One app from antenna to award. Eleven modes, real rig control, APRS, propagation, DX chasing, and a logbook that computes your awards offline.

_{Offline installer, bundles WebView2 and Hamlib, per-user install, no admin rights. · Operator manual · Comprehensive overview}

Nexus is a free, GPLv3, all-mode amateur radio operations center for the desktop. It puts a WSJT-X-parity FT8/FT4 cockpit, seven more WSJT-X modes that transmit as well as receive, RTTY, SSTV, APRS with a live symbol map and an iGate, a CW keying station with an AI decoder (DeepCW model by e04), an SSB phone cockpit with a real RF panadapter, a live propagation map, an evidence-backed "work this now" board, a POTA/SOTA hunter, a club-ready Field Day mode, satellites with rotor tracking, and a DXCC-first logbook with LoTW / QRZ / ClubLog / eQSL connectors into one window, across up to three radios, with one log.

It is built in Rust (DSP, sequencing, CAT, networking) behind a Tauri desktop shell, and it treats WSJT-X as the golden standard for FT8/FT4 behavior. The auto-sequencer state machine, decode cadence, split handling, Hound mode, and the UDP ecosystem protocol all match stock, so your WSJT-X muscle memory works unchanged inside a UI built this decade.

• 🎛️ All-mode, one app. Digital, CW, and phone cockpits share one rig, one CAT layer, one logbook, and one needs engine. Entering a cockpit sets the rig up for it automatically: a DATA submode for digital, CW for the keyer, the correct sideband by band for phone. No mode fumbling, no app switching, no five stitched programs.
• 📡 WSJT-X operational parity in a modern shell. The FT8/FT4 core replicates the stock behavior the whole ecosystem depends on: the QSO sequencer state table, the early decode pass at 11.8 s, Split Operation (Rig / Fake It), Hound mode, directed CQ, the Tx1–Tx6 panel, the F-key shortcuts, and the full WSJT-X UDP protocol, so JTAlert, GridTracker, and loggers see Nexus as a WSJT-X. A Classic ↔ Roster toggle gives you the stock layout or a modern sortable call roster.
• 📻 Every mode transmits, each with its own rhythm. FT8, FT4, Q65, FST4, FST4W, MSK144, JT65 and WSPR, plus the two Tempo tiers. Every waveform was verified by generating a transmission in Nexus and having stock WSJT-X decode it, rather than by testing Nexus against its own decoder, since both halves come from the same vendored source and a shared misreading would pass unnoticed. Q65 was additionally matched sample-for-sample against WSJT-X's own generator at 0.9985 correlation. Each mode keeps its own operating discipline: MSK144 waits twelve transmit periods before giving up on a contact where FT8 waits three, and WSPR and FST4W never touch the QSO sequencer at all.
• 🔬 A decoder measured against the reference. The FT8/FT4 modem is built from WSJT-X's own DSP sources, tracking upstream 3.0.2. On identical recorded audio, the decode floor measures −21.3 dB against stock WSJT-X's −20.7, with zero false decodes, and the suite includes false-alarm tests that feed the decoder pure noise and require it to produce nothing at all. Rovers keep decoding here: upstream 3.0.2 discards any decode containing /R outside contest mode, which is exactly the VHF traffic worth catching, and a test fails if anyone reintroduces that filter.
• 🗺️ APRS that shows you the network and tells you the truth about your receiver. Stations draw as their actual APRS symbol rather than identical dots: cars, trucks, bicycles and people, weather stations, digipeaters and iGates, campsites, balloons, boats and aircraft, with vehicles under way pointing their heading and an operator's overlay character (the I on a full iGate, the R on a receive-only one, a digipeater's hop count) drawn on top. Colour says what a station is, and the ring around it says how it reached you: solid for your own RF, doubled when you heard it both ways, dashed and dimmed for internet-only. Click any station for a detail card with what the symbol means in words, per-source ages kept separate ("your receiver decoded this 4 min ago; the internet feed reported it 20 s ago" are two different facts and only one says anything about your antenna), grid, distance and bearing, course, speed and altitude, the digipeater path, whether it arrived direct or digipeated, decoded weather-station readings (temperature, wind, gusts, rainfall, humidity, pressure, with a sensor the station does not have left out rather than reported as zero), the raw packet, and one click to QRZ or aprs.fi.
