Graywolf

Modern APRS station — software modem, digipeater, iGate, and web UI

Graywolf is a complete APRS station that replaces a hardware TNC with a software modem. Plug a radio into a USB sound card, install graywolf, and configure everything from your browser. No external sound card software, no config files to hand-edit — just a single binary and a web UI.

Graywolf dashboard showing station stats, DCD status, audio levels, and live packet feed
The dashboard shows real-time station status and a live packet feed

What You Can Do

Run a digipeater Set up a fill-in or wide-area digipeater with WIDEn-N path handling, duplicate suppression, and cross-channel routing. Configurable rules let you control exactly what gets repeated.
Run an iGate Bridge your local RF network to APRS-IS. Receive-only or bidirectional — gate RF packets to the internet and deliver APRS messages from the internet back to RF.
Beacon your position Fixed station beacons, GPS-driven mobile trackers with SmartBeacon rate adaptation, APRS objects for repeaters or events, and custom status beacons.
Serve as a TNC Expose KISS and AGWPE interfaces so other packet software (Xastir, YAAC, pinpoint, aprx, APRSdroid) can use graywolf as their modem over TCP, serial, or Bluetooth.
Combine everything Run a digipeater, iGate, position beacon, and KISS server all at once on the same radio channel — or spread them across multiple channels and radios.

Typical Setups

Home fill-in digipeater + iGate

The most common setup. A VHF radio on 144.39 MHz connected to a Raspberry Pi or small Linux box. Graywolf digipeats WIDE1-1 packets to fill coverage gaps in your area and gates everything it hears to APRS-IS. Add a position beacon so your station appears on the map.

Wide-area mountain-top digipeater

A high-site digipeater that handles both WIDE1-1 and WIDE2-2. No internet connection needed — just digipeating and a position beacon. Runs headless with systemd.

Mobile tracker

A GPS-equipped vehicle station that beacons its position as it moves. SmartBeacon adjusts the rate automatically — frequent beacons on the highway, infrequent when parked. Optionally serves as a KISS TNC for an in-cab APRS app.

Multi-radio gateway

A station with separate VHF and UHF radios. Graywolf can monitor both frequencies simultaneously, cross-band digipeat, and gate packets from both channels to APRS-IS.

Key Features

Software modem AFSK 1200, 9600 G3RUH, and PSK with FX.25 and IL2P forward error correction. No external modem hardware needed.
Live map Real-time APRS station map with trails, weather overlays, APRS-IS layer, and station popups showing path and heard-via details.
Web UI Configure and monitor your station from any browser. Live packet log, channel stats, and full configuration management.
Single binary One download, one SQLite database. No YAML to edit, no dependencies to install.
Runs anywhere Linux x86-64 and ARM (Raspberry Pi). Packaged for Debian/Ubuntu, RHEL/Fedora, and Arch.
Monitoring Prometheus metrics endpoint, live WebSocket packet stream, and structured logging.

What You Need

Getting Started

  1. Install graywolf and start the service. Open the web UI in your browser.
  2. Set up your audio device and create a radio channel for your APRS frequency.
  3. If transmitting, configure push-to-talk for your radio interface.
  4. Enable the features you need: beacons, digipeater, iGate, or KISS TNC.
  5. Check the monitoring page to verify packets are being received and your station is operating correctly.