The stack that keeps a link alive when everything else is down.

Amateur radio does not map perfectly onto the OSI model, but the model shows where each part of OpenPulseHF lives. A message travels down the stack to the air — and back up on receive at the far station.

A multi-crate Rust workspace whose first release is deliberately narrow: one adaptive rate ladder with FEC on every rung, session compression, the daemon and CLI, and an ARDOP-compatible TNC for Pat. The rest of the stack — KISS/AX.25, Winlink B2F and the CMS gateway, QSY, mesh, relay, repeater, JS8 discovery, file transfer, the post-quantum handshake, GPU kernels and the GUIs — is in the code but ships disabled or experimental. All tests run against a deterministic loopback backend — no audio hardware is required to build or test.

Only the first three are part of Release 1. The others are implemented and tested in simulation, but ship disabled or experimental.

On-air status: a first rig-to-rig decode on 2 m passed on 28 July 2026 (phase A1, on the pre-v0.17 format), and the CE-SSB power and spectrum checks were made on real RF. The Release 1 on-air campaign (M3) has not run yet. Fade performance on HF is validated in the Watterson simulator only.

In Release 1 you drive the modem from the CLI against the background daemon (openpulse-server), or from Pat through the ARDOP TNC (openpulse-tnc). The GUIs are not part of Release 1; two of them are developer tools.

The test suite runs entirely against a deterministic loopback backend. No audio hardware, radio or station is required to build or test.

# Toolchain preflight (required: rustc >= 1.97.1)
./scripts/check-toolchain.sh

# Build (requires libasound2-dev on Linux for the CPAL audio feature)
cargo build --workspace

# Test suite — no audio hardware required
cargo test --workspace --no-default-features

# Lint
cargo clippy --workspace --no-default-features --all-targets -- -D warnings
cargo fmt --all -- --check

# Workspace gate (quote results only from its GATE: line)
scripts/gate.sh

# Benchmark regression gate
cargo run -p openpulse-cli --no-default-features -- --backend loopback --log error benchmark run

# Automated mode × channel test matrix (outputs to docs/test-reports/)
cargo run -p openpulse-testmatrix --no-default-features

Try it without a radio

A purely rig-less demo to get a first impression of the GUIs and the adaptive modem. None of it needs a radio or sound card, and none of it transmits.

# Two-station ARQ link simulator GUI — simulates BOTH stations over a virtual
# HF channel. Change SNR / channel model / mode live and watch the ladder adapt.
cargo run -p openpulse-linksim --features gui --bin openpulse-linksim-gui

# With the operator panel: --serve makes the simulator speak the daemon control
# protocol. Press Run in the simulator, then Connect in the panel (default 127.0.0.1:9000).
cargo run -p openpulse-linksim --features "gui,serve" --bin openpulse-linksim-gui -- --serve 127.0.0.1:9000
cargo run -p openpulse-panel   # in another terminal

For on-air operation, build the daemon or TNC with audio (--features cpal on openpulse-daemon and openpulse-ardop; the CLI has it by default) plus the PTT feature your backend needs (serial for RTS/DTR, gpio), and configure ~/.config/openpulse/config.toml — see the example config, the operator manual and the on-air test plan.

OpenPulseHF is GPL v3, but these interfaces let non-GPL software interoperate without GPL obligations — each sits behind a process or network protocol boundary. Note that plugins which statically link openpulse-core are derivative works and must be GPL-compatible; the only supported path for a proprietary DSP backend is a separate process bridged over one of these interfaces.