• 🔍 An APRS screen that names the actual fault. An empty APRS map used to mean half a dozen different things and looked identical for all of them. Now it says which one: the radio is on the wrong frequency ("on 144.174 USB — APRS needs 144.390 FM", with a Tune button, judged against the channel you selected so 144.800 in Europe is correct and not a warning), the right frequency in the wrong mode, a closed squelch (alive, no level, not a fault) as distinct from no input at all (which really is a dead capture device), the input level in dBFS with the window it measures, or which of your radios it is listening to. Every claim is dated, so a count from six minutes ago can no longer assert something about the present. The packet decoder is measured against tone imbalance ("twist") and still decodes with the tones 24 dB apart, far beyond the roughly 9 dB real signals show.
• 🌐 APRS-IS, in and out. Connect to the internet side of APRS and plot what the wider network reports near you alongside what you actually hear, with a radius around your grid, watched callsigns that come through from anywhere, and read-only access that needs no passcode. It doubles as a diagnostic: internet stations arriving while your RF chip stays silent tells you the fault is in the radio chain rather than the app. You can also run a receive-only iGate and contribute what your own antenna hears to the global map. Nexus honours every rule the network asks of an iGate (never re-gates an internet packet, respects NOGATE and RFONLY, suppresses duplicates, caps its own upload rate) and never gates the other way, because that direction means a radio keying up unattended.
• 🎚️ Real rig control, not just CAT. On a native-CI-V Icom (IC-7300 / 7610 / 9700 / 705 / 905) Nexus drives the radio directly and streams the rig's own spectrum scope into the cockpit as a real RF panadapter, alongside AGC speed, noise reduction and blanker, notch, filter width, mic gain, and SWR / ALC / power / compression meters on the rig's own calibration curves. FlexRadio streams the SmartSDR panadapter and DAX audio over the network (VITA-49), which keeps working under Remote Desktop where the DAX sound devices are invisible. Every other rig runs through bundled Hamlib and still gets click-to-tune and drag-a-passband on the audio scope.
• 🔧 Rig control that recovers by itself. Nexus stops polling a radio that has stopped answering, which is right, but that state used to be permanent: any hiccup cost you rig control until you restarted the app. It now retries quietly, backing off to about once every thirty seconds, and picks the radio back up within a couple of seconds of it answering again. It also reads what your radio actually covers out of the rig's own capability table, so an HF-only radio is never commanded to 2 m in the first place, and a refused command is treated as a refusal rather than believed.
• ⏸️ A waterfall you can rewind. Pause and roll the wheel back through the last few minutes of the band, with a time tape showing how far back you are, then snap to live. History keeps recording while paused. A 3-D stacked-spectrum view reads band activity at a glance. Both work on the FT waterfall and on the Phone/CW panadapter.
• 🧭 An honest "work this now" board. Every Needed row shows its evidence, as in "heard by K9LC (EN52, 26 km), 4 min ago", and admission is gated by corroboration rules: multiple receivers near you, Es-patch locality on VHF, reciprocal-path checks. A superstation on a mountain can't tell you a band is open when it isn't open at your QTH. One click QSYs the rig, opens the right cockpit, and prefills the log, with split offsets parsed from cluster comments. A packed callsign→state index built from the FCC license file resolves NEW STATE on CW, SSB and cluster spots that carry no grid at all.
• ⚡ Pounce. Working a rare station is a race, and once the pileup builds you have lost it. Nexus scores every skimmer and cluster spot as it arrives and, when something you actually need turns up, plays a distinct tone whether or not Nexus is the focused window, raises a desktop notification, and shows a banner with the call, the entity and the frequency. One click works it. Nexus never touches the radio on its own for this. It tells you, and you decide. Off until you switch it on, because how often it fires depends entirely on how much you still have to chase.
• 🏆 A logbook that chases awards properly. DXCC, DXCC Challenge, Honor Roll, WAS, WAZ, per-band VUCC and IOTA computed offline from your log, with source-aware confirmations (eQSL and QRZ never silently count toward LoTW-grade awards), two-pull incremental LoTW sync, hourly QRZ confirmation pulls as a delta, a per-QSO upload state machine that survives restarts, callbook autofill, and a local-only Journey achievement layer that makes the first 100 QSOs as motivating as the last 10 entities. Editing a contact that has already gone out re-sends it, so the online logbooks can't quietly disagree with yours.
