Configuration Reference
Most configuration is done from the web UI and persisted to a single JSON file. This page is the reference for what's stored and the environment variables that influence startup.
The config file
config.json lives in the data directory (default /var/lib/omnibus,
./data/ in dev). It is auto-created and holds:
| Key | Contents |
|---|---|
admin.users[] | {id, username, passwordHash, role, createdAt} per user. |
mqtt | Broker URL, credentials, base topic, Sparkplug settings. |
tcp.basePort | Starting TCP port for new serial ports (default 9000). |
ports[<path>] | Per-port adapter, mode, serial settings, outputs, assigned TCP port, and MQTT prefix. |
onboarding | First-run wizard state ({completed, completedAt, steps}). |
usbReset.preserve | Top-level keys to keep across a USB factory reset. |
button | Argon-button gesture settings (if enabled). |
The data directory also holds audit.log and the TLS material (ca-cert.pem,
ca-key.pem, cert.pem, key.pem, cert-sans.txt).
:::tip Don't hand-edit on a running box
Prefer the UI or the API. If you must edit config.json directly, stop the
service first, keep ownership omnibus:omnibus, and restart.
:::
Environment variables
Set these in the systemd unit (or a systemctl edit omnibus drop-in).
Runtime
| Variable | Default | Purpose |
|---|---|---|
PORT | 80 (48879 in dev) | HTTP port. |
HTTPS_PORT | 443 | HTTPS port. |
OMNIBUS_DATA_DIR | /var/lib/omnibus | Where config/audit/TLS live. |
NODE_ENV | production (prod) | Serves the built client vs. Vite dev middleware. |
OMNIBUS_TLS_CERT / OMNIBUS_TLS_KEY | — | PEM paths to override the internal leaf with a public cert. |
OMNIBUS_MDNS_DISABLE | — | Set to 1 to disable mDNS advertising. |
Branding / white-label
| Variable | Default | Purpose |
|---|---|---|
OMNIBUS_PRODUCT_NAME | OmniBus | Product display name. |
OMNIBUS_VENDOR | Harness Automation | Vendor name. |
OMNIBUS_SUPPORT_EMAIL | support@harnessautomation.com | Support contact. |
OMNIBUS_PRODUCT_URL | (empty) | Vendor product page. |
Installer (environment)
| Variable | Default | Purpose |
|---|---|---|
INSTALL_DIR | /opt/omnibus | Deploy target. |
OMNIBUS_DATA_DIR | /var/lib/omnibus | Persistent data dir. |
Default ports
| Port | Service |
|---|---|
80 / 443 | Web UI + REST API + WebSocket (HTTP/HTTPS). |
48879 (0xBEEF) | Dev server (npm run dev). |
9000+ | Per-serial-port TCP servers (from tcp.basePort). |
47808 | BACnet/IP (gateway mode, configurable). |
20000 | DNP3 over TCP. |
502 | Modbus/TCP (when connecting out as a TCP client). |
5353/udp | mDNS. |