`.
This is the simplest setup and needs no extra infrastructure, but it only works while your phone is on the same local network as the backend.
> On iOS, the direct HTTP connection only works when you use the backend's **private-range IP address** (`192.168.x.x`, `10.x.x.x`, `172.16–31.x.x`) or a `*.local` (mDNS/Bonjour) name. A custom internal domain (e.g. `oott.mylan.com`) served over plain HTTP is blocked by iOS App Transport Security, even when it resolves to a private IP. Use the IP address directly, or set up HTTPS.
> The first time the iOS app reaches your backend on the local network, iOS shows a one-time "find devices on your local network" prompt. This is expected — tap Allow to continue.
To use a domain name, or to reach the backend from outside the local network, set up TLS as described in [Using HTTPS and domain names with the mobile apps](#using-https-and-domain-names-with-the-mobile-apps).
OOTT comes with a pre-built NixOS flake that you can integrate into your configuration. If you are not using flakes you can use the [flake code](https://github.com/rzuasti/oott/tree/main/nix) as a baseline and write your own derivation.
To integrate the OOTT flake into your config you generally do three things: add OOTT to your inputs, add its module and overlay, then enable and configure the service.
**3. Enable and configure OOTT** — in your `configuration.nix` (or an imported file). Set all options through the service definition; the keys mirror the config file options listed [below](#full-list-of-configuration-options):
The system configuration lives in a single config file, which you can write in TOML, JSON or YAML. With Docker, TOML is recommended — the [full sample config](https://github.com/rzuasti/oott/blob/main/examples/sample_oott.toml) lists every supported option with comments. With the Nix flake, set the same options through the service definition (see above).
|`networking.interface`|`eno1`|Network interface to use for scans. Optional — if not set, the first non-loopback connected interface is used automatically.|
|`arp_scanner.enabled`|`true`|Whether to run the ARP scanner. The whole `[arp_scanner]` section is optional; omit it to use the defaults below. Defaults to enabled; set to `false` to turn it off.|
|`arp_scanner.wait_between_scans`|`30m`|Time to wait between each network scan (you can express it in seconds, minutes, hours, etc. as a suffix - for example: 30s, 10m, 1h)|
|`arp_scanner.sender_timeout`|`1m`|If the ARP sender process takes longer than this it will be stopped (for a class C network - 254 IPs - it should take less than a minute)|
|`arp_scanner.scan_duration`|`10m`|How long to wait for response packets on each scan (5m to 10m is a good timeframe for a class B or C network)|
|`mdns_scanner.enabled`|`true`|Whether to run the mDNS/Bonjour scanner. Defaults to enabled; set to `false` to turn it off.|
|`mdns_scanner.probe_timeout`|`2s`|When an mDNS-discovered IP is not in the OS ARP cache, how long to wait for a targeted ARP probe reply to resolve its MAC address|
|`ssdp_scanner.enabled`|`true`|Whether to run the SSDP/UPnP scanner. Defaults to enabled; set to `false` to turn it off.|
|`ssdp_scanner.probe_timeout`|`2s`|When an SSDP/UPnP-discovered IP is not in the OS ARP cache, how long to wait for a targeted ARP probe reply to resolve its MAC address|
|`dhcp_scanner.enabled`|`true`|Whether to run the DHCP scanner. Defaults to enabled; set to `false` to turn it off.|
|`snmp_scanner.enabled`|`true` when the section is present, otherwise off|Whether to run the SNMP scanner. The whole `[snmp_scanner]` section is optional and the scanner stays off unless you add it; within the section it defaults to enabled.|
|`snmp_scanner.target`||SNMP agent to poll, as `host:port` (e.g. your gateway: `192.168.1.1:161`). The scanner reads the agent's ARP table over SNMPv2c — no local probing.|
|`snmp_scanner.community`||SNMPv2c read-only community string. Use a read-only community and never commit a real secret.|
|`snmp_scanner.wait_between_scans`|`10m`|Time to wait between polls. Keep it well under the agent's ARP cache timeout so active devices aren't missed.|
|`notifications.method`|`pushover`|For now just pushover, you can set this to "none" to avoid sending notifications (it will just log)|
|`notifications.notify_when_not_seen_for`|`1w`|Send a notification if a device comes back online after not being seen for this timeframe (you can use hours, weeks, etc.)|
|`notifications.pushover.token`||Your pushover token goes here, just copy&paste from their website after creating the app|
|`notifications.pushover.user_key`||User key goes here, this is the account wide code for pushover|
|`retention.window`|`365d`|How long to retain device events and notifications. Records older than this are purged daily. Accepts duration strings (e.g. `90d`, `1y`, `6m`). Defaults to one year.|
|`device_events.deduplication_window`|`1m`|Suppress duplicate device events: if the same scanner sees the same device (same MAC and IPv4) again within this window, only one event is recorded. Accepts duration strings (e.g. `30s`, `1m`, `5m`). Defaults to one minute.|
### Using HTTPS and domain names with the mobile apps
To reach the backend through a domain name, or from outside the local network, put it behind a reverse proxy (nginx, Caddy, Traefik, …) that terminates TLS with a **valid certificate from a trusted CA** (for example [Let's Encrypt](https://letsencrypt.org/)), then point the app at the HTTPS URL (e.g. `https://oott.example.com`). This works on every platform — including iOS — with no further configuration.
Connect using the **domain name the certificate is issued for**, not an IP address. Self-signed certificates are not supported unless they are manually trusted on the device.
OOTT stores a timestamped event in the database for every device detected on every scan. Storage therefore scales with three factors: number of active devices, scan frequency, and the retention window.
The figures below assume a 1-minute scan duration (`arp_scanner.scan_duration = 1m`) with a 1-minute wait between scans (`arp_scanner.wait_between_scans = 1m`), giving 720 scans per day, and a 365-day retention window. Assume all devices are continuously online (worst case).
A 15-minute wait (the default) cuts storage to about one eighth of the worst-case figures above — the medium office drops from up to 18 GB to roughly 2 GB per year.
**Event deduplication** — `device_events.deduplication_window` caps how often the same scanner can record an event for the same device. With several scanners (ARP, mDNS, SSDP, DHCP) reporting overlapping sightings, this collapses near-identical rows into one per scanner per device per window, trimming storage without changing scan timings. Widen it to keep fewer events; narrow it (or set it very small) to keep a finer-grained history.
The mDNS (UDP `5353`), SSDP (UDP `1900`) and DHCP (UDP `67`) ports are fixed by their respective protocols and **cannot be changed**. They must be available on the server where OOTT runs.
OOTT binds these sockets with address/port reuse, so it can run alongside other responders already listening on them (for example `avahi` on `5353`, `minidlna` on `1900`, or a DHCP server/relay on `67`). However, the ports must not be blocked by a host firewall, and the corresponding multicast/broadcast traffic must be allowed to reach the host — otherwise the scanners will not discover any devices.
> [!IMPORTANT]
> OOTT needs elevated privileges: the ARP scanner requires raw-socket access, and port `67` is a privileged port. The pre-built Docker image and NixOS module already run with what they need.
>
> Under Docker, the scanners require **host networking** (or an equivalent setup that exposes the host's multicast and broadcast traffic to the container), as shown in the [Docker installation](#simple-installation-with-docker) above.