• 🗺️ Propagation you can act on. A live world map (3-D globe, azimuthal beam map, or flat) fused from PSK Reporter, RBN/DX-cluster, and NOAA space weather, with a solar-flare layer, aurora, and measured MUF. A native in-app port of ITU-R P.533, the VOACAP-class link-budget standard, with no external binary to install. An opening detector anchored to your QTH with reciprocity gates and propagation-mode classification (Es / F2 / aurora / tropo), tiered alerts that go loud only for the rare and brief, opening sectors drawn on the map, and a persistent openings log so you can ask "how many real 2 m openings this month, and did I catch them?"
• 🛰️ Satellites and DXpeditions. Pass schedules, polar plots, Doppler, favorites, true 3-D orbits at real altitude with footprint rings, and rotor auto-track through a pass. A DXpedition month calendar where each operation is a single coloured bar across the days it is on the air, carrying its announced bands low-first, with the modelled best band and time for each, wake-me alarms, and one click through to the team's own page (or the callsign's QRZ page when there isn't one).
• 🏞️ POTA, SOTA and Field Day. Live activator spots with NEW PARK and BAND OPEN badges and a one-click HUNT. ARRL FD and Winter FD event modes with correct date rules and scoring (per-mode points, dupes per band per mode, legal power tiers, live bonus checklist), a worked-sections board for all 83 sections, submittable Cabrillo 3.0, and every contact pushed in real time to the club's N3FJP master log over its official TCP API and broadcast as native N1MM+ <contactinfo> datagrams. The event log is journalled, so a mid-event crash comes back with your log intact.
• ♿ Accessibility that is always on. Screen-reader support for JAWS and NVDA with no "accessibility mode" to enable and nothing changed for sighted users: the QSO sequencer is announced as it advances, transmit/receive switches are announced assertively, and the band activity, Call Roster and Needed lists are keyboard-navigable (arrow to read a row, Enter to select, Shift+Enter to work, Alt+Enter to ignore). Optional spoken decodes, a TX/RX earcon, and a per-cycle decode tick are there for operating by ear.
• 🔌 Zero-config setup, with a real transmit lockout. Plug in the radio and click Detect my radio: Nexus reads the USB descriptors, matches the rig model, pairs the audio CODEC, and links the one driver you need if it's missing. Digirig and RIGblaster interfaces are recognised by name. Hamlib ships inside the installer. A goal-driven first-run wizard shapes the app to you, and your declared license class becomes a real Part 97 transmit lockout, a software guard in every TX path. Launching Nexus opens the rig read-only and commands nothing until you act, so a radio parked on 40 m LSB for a net stays there.
• 💬 The Tempo protocols. Original weak-signal waveforms: TempoFast (a coherent 4-CPM tier on a four-second conversational cycle with incremental-redundancy HARQ, where a failed decode is not wasted because retransmissions combine until the message lands) and TempoDeep (a non-coherent 8-FSK tier for fading paths). No other amateur text mode accumulates redundancy across retransmissions. Both have closed real links on the air, including a completed two-station QSO on 6 m. Sensitivity figures are still simulation numbers, and on-air decode reports are the single most useful contribution you can make.
• 🔁 It updates itself. A new version downloads quietly in the background and then offers to install. Nothing installs behind your back and nothing happens on a schedule: the button waits for you, and stands down while you are transmitting, tuning, in a contact or running CQ, and tells you which. Every update is signed and verified before it is applied.
• 📻 Program and Memories. Search the repeaters around any location and star one straight from the results: it saves into Memories as a proper FM channel with the machine's shift, offset and access tone, and lands on the quick-recall strip in the Phone, Operate and CW cockpits, where one click or Ctrl+1 through Ctrl+9 tunes it. Starred repeaters remember where the machine physically is, so Memories shows distance and bearing measured from your current grid each time, which means the numbers follow you when you operate portable. A per-repeater Tune names FM explicitly, so the frequency, shift, offset and tone all land together on the radio you mapped for FM rather than on whichever rig was last in use. Export a CHIRP-ready CSV (CHIRP flashes roughly a thousand radio models), and Nexus warns you when the directory has a whole band missing rather than letting a short list look finished. Memories also ships 11 curated packs (172 channels) with opt-in reminders before a net starts.

The new ham. Nexus compresses the painful first month into an afternoon: auto rig detection instead of driver archaeology, a wizard that asks what you want to do rather than what you know, a license-class lockout so you can't transmit out of segment, an auto-sequencer that completes FT8 QSOs while you learn the flow by watching, a Needed board that says who to work and why, and a Journey layer that celebrates your firsts. When something doesn't work, the app tries to name the actual fault rather than leaving you to guess: which radio it is listening to, whether the dial is even on the right frequency, whether that silence is a closed squelch or a dead sound card. You can be making contacts the day your callsign hits the FCC database.

The WSJT-X operator. Same gestures, same flow: double-click semantics straight from processMessage, Esc / F4 / F6 / Alt+1–6, Band Activity bottom-pinned in chronological order, early decodes at 11.8 s, Fake-It split keeping TX audio in 1500–2000 Hz, Hound auto-move on the Fox's report. Plus what stock never had: country and need annotations on every decode row, a sortable roster view, in-app LoTW/QRZ sync, always-on decode (no accidental deaf Monitor-off), the rig's real panadapter, and seven more modes without launching anything else.

The DX chaser. ATNO / new-band / new-mode / new-zone ranking across all bands simultaneously rather than just the one you're tuned to, DXpedition tracking with workable-now cards and modelled windows, cluster split comments ("UP 2") parsed and applied to the rig at click time, Pounce on the skimmer feed, Honor Roll math, and confirmation diagnostics that explain exactly why a QSO isn't credited yet, with a one-click fix where one exists.

The rag chewer. Awards and rate are not the point for everyone. Phone and CW get a real panadapter with click-to-tune, DSP controls that mirror the front panel, and a one-line recall card showing their name and your history with them while you operate. CW macros greet the other operator by name and send your state ({HISNAME} / {MYSTATE} / {HISSTATE}). Your local repeaters and nets are a hotkey away, with distance and bearing to each machine.

The club. Field Day mode reshapes the app for the event weekend and feeds club infrastructure natively, with no JTAlert bridge and no end-of-day log merges. Plus a built-in CAT broker so other shack software can share the radio through Nexus.

A band on its own is not a fine enough rule. If you run a 2 m/70 cm rig for weak-signal digital and a different rig for FM and APRS, both cover 2 m, and something has to decide which one a 2 m FT8 spot goes to and which one an APRS tune goes to.

• Route on band and mode. Settings ▸ Radio carries a routing table under your radios: pick a set of bands, pick a mode class (weak-signal digital, FM & APRS, SSB phone, CW, RTTY), pick the radio. Rules are checked top to bottom, first match wins, and the arrows beside each rule reorder them. Anything unmatched falls back to each radio's band coverage and then to a default radio you nominate. A three-radio shack usually fits in two rules. There is a "Where would this go?" control that resolves a band and mode to a radio without touching a rig, and it asks the same code the radio does, so it cannot tell you one thing and then do another. Add no rules and routing stays band-only, exactly as before.
• One window, up to three rigs. Every radio stays permanently connected. The non-active rigs are monitored live (frequency and S-meter in the top-bar switcher) and switching is an instant handoff with no CAT teardown, so the dial never bounces. Each radio carries its own CAT, audio, rotator, keying port and band coverage, and the routing table is shared across windows, because which rig does 2 m FM is a fact about your station rather than about one window.
• Two windows, one logbook. For simultaneous decode on more than one rig, launch a second instance pointed at another radio. Both share one logbook, reconciled field by field, so a contact edited in one window is merged rather than clobbered in the other, and each window keeps its needs fresh as the shared log changes.
• Peg-lock pins the active radio and stops all automatic switching.

Credentials for every service live only in the OS keychain, never in config files, never in logs, and never shown back to the UI beyond "configured."

1. Download the file for your platform. Every release carries all five, built from the same tree:

   File	Platform
   Nexus_1.0.0_x64-setup.exe	Windows 10/11 x64 — NSIS, per-user, no admin rights, bundles WebView2 and Hamlib so it works offline
   Nexus_1.0.0_amd64.AppImage	Linux on a PC, portable — one file, runs from anywhere, updates itself in place
   Nexus_1.0.0_pc_amd64.deb	Debian / Ubuntu on a PC — apt-managed, pulls libhamlib-utils in for CAT
   Nexus_1.0.0_pi_arm64_bookworm.deb	Raspberry Pi OS bookworm, 64-bit (Pi 3/4/5)
   Nexus_1.0.0_pi_arm64_trixie.deb	Raspberry Pi OS trixie, 64-bit (Pi 3/4/5)

   The .deb names are new in 1.0.0. The PC and Pi packages used to be told apart only by amd64 versus arm64, so picking the right one meant already knowing that amd64 means "PC" here — the names say pc and pi now, and the Pi files name their OS base.

   The two PC Linux files need Ubuntu 24.04 or newer (Debian 13, Fedora 40+, Mint 22 — anything with glibc 2.39 or later; check with ldd --version). The AppImage is no exception: it carries the app's own libraries but not the system C library. On an older distro both install cleanly and then fail to start, so it is worth checking first. See Install → What you need.

2. Plug in the radio, open Settings ▸ Rig & Audio, click Detect my radio.

3. Answer the first-run wizard: callsign, grid, license class, and what you want to do.

4. Watch decodes arrive. Double-click a station, the sequencer runs the QSO, and the contact lands in the logbook, on PSK Reporter, and (if configured) on QRZ and LoTW.

New here? Start with Getting Started.

The installer is unsigned (cross-compiled on Linux), so SmartScreen may warn: More info → Run anyway. Verify the download against the SHA-256 published on the release page.

On a slower Raspberry Pi, Settings ▸ Decode depth ▸ Fast keeps FT8/FT4 decoding in real time.

1.0.0 closes the beta period, and what that claims is narrow: the modes, the rig control, the logbook and the awards engine have been run on the air through that period, on more than one station and on rigs the author does not own. It does not claim nothing is left. Every line below still says what a thing does not do, and so does every entry in the changelog.

• The FT8/FT4 tier is the production core: operational parity with stock WSJT-X, verified against a 207-row behavior matrix, over a thousand automated tests, wire formats pinned by test, and exercised on the air daily.
• Field-verified end to end on Yaesu (FTDX10, FT-991A) and on native-CI-V Icom, where the IC-9700's real panadapter streams live.
• APRS is on the air, receiving and mapping, with the internet feed and the receive-only iGate confirmed against a live APRS-IS connection. Transmit (beacons, messages, acks) stays behind an explicit TX arm; opening the screen only ever starts a receive-only decoder.
• The FlexRadio native path (SmartSDR panadapter, DAX RX and TX audio, native meters) is opt-in, off by default, and not yet confirmed on hardware here. Turn it back off if decodes stop.
• The TempoFast/TempoDeep tiers work on the air (first decode 2026-07-21, first two-station QSO 2026-07-26), and their sensitivity figures are still simulation numbers. On-air decode-rate-vs-SNR is the open gate and the single most useful contribution you can make.
• CW and Phone cockpits are casual and ragchew grade by design: macros, voice keyer, panadapter, live decoder, WinKeyer support, full logging. No contest exchanges.
• Windows, Linux and Raspberry Pi builds ship together every release.
• Not implemented yet: contest modes (NA VHF, RTTY RU, WW Digi), the Fox role (running a DXpedition end), transmit-side iGating (deliberately never, since it means a radio keying up unattended), and programming DMR / D-STAR / Fusion repeaters (they are listed with badges so you know they're there). Shared RepeaterBook access for every user, with no token to set up, is pending RepeaterBook's approval; until then Program uses the open hearham.com directory by default and your own RepeaterBook token if you add one.

┌────────────────────────────────────────────────────────────────┐
│ Tauri v2 desktop shell (src-tauri) + web UI (ui/, React + TS)  │
│   cockpits: Operate · CW · Phone · RTTY · SSTV · APRS · Tempo  │
│   boards: Needed · Spots · POTA/SOTA · Logbook · Awards ·      │
│           Journey · Connect map · Satellites · Memories        │
├────────────────────────────────────────────────────────────────┤
│ Rust core (crates/)                                            │
│   tempo-app    live TX/RX engine · settings · DTOs             │
│   tempo-core   slot timing · 77-bit messages · QSO sequencer · │
│                logbook/ADIF · Field Day · RTTY · reconcile     │
│   tempo-audio  cpal audio · rigctld CAT · native CI-V · CW     │
│                keyer · voice keyer · decode scheduler · broker │
│   tempo-net    WSJT-X UDP · PSK Reporter · DX cluster ·        │
│                APRS-IS · LoTW/QRZ/ClubLog/eQSL · N3FJP ·       │
│                N1MM · DXKeeper                                 │
│   propagation  needs engine · opening detector · P.533 ·       │
│                space wx · awards · Journey                     │
│   per-mode     ft8 · ft4 · q65 · fst4 · msk144 · jt65 · wspr · │
│                modes · tempo-sstv · deepcw                     │
│   tempo-fast / tempo-fast-sys   safe wrapper + FFI over libtempo│
├────────────────────────────────────────────────────────────────┤
│ libtempo (Fortran → C ABI, FFTW3, no Qt)                       │
│   FT8/FT4/Q65/FST4/FST4W/MSK144/JT65/WSPR encode+decode        │
│   (vendored WSJT-X DSP) · TempoFast 4-CPM turbo + IR-HARQ ·    │
│   TempoDeep non-coherent 8-FSK + soft LDPC                     │
└────────────────────────────────────────────────────────────────┘

See ARCHITECTURE.md and docs/ARCHITECTURE.md for the full design.

git clone https://github.com/kd9taw/Nexus.git nexus
cd nexus
cargo test --workspace                  # Rust core (NOTE: this excludes src-tauri)
cargo test --manifest-path src-tauri/Cargo.toml --lib --features radio
cd ui && npm install && npm test        # UI suites (vitest)
# Windows installer, cross-compiled from Linux/WSL2:
./scripts/build-windows-cross.sh
# Linux .deb + AppImage:
./scripts/build-linux.sh

The modem is Fortran + C behind a Rust FFI, so the GNU toolchain is required. See Building from Source and WINDOWS.md.

• Comprehensive overview — every surface, in depth
• Operator manual — setup, per-mode operating guides, integrations, troubleshooting
• Tempo protocol specification — the native waveforms, for implementers
• Frequency plan — where the TempoFast/TempoDeep tiers live on the bands
• Changelog — every release, in operator-facing prose

Nexus is free software under the GNU GPL v3 (GPL-3.0-only).

• WSJT-X — Joe Taylor K1JT, Steve Franke K9AN, Bill Somerville G4WJS, and the WSJT Development Group. Nexus's digital modem (libtempo/) is derived from WSJT-X: the FT8/FT4 codec, the 77-bit message packing, the LDPC(174,91) FEC, the CRC-14 check, and the Q65 / FST4 / FST4W / MSK144 / JT65 / WSPR mode sources are their GPL-licensed work, vendored and reused via a foreign-function interface (see NOTICE for the full lineage and marked modifications). Nexus interoperates with their ecosystem over the standard WSJT-X UDP protocol; its auto-sequencer is original Rust modeled on WSJT-X's on-air behavior. Nexus is not endorsed by nor affiliated with the WSJT Development Group. GPLv3.
• qracodes — Nico Palermo IV3NWV / Microtelecom Srl (© 2016, GPL-3.0-or-later). The Q-ary Repeat-Accumulate LDPC codec that Q65 decodes with, vendored at libtempo/vendor/wsjtx/lib/qra/ with its per-file license headers intact. A separate copyright from the WSJT Development Group's, credited separately for that reason. Nexus does not vendor or link the same author's SuperFox polar-code tables, which are not free software — see NOTICE.
• TempoFast / TempoDeep — the native weak-signal waveforms by KD9TAW.
• AetherSDR (GPLv3) — the waterfall's 3D stacked-spectrum view (ui/src/dss.ts) and retained-history model (ui/src/waterfallHistory.ts) are ported from AetherSDR's DssRenderer / WaterfallHistoryBuffer; its PanadapterStream was a wire-format reference for the native Flex DAX/VITA path (see NOTICE).
• fldigi (GPL-3.0-or-later) — Dave Freese W1HKJ and Stefan Fendt DL1SMF (descended from Tomi Manninen OH2BNS's gmfsk). Nexus's RTTY demodulator (crates/tempo-core/src/rtty/demod.rs) is ported from fldigi's receive path (rtty.cxx + fftfilt.cxx), implementing Kok Chen W7AY's published ATC design as fldigi does; lineage and the deliberate differences are in NOTICE.
• slowrx (ISC) — Oona Räisänen OH2EIQ's SSTV decoder, by way of the MIT slowrx.rs Rust port by Jason Herald. Nexus's SSTV receiver (crates/tempo-sstv/) is vendored from it; the SSTV transmitter is original Nexus code (see NOTICE).
• DeepCW (AGPL-3.0) — e04. The neural-network model behind Nexus's primary CW decoder, shipped as an app resource (resources/deepcw/) with its full AGPL-3.0 license text bundled in the installer; its corresponding source is the upstream repository (see NOTICE).
• SatNOGS / the Libre Space Foundation (CC BY-SA 4.0) — the open satellite database and network of volunteer ground stations. Nexus's amateur-satellite list is derived from the SatNOGS DB: which birds are in orbit, what they are transmitting, and whether they are still alive — the curation no orbital-element source can provide. That derived catalog is published by this project every six hours and downloaded by every install, and a snapshot of it ships inside the installer so a new install has the full bird list before its first fetch — under CC BY-SA 4.0 with attribution carried inside the file. Their Doppler data serves a second purpose: Nexus's Doppler prediction is checked against carrier tracks recovered from eight real recorded passes on their network, so it is validated against signals that actually arrived at an antenna and not only against another implementation of the same theory. Thanks to stations 1696, 4803, 5049 and 5062 and their operators (see NOTICE for what is redistributed where).
• Hamlib — bundled rigctld for CAT control (GPL/LGPL).
• FFTW (GPL), Tauri, React, cpal, alsa-rs (Linux device names), Natural Earth basemap (public domain), repeater data courtesy of hearham.com and RepeaterBook.com, city search powered by OpenStreetMap.

This is experimental amateur-radio software. You are responsible for operating within your license privileges and local regulations. Nexus never transmits on launch; ARRL Field Day prohibits fully-automated contacts, and Nexus's Field Day workflow is operator-initiated by design.

Author: KD9TAW · kd9taw@protonmail.com · contributions welcome — see CONTRIBUTING.md and the Code of Conduct